Directory UMM :Data Elmu:jurnal:E:Environmental Management and Health:Vol08.Issue2.1997:
Environment and human health: a threat to all
Rajendra Ramlogan
Unive rsity o f Cambridge , UK
Focuses on the direct and
indirect impact of environmental abuse on human
wellbeing. In some instances,
the impact of environmental
abuse on human health is not
still unknown, merely being
subject to scientifi c suspicion. This would suggest
caution and the need for
preventive measures to be
applied. The threat to human
health from environmental
factors is not an isolated
problem that exists on a
national level. There are
environmental factors that
affect human health on a
global level or are so widespread as to be considered
global problems. Other environmental problems cross
national boundaries and
achieve regional importance.
Enviro nme ntal Manage me nt
and He alth
8 / 2 [ 1997] 5 1 –6 6
© MCB Unive rsity Pre ss
[ ISSN 0956-6163]
Introduction
Th e wor ld th a t we in h a bit h a s been sh a ped
la r gely by a cts of n a tu r e a n d of m a n . Th e
su bject of th e sh a pin g of th e en vir on m en t by
n a tu r a l for ces a n d its effect on m a n does n ot
for m pa r t of th is r eview. In stea d th is pa per is
dedica ted solely to a n a n a lysis of th e r ole of
m a n in th e a bu se of th e en vir on m en t a n d th e
exten t to wh ich th is a ffects h u m a n h ea lth a n d
wellbein g. Th er e is a lon g lita n y of m a n ’s
m isu se of h is en vir on m en t, a n d eviden ce
sh ow s th a t th e situ a tion h a s wor sen ed dr a m a tica lly over th e la st 300 yea r s. Th e con fl ict
a ppea r s to h ave in ten sified, cr ea tin g con cer n
th a t we m ay be pu sh in g ou r selves to th e
br in k of a globa l disa ster. F a ctor s su ch a s th e
In du str ia l Revolu tion of th e m id-eigh teen th
cen tu r y, wh ich sta r ted in Br ita in a n d m a de
its w ay to E u r ope a n d N or th Am er ica , a n d
th e in sa tia ble a ppetite for fu el, a n d th e gr ea t
tech n ologica l str ides th a t a ccom pa n ied th e
In du str ia l Revolu tion , u r ba n iza tion , th e com m er cia liza tion of a gr icu ltu r e, th e r ise in
con su m er ism , a n d popu la tion gr ow th , h ave
often been h er a lded a s th e tu r n in g poin t for
th e m oder n cr isis th a t h a s a r isen between
m a n a n d th e en vir on m en t. Yet despite th e
ea r ly sta r t to en vir on m en ta l pr oblem s, it is
per h a ps tr u e th a t a s th e twen tieth cen tu r y
pr epa r es to give w ay to th e twen ty-fir st, th e
fu ll sca le of th e h ea lth im plica tion s of en vir on m en ta l de gr a da tion h a s sta r ted to be
r evea led.
Good h ea lth h a s been on e of th e m a jor goa ls
of h u m a n k in d th r ou gh ou t th e m a r ch of h istor y. Th e Wor ld Hea lth Or ga n iza tion (WHO)
defin es h ea lth a s th e sta te of com plete ph ysica l, m en ta l a n d socia l wellbein g of m a n ; n ot
m er ely fr eedom fr om disea se or in fi r m ity
(Weisn er, 1992, p. 1). It h a s been a r gu ed th a t
th e ba sic r equ ir em en ts for a n a ccepta ble level
of h ea lth a r e a su ita ble diet, decen t sh elter,
com pa n ion sh ip, a n a dequ a te in com e a n d a
h ea lth y en vir on m en t. Im por ta n tly, good
h ea lth r equ ir es a con str u ctive ba la n ce
between in dividu a ls or gr ou ps a n d th e en vir on m en t (Weisn er, 1992, pp. 2-4). It is bein g
r ecogn ized th a t th e ph ysica l en vir on m en t is
th e m ost im por ta n t deter m in a n t of good
h ea lth a n d, con sequ en tly, pr otection of th e
en vir on m en t a n d pr eser va tion of ecosystem s
a r e fu n da m en ta l in th e str u ggle a ga in st
h u m a n illn esses (Cor tese, 1993, pp. 1-3). E xistin g eviden ce su ggests th a t th e m ost ser iou s
poten tia l con sequ en ce of globa l en vir on m en ta l ch a n ge is th e decim a tion of th e E a r th ’s
life-su ppor t system s (McMich a el, 1993, p.
xiii). Cor tese h a s a sser ted th a t r a pid in du str ia l gr ow th , th e popu la tion explosion ,
r esou r ce depletion , a lter a tion of th e ch em ica l
com position of th e a tm osph er e a n d th e
cyclin g of ca r bon , n itr ogen a n d ph osph or ou s
a r e fa ctor s la r gely r espon sible for a lter in g
th e ba sic ph ysiology of th e E a r th (Cor tese,
1993, p. 2; Godlee a n d Wa lk er, 1992, pp. 1-8). In
th e wor ds of McMich a el (1993), it wou ld
a ppea r “th a t th is fa br ic of life-su ppor tin g
m ech a n ism s is n ow sta r tin g to u n r avel, in a
br ief geologica l m om en t, a s th e cu m u la tive
globa l im pa ct of h u m a n a ctivity esca la tes”
(p. 5)”.
On e of th e in cr ea sin gly a ppa r en t fea tu r es of
life in th e la tter h a lf of th e twen tieth cen tu r y
is th e gr ow in g in ter depen den cy of th e globa l
villa ge. Th is tr en d tow a r ds a sm a ller, m or e
a ccessible a n d in ter r ela ted wor ld h a s ju stifi a bly led to m a n y differ en t a r ea s of con cer n ,
on e of wh ich per ta in s to th e en vir on m en t.
Developin g a u n ifor m defin ition of wh a t is
m ea n t by th e ter m “en vir on m en t” h a s pr oved
elu sive. For pu r poses of th is pa per, a wor k in g
defin ition of th e en vir on m en t sh a ll r efer to:
• th e ph ysica l elem en ts of th e E a r th , n a m ely
th e a ir, w a ter, la n d su r fa ce, su b-su r fa ce
str a ta (togeth er w ith a ll livin g r esou r ces
th er ein );
• ou ter spa ce;
• a m bien t ba ck gr ou n d a n d h u m a n h a bita tion s;
• th e wor k pla ce;
• in digen ou s peoples; a n d
• th e n a tu r a l, cu ltu r a l a n d com m on h er ita ge
of th e wor ld.
Wh ile th er e m ay be m a n y con sequ en ces of
en vir on m en ta l de gr a da tion in th e globa l
com m u n ity, on e of th e em er gin g pr in cipa l
con cer n s lies in th e a r ea of h u m a n h ea lth .
Th is pa per is dedica ted to th e r eview of existin g scien tific in vestiga tion s so a s to develop a
gr ea ter u n der sta n din g of h ow en vir on m en ta l
fa ctor s ca n im pa ct n ot on ly on n a tion a l a n d
r e gion a l com m u n ities, bu t a lso on th e in ter n a tion a l com m u n ity a n d a dver sely a ffect th e
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a spir a tion s of h u m a n society for a better
fu tu r e. Th u s, a s th e con flict between m a n a n d
th e en vir on m en t in ten sifi es, it wou ld be w ise
to bea r in m in d th a t th e h u m a n body m ay pay
th e u ltim a te pr ice for th e in discr etion s of th e
h u m a n r a ce.
Environmental degradation and
human health: the global village
Global warming
Clim a te ch a n ge is destin ed to a ffect th e en tir e
globa l villa ge a s it is a pla n eta r y occu r r en ce.
A w a r m er wor ld is for eca st a s a r esu lt of th e
effects of gr een h ou se em ission s. It is n ow
th ou gh t th a t h u m a n h ea lth m ay be a ffected
by globa l w a r m in g. Un der w a r m er con dition s, h ea t str ess r ela ted con dition s m ay
becom e m or e com m on , lea din g to in cr ea ses
in m or bidity a n d m or ta lity (Lon gstr eth , 1990,
p. 525; Sch n eider, 1989, p. 182). Wa r m er su m m er s m ay pr odu ce h igh er in fa n t a n d foeta l
m or ta lity du e to su m m er tim e in cr ea ses in
in fection s (Lon gstr eth , 1990, p. 525). Moister
a n d w a r m er con dition s wou ld fa cilita te th e
n or th w a r d spr ea d of in sect-bor n e disea ses,
for exa m ple, fr om m osqu itoes a n d tick s
(Sch n eider, 1989, p. 182). On e possible disea se
th a t m ay flou r ish u n der con dition s of globa l
w a r m in g is m a la r ia . Addition a lly, w a r m er
a n d m oister con dition s m ay lea d to h igh er
r a tes of sk in in fection s (Lon gstr eth , 1990, p.
525).
Depletion of the stratospheric ozone layer
An oth er en vir on m en ta l pr oblem w ith globa l
con sequ en ces is th e depletion of th e str a tosph er ic ozon e layer, a n d h er e h u m a n h ea lth
m ay ver y well pr ove to be th e m ost dir ect
ca su a lty. E xposu r e to u ltr aviolet-B r a dia tion
ca n ca u se a su ppr ession in im m u n e system s
lea din g to a n in cr ea se in in fection s (Mor ison ,
1992, p. 49). Addition a lly, th er e m ay even be a
possible decr ea se in th e effectiven ess of va ccin es (UN E P, 1990, p. 116). Sk in pigm en ta tion
wou ld n ot pr otect a ga in st deficien cies in th e
im m u n e system , so r en der in g per son s in th e
tr opics equ a lly a t r isk (Ilya s, 1989; J eeva n a n d
Kr ipk e, 1993, p. 1160).
E n h a n ced levels of u ltr aviolet-B r a dia tion
ca n lea d to in cr ea sed da m a ge to th e eyes,
lea din g to a h igh er in ciden ce of ca ta r a cts.
Ca ta r a cts ca n im pa ir vision a n d even ca u se
blin dn ess. It h a s been estim a ted th a t th e
in ciden ce of ca ta r a cts wou ld in cr ea se by 0.6
per cen t per 1 per cen t ozon e depletion . Th is
m ay r esu lt in a n a ddition a l 100,000 ca ses of
blin dn ess wor ldw ide (UN E P, 1990, p. 116).
With r espect to oth er ocu la r a ilm en ts, it is
a n ticipa ted th a t th er e wou ld be a r ise in ca ses
of k er a to-con ju n ctivitis or sn ow blin dn ess.
[ 52 ]
F in a lly, lon g-ter m in cr ea ses in u ltr aviolet-B
ir r a dia n ce w ill en h a n ce th e r isk of n on m ela n om a sk in ca n cer (Ma dr on ich a n d De
Gr u jl, 1994, pp. 541-6). It is pr ojected th a t
ever y 1 per cen t decr ea se in th e tota l ozon e
colu m n w ill r esu lt in a 3 per cen t r ise in th e
in ciden ce of n on -m ela n om a ca n cer (Diffey,
1992, pp. 2267-79; UN E P, 1990, p. 116). Ca ses of
th e m or e da n ger ou s m a lign a n t m ela n om a a r e
a lso a n ticipa ted (Hen r ik sen et a l., 1990, pp.
579-82; J on es, 1989, p. 213). Ultr aviolet-B r a dia tion ca n in cr ea se m or ta lity a n d m or bidity
sign ifica n tly th r ou gh m ela n om a a n d n on m ela n om a sk in ca n cer s. On a less ser iou s
level to sk in ca n cer, u ltr aviolet-B r a dia tion
ca n a lso r esu lt in a cu te er yth em a or su n bu r n ,
a con dition th a t w ill especia lly a fflict ligh t
sk in n ed people (J on es, 1989, p. 208). Th e effect
of ozon e depletion wou ld be to sh ift popu la tion s closer to equ a tor ia l con dition s of u ltr a violet exposu r e th a n gen etica lly per m issible
(J on es, 1989, p. 215). Developin g cou n tr ies
w ith a lr ea dy u n der developed h ea lth -ca r e
system s wou ld su ffer tr em en dou sly if th er e is
a n u psu r ge in in fection r a tes or ca ta r a ct
for m a tion (Tolba a n d E l-Kh oly, 1993, p. 34).
M arine resource
Th e th r ea t to th e ocea n s by pollu tion is ca pa ble of cr ea tin g h avoc th r ou gh ou t th e wor ld.
Pollu tion of ocea n s or igin a tes fr om m a n y
sou r ces. Today over 60 per cen t of th e wor ld’s
popu la tion live w ith in th e vicin ity of a coa stlin e, w ith two-th ir ds of th e wor ld’s cities w ith
popu la tion s of m or e th a n 2.5 m illion situ a ted
n ea r estu a r ies (Tolba a n d E l-Kh oly, 1993,
p. 107). Th is h igh level of popu la tion in th e
vicin ity of ocea n s h a s led to th e dir ect du m pin g of m u n icipa l w a stes a t sea , wh er e ver y
often liqu id a n d sem i-solid w a stes a r e sim ply
pu m ped th r ou gh sh or t pipes (Wh ite, 1993,
p. 87). Addition a lly, m a n ’s u se of th e ocea n s
h a s led to pollu tion fr om w ith in th e ocea n . It
is estim a ted th a t a ppr oxim a tely 6.4 m illion
ton s of gen er a l sh ipboa r d litter a r e du m ped
a n n u a lly by sh ips a t sea (Tolba a n d E l-Kh oly,
1993, p. 120). F u r th er, ocea n u ser s m a in ly
involved in th e fish in g in du str y gen er a te
136,000 ton s of pla stic, n ets, lin es a n d bu oys
a n d 22,000 ton s of pla stic con ta in er s, a ll of
wh ich con tr ibu te to litter in g of th e ocea n
(Wh ite, 1993, p. 85).
Hydr oca r bon pollu tion is on e of th e best
k n ow n sou r ces of ocea n con ta m in a tion . Yet
su r pr isin gly, specta cu la r oil ta n k er spilla ges
con tr ibu te a m er e 22 per cen t to th e h ydr oca r bon pollu tion of ocea n s. An over wh elm in g 59
per cen t com es fr om th e r ou tin e flu sh in g of
oil ta n k er h olds. Ra dioa ctive w a ste is a lso a
con tr ibu tor to pollu tion of ocea n s a s th ese
ecosystem s wer e con sider ed du m ps of la st
r esor t. In som e in sta n ces solid m u n icipa l
w a ste a n d even h a za r dou s w a ste a r e sim ply
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tr a n spor ted ou t in to th e sea a n d du m ped.
In r ecen t tim es, h a za r dou s w a ste w a s tr a n spor ted to sea a n d in cin er a ted. Ash es a n d
oth er con ta m in a n ts th a t a r e n ot effectively
n eu tr a lized by in cin er a tion a r e du m ped a t
sea (Wh ite, 1993, pp. 86-7). F in a lly, offsh or e
m in in g a ctivities h ave con tr ibu ted to th e
pollu tion of th e ocea n s. In Th a ila n d it h a s
been discover ed th a t offsh or e tin m in in g h a s
de gr a ded sea w a ter qu a lity a n d da m a ged r eef
ecosystem s (Ru ya bh or n a n d P h a n tu m va n it,
1988, p. 229).
By fa r th e gr ea test h ea lth th r ea t fr om pollu tion of th e wor ld’s ocea n s com es fr om fi sh
con ta m in a tion . Th e Un ited N a tion s E n vir on m en ta l P r ogr a m m e (UN E P ) h a s estim a ted
th a t over 20 billion ton s of w a ste in clu din g
sew a ge, a gr icu ltu r a l r u n -off a n d in du str ia l
w a ste a r e du m ped in to th e ocea n a n n u a lly.
Appr oxim a tely 90 per cen t r em a in n ea r coa stlin es wh ich , togeth er w ith r eefs pr ovide
a r ou n d 95 per cen t of th e wor ld’s fi sh ca tch
(Tolba a n d E l-Kh oly, 1993, p. 117; Wh ite, 1993,
p. 87). F ish con ta m in a tion ca n h ave ser iou s
h ea lth im plica tion s. Th e con su m ption of
con ta m in a ted sea food ca n lea d to ser iou s
h ea lth pr oblem s, pa r ticu la r ly in developin g
cou n tr ies wh er e, a s n oted befor e, th e ocea n s
pr ovide th e m a jor sou r ce of pr otein . Th e
Min im a ta m er cu r y poison in g in ciden t in
J a pa n is a n exa m ple of th e a dver se con sequ en ces of con su m in g con ta m in a ted sea food
(Wh ite, 1993, pp. 85-6). In Min im a ta m er cu r y
w a ste pr odu ced by a loca l in du str y w a s
pou r ed in to th e sea to en ter th e h u m a n food
ch a in th r ou gh con ta m in a ted sea food. Th e
r esu lt w a s th e on set of debilita tin g h u m a n
illn esses a ssocia ted w ith m er cu r y poison in g.
Chemicals
Th er e a r e cer ta in a r ea s of envir on m en ta l
de gr a da tion th a t a lth ou gh ta k in g pla ce
w ith in n a tion a l bou n da r ies a r e so
w idespr ea d a s to ju stify globa l con cer n . On e
su ch a r ea is ch em ica l pollu tion . F r om tim e
im m em or ia l, m a n h a s en ga ged in th e m a n u fa ctu r e of ch em ica ls. Th ese pr odu cts a r e u sed
on ou r bodies, in ou r h om es, fi elds, food,
tr a n spor t a n d in deed in a lm ost ever y a spect
of ou r life. It h a s been ca lcu la ted th a t between
1956 a n d 1982, over 4 m illion distin ct ch em ica l
com pou n ds wer e for m u la ted w ith a s m a n y a s
6,000 n ew for m u la tion s bein g cr ea ted week ly
sin ce. Wilson (1993) sta tes th a t a ppr oxim a tely
3,000 ch em ica ls a r e deliber a tely a dded to
food, 700 h ave been fou n d in dr in k in g w a ter,
a bou t 400 h ave been iden tified in h u m a n tissu es a n d over 500 cou ld be fou n d u n der th e
k itch en sin k or in th e la u n dr y r oom of th e
aver a ge h ou se. Th e fa ct th a t over 70,000 ch em ica ls a r e in da ily u se cr ea tes a ca u se for con cer n especia lly w ith r e ga r d to issu es of h ea lth
a n d sa fety (p. 1).
Pesticides a r e pr oba bly th e m ost
w idespr ea d a n d in fa m ou s sou r ce of ch em ica l
con ta m in a tion wh ich exists in th e a tm osph er e, w a ter, soil a n d food. Th e wor ld wok e
u p to th e h or r or s of th e in discr im in a te u se of
pesticides w ith th e pu blica tion of th e fa m ou s
S ilen t S pr in g by Ra ch el Ca r son (1991). Th e
w idespr ea d u se of pesticides is a fea tu r e of
th e twen tieth cen tu r y, th e m a n ifesta tion of
a n oth er tool to a sser t con tr ol over n a tu r e.
Th e r ise of pesticides is in tim a tely lin k ed
w ith th e discover y in 1939 of th e in secticida l
ca pa bilities of dich lor o-diph en yl-tr ich lor oeth a n e (DDT) (McE wen a n d Steph en son , 1979
pp. 2-4). F r om th a t poin t on w a r ds pesticides
h ave played a n im por ta n t r ole in h u m a n
society. Th ey h ave been u sed for a m yr ia d
ca u ses, su ch a s th e con tr ollin g of pests,
en h a n cem en t of cr ops, destr u ction of disea seca u sin g in sects a n d im pr ovem en t of h ou seh old con dition s by er a dica tin g th ose livin g
or ga n ism s th a t h ave led to discom for t in
dwellin g pla ces (McE wen a n d Steph en son ,
1979, pp. 8-19).
T h e a dver se effect s of ch em ica ls on h u m a n
h ea lt h is by fa r t h e m ost im por t a n t a r ea of
con cer n . Ch em ica l con t a m in a t ion ca n en t er
t h e or ga n s of livin g t h in gs t h r ou gh a ir, w a t er
a n d food. Sim ple in h a la t ion of con t a m in a t ed
a ir ca n in du ce a dver se r ea ct ion s in t h e
h u m a n body. Food is a n im por t a n t sou r ce of
ch em ica l con t a m in a t ion t h a t fa cilit a t es t h e
in gr ess of h a r m fu l ch em ica ls in t o livin g
t h in gs. Con t a m in a n t s ca n be a cqu ir ed a t t h e
pr odu ct ion , h a r vest in g, pr ocessin g, pa ck a gin g, t r a n spor t , st or a ge, cook in g a n d ser vin g
st a ges. T h e a pplica t ion of pest icides a n d
pr eser va t ives con t a m in a t es food beca u se of
t h e per sist en ce of ch em ica l r esidu es. N or m a l
levels of a ir bor n e ch em ica l con t a m in a n t s
ca n con t r ibu t e t o con t a m in a t ion of food bu t
t h e r esu lt m ay n ot n ecessa r ily be a cu t e t oxicit y. Wa t er ca n con t a m in a t e food in sever a l
w ays. Con su m pt ion of fi sh a n d sh ellfi sh con t a in in g ch em ica l con t a m in a n t s pr ovides a
pa t h w ay for ch em ica ls t o en t er in t o t h e
h u m a n body. Con su m pt ion of ve get a ble pr odu ct s t h a t m ay h ave been cu lt iva t ed w it h con t a m in a t ed ir r iga t ed w a t er is a n ot h er sign ifi ca n t pa t h w ay. E ven t h e con su m pt ion of livest ock wh ich m ay h ave dr u n k con t a m in a t ed
w a t er is a possible con du it for t h e t r a n sfer of
ch em ica l con t a m in a t ion (Lippm a n n a n d
Sch lesin ger, 1979, pp. 24-7). Addit ion a lly, t h e
dr in k in g of ch em ica lly t a in t ed w a t er is a lso a
pr edict a ble w ay of becom in g exposed t o t h e
h a r m fu l effect s of ch em ica ls (McE w en a n d
St e ph en son , 1979, pp. 280-1). F in a lly,
con su m pt ion of cr ops gr ow n on ch em ica lly
t a in t ed soils r e pr esen t s a n ot h er possible
en t r y poin t for ch em ica l con t a m in a n t s in t o
t h e h u m a n body.
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[ 54 ]
In th e m a jor ity of ca ses exposu r e is via
in h a la tion bu t it ca n a lso r esu lt fr om exposu r e of th e sk in (Lippm a n n a n d Sch lesin ger,
1979, p. 51). Th e r espir a tor y tr a ct is th e m a in
poin t of en tr y in to h u m a n s for a ir bor n e
ch em ica ls. Ch em ica ls wh ich a r e w a ter bor n e
or tr a n spor ted in food r ea ch m a n th r ou gh th e
ga str oin testin a l tr a ct. Th ese ca n a lso be
a bsor bed in to th e h u m a n body th r ou gh th e
sk in . Th e r a n ge of biologica l r espon ses to
ch em ica l con ta m in a n ts in th e body is qu ite
diver se a n d m ay r a n ge fr om ir r ita n t, fibr otic,
a sph yxia n t, a ller gic to ca r cin ogen ic (Lippm a n n a n d Sch lesin ger, 1979, pp. 194-214). It
h a s been estim a ted th a t th r ee ou t of ever y ten
people in th e USA ca n expect to con tr a ct
som e for m of ca n cer, a n d in a ppr oxim a tely 98
per cen t of th e ca ses th ese m ay be lin k ed to
ch em ica l exposu r e. In a ddition to ca n cer,
ch em ica l exposu r e is r espon sible for a m yr ia d oth er h ea lth pr oblem s r a n gin g fr om n eu r ologica l, im m u n ologica l a n d developm en ta l
to r epr odu ction (Wilson , 1993, pp. 2-4). Wilson
pr ovides on e of th e m ost com pr eh en sive tr ea tises on th e h ea lth im plica tion s of va r iou s
ch em ica ls. Th e list of h u n dr eds of lik ely a ilm en ts fr om ch em ica l exposu r e is a ch illin g
r em in der of h u m a n vu ln er a bility (Wilson ,
1993, pp. 11-72). With ou t dou bt, exposu r e to
h a r m fu l ch em ica ls ca n in cr ea se m or ta lity
a n d m or bidity (Bla in , 1990). Most ca ses of
w idespr ea d m or ta lity a r e th e r esu lt of in du str ia l a cciden ts a n d spilla ge of ch em ica ls a s
occu r r ed in Bh opa l, in In dia . However,
a lth ou gh dea th s h ave occu r r ed th r ou gh less
specta cu la r m edia , th er e a r e m u ch fewer da ta
ava ila ble in ca ses wh er e th e exposu r e m ay
h ave been a lon g-ter m pr oblem (Lippm a n n
a n d Sch lesin ger, 1979, pp. 53-4).
Th e occu pa tion a l en vir on m en t is a n oth er
m a jor sou r ce of exposu r e to h a r m fu l ch em ica ls a m on g h u m a n s a n d m er its specia l m en tion . It h a s been a sser ted th a t m ost ca ses of
ch em ica l poison in g h ave a r isen fr om occu pa tion a l exposu r e. Mor e th a n ever, ch em ica l
pr odu ction is sh iftin g to developin g cou n tr ies
wh er e th e r e gu la tor y fr a m ewor k is less
sever e th a n in developed cou n tr ies. Th e
r esu lt h a s been a r ise in ca ses of ch em ica l
poison in g a lth ou gh th er e is sign ifi ca n t u n der r epor tin g a n d la ck of r esea r ch in th is a r ea .
Va r iou s stu dies, h owever, h ave led to r ea son a ble estim a tes of th e m a gn itu de of th e pr oblem . In Ta iw a n it w a s discover ed th a t em ployees in a pla n t en ga ged in th e m a n u fa ctu r e of
pesticides h a d su bsta n tia lly decr ea sed
pla sm a ch olin ester a se (Wu , 1989, pp. 661-3).
N ot on ly th ose wh o m a n u fa ctu r e th e pesticides a r e a ffected bu t wor k er s wh o a r e
en ga ged in a dm in ister in g th e ch em ica ls a r e
equ a lly, if n ot m or e, a t r isk . A stu dy in In dia
r evea led a pr eva len ce of r espir a tor y a ilm en ts
a m on g spr ayer s in m a n go pla n ta tion s. Th e
spr ayer s, beca u se of a n a bsen ce of pr oper
sa fety equ ipm en t, wer e dir ectly exposed to
th e pesticides th r ou gh sk in con ta ct a n d r espir a tion a n d in dir ectly th r ou gh food con su m ption (Ra stogi, 1989). Th e pr oblem of im pr oper
pr otection of wor k er s u sin g pesticides h a s
given r ise to wh a t h a s been descr ibed a s a n
epidem ic of pesticide poison in g in N ica r a gu a
(McCon n ell a n d Hr u sk a , 1993).
Th e exa m ples n oted a bove in th e ca se of
wor k er s dea lin g w ith h a r m fu l ch em ica ls a r e
n ot isola ted bu t in dica tive of a m u ch br oa der
pr oblem a n d pesticide poison in g h a s em er ged
a s a m a jor con cer n . WHO a n d UN E P h ave
estim a ted th a t over on e m illion ca ses of pesticide poison in g occu r yea r ly, w ith a r ou n d
20,000 fa ta lities (P im en tel et a l., 1992, p. 750).
A m or e r ecen t stu dy h a s su ggested th a t th e
in ciden ts of pesticide poison in g m ay be a s
h igh a s th r ee m illion a n n u a lly (McCon n ell
a n d Hr u sk a , 1993, p. 1559). In spite of th e
developed cou n tr ies u sin g a r ou n d 80 per cen t
of th e pesticides pr odu ced in th e wor ld, it h a s
been estim a ted th a t 99 per cen t of pesticide
fa ta lities occu r in th e developin g wor ld, w ith
ju st a s sign ifica n t a per cen ta ge in th e a r ea of
n on -fa ta l poison in gs. An oth er a r ea of con cer n in th e developin g wor ld is th e h igh level
of per in a ta l m or ta lity. It h a s been estim a ted
th a t th er e a r e a bou t seven m illion per in a ta l
dea th s per a n n u m in developin g cou n tr ies. A
stu dy in Su da n h a s in dica ted a con sisten t a n d
sta tistica lly sign ifica n t r ela tion sh ip between
exposu r e to pesticides a n d th e in cr ea sed r isk
of still bir th or per in a ta l dea th (Ta h a a n d
Gr ay, 1993, pp. 319-20).
Nuclear operations
N u clea r oper a tion s a r e n a tion a l a ctivities
w ith globa l im plica tion s. Th e biggest fea r
per ta in in g to n u clea r a ctivities a r ises fr om
th e possibility of th e u se of n u clea r tech n ology a s a wea pon a n d n u clea r a cciden ts. Th e
ter r estr ia l en vir on m en t ca n becom e a ffected
by r a dion u clides em itted or disch a r ged eith er
a cciden ta lly or deliber a tely fr om a ser ies of
pa th w ays. Th er e ca n be dir ect deposition of
con ta m in a ted soils by fl oodin g or ir r iga tion
w ith con ta m in a ted w a ter, or a er ia l wet or dr y
deposition . Accor din gly, ter r estr ia l ve geta tion m ay becom e con ta m in a ted a s a r esu lt of
dir ect deposition or r a dion u clides en ter in g
fr om th e soil (Pen tr ea th , 1980, p. 173). Som e
em ission s lik e iodin e-131 a fter deposition on
folia ge ca n be dir ectly in gested fr om a ffected
fr u its a n d ve geta tion or th r ou gh th e cow m ilk -m a n pa th w ay (Pen tr ea th , 1980, pp. 146-7).
Th u s, m a n m ay be a ffected by r a dioa ctive
em ission s th r ou gh con su m ption of fr u its a n d
ve geta tion , cow ’s m ilk or m ea t fr om a n im a ls
th a t m ay h ave con su m ed con ta m in a ted
ve geta tion (Pen tr ea th , 1980, pp. 180-1). Th e
disch a r ge of liqu id efflu en ts in th e a qu a tic
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envir on m en t ca n a lso fin d its w ay in to th e
h u m a n body eith er by dr in k in g a ffected w ater
or con su m ption of fish a n d oth er a qu a tic
sou r ces of h u m a n food th a t m ay h ave been
con ta m in a ted (Pen tr ea th , 1980, pp. 158-65).
A da n ger ou s th r ea t to h u m a n h ea lth a r isin g fr om th e u se of n u clea r tech n ology is th e
possibility of exposu r e to r a dia tion . In ju r y to
livin g or ga n ism s a r ises fr om da m a ge to cells
in th e body. High levels of r a dia tion lea d to
both som a tic a n d gen etic ch a n ges in livin g
or ga n ism s. Som a tic effects a r e th ose r esu ltin g dir ectly fr om th e r a dia tion dose r eceived
by th e a ffected cells a n d m a n ifest th em selves
in som e for m of r a dia tion -in du ced m a lign a n cy (E ich h olz, 1977, p. 121). Th e effects
in clu de in cr ea sed in ciden ce of leu k a em ia a n d
oth er types of ca n cer, in clu din g tu m ou r s of
th e th yr oid gla n d, lu n g, a n d th e br ea st in
wom en . High er in ciden ce of bon e ca n cer h a s
a lso been obser ved in som e in sta n ces (Gla sston e a n d J or da n , 1980, pp. 184-91). Gen etic
effects a r ise wh en th e r epr odu ctive cells a r e
ir r a dia ted, r esu ltin g in ch a n ges in th e gen es
or ch r om osom es of th ese cells, a n d th e su bsequ en t h a n din g dow n of th ese ch a n ges to
descen da n ts of th e a ffected in dividu a l. Th er e
a r e differ en t types of gen etic ch a n ges,
n a m ely, gen e m u ta tion s, ch r om osom e a ber r a tion s, a n d ch a n ges in th e n u m ber of ch r om osom es. Th ese ch a n ges ca n r esu lt in th e pr esen ce of a bn or m a lities in offspr in g r a n gin g
fr om leth a l to m ildly detr im en ta l (E ich h olz,
1977, p. 123).
Environmental degradation and
human health: the regional
connection
Freshwater
Wa ter is th e essen ce of life, w ith ou t wh ich
m a n ’s existen ce ca n be tr a n sfor m ed in to on e
con tin u ou s litu r gy of su ffer in g. Th is is cu r r en tly eviden t in pla ces lik e th e Sa h el r e gion .
However, in a ddition to w a ter ava ila bility,
w a ter qu a lity a lso poses a pr oblem , pa r ticu la r ly in developin g cou n tr ies. It m ay be a ccu r a te to sta te th a t th e n eed for a sa fe dom estic
w a ter su pply is per h a ps th e gr ea test th r ea t to
th e developin g wor ld (Witt, 1982, p. 301).
Wh er e w a ter su pply is low a n d w a ter tr ea tm en t in efficien t, h u m a n h ea lth is a t its m ost
vu ln er a ble poin t (Fea ch em , 1983). Th e con cer n in m a n y developin g cou n tr ies focu ses on
a su pply of sa fe a n d a dequ a te a m ou n ts of
w a ter for con su m ption a n d sa n ita r y
pu r poses. Th e Un ited N a tion s Developm en t
P r ogr a m m e (UN DP ) h a s estim a ted th a t
du r in g th e per iod 1988-1991, 70 per cen t of th e
developin g wor ld h a d a ccess to sa fe w a ter,
w ith th e figu r e dr oppin g to 45 per cen t for th e
lea st developed cou n tr ies. With r espect to
sa n ita tion fa cilities, 56 per cen t h a d a ccess
w ith a m er e 32 per cen t for th e lea st developed
cou n tr ies (UN DP, 1994, Ta ble 2, p. 132). Th ese
figu r es tr a n sla ted in 1992 to a ppr oxim a tely 1.3
billion people w ith ou t a ccess to sa fe w a ter
a n d 1.9 billion w ith ou t a ccess to pr oper sa n ita tion fa cilities (UN DP, 1994, Ta ble 3, p. 135).
Th e h ea lth im plica tion s flow in g fr om th e
fa ilu r e to su pply w a ter of su fficien t qu a lity
for dom estic u sa ge a r e tr em en dou s in developin g cou n tr ies. In a ddition to th e dir ect
th r ea ts th a t m ay flow fr om con su m ption of
w a ter con ta m in a ted by pollu ta n ts su ch a s
ch em ica l a gen ts, th e gr ea test ca u se of m or ta lity a n d m or bidity is th e spr ea d of in fectiou s
disea ses. In th e developin g wor ld th ese
a ccou n t for 72 per cen t of th e dea th s of a ll
ch ildr en u n der five yea r s old a n d 45 per cen t
of dea th s over a ll. Th e pr eva len ce of in fectiou s disea ses is dir ectly a ttr ibu ta ble to m a ln u tr ition , in a dequ a te w a ter su pply, la ck of
sa n ita tion fa cilities, poor h ygien ic pr a ctices
a n d u n sa tisfa ctor y livin g con dition s (UN E P,
1993, p. 235).
Th er e a r e five m a jor pa th w ays for w a ter r ela ted disea ses to be tr a n sm itted to h u m a n s.
F ir st, th er e a r e w a ter -bor n e disea ses wh ich
ca n a r ise fr om m u ltiple ca u ses, su ch a s th e
pr esen ce of h u m a n or a n im a l fa eces in w a ter,
u r in e in fected by ba cter ia a n d pa th ogen ic
vir u ses. Th ese or ga n ism s a r e tr a n sm itted to
h u m a n s wh en th e w a ter is u sed for dr in k in g
or food pr epa r a tion (UN E P, 1993, p. 235).
E xa m ples of w a ter -bor n e disea ses a r e
poliom yelitis, a sca r ia sis, en ter ic fever a n d
dia r r h oea l disea ses. In th e la te 1980s th er e
wer e a ppr oxim a tely th r ee billion ca ses of
th ese disea ses, pr im a r ily in th e developin g
wor ld w ith over 4.07 m illion fa ta lities, w ith
dia r r h oea l disea ses su ch a s ch oler a a n d
typh oid a ccou n tin g for fou r m illion dea th s
(UN E P, 1993, Ta ble 5.6, p. 256).
Wa ter -w a sh ed disea ses a r e ca u sed by th e
sca r city of w a ter, wh ich r en der s clea n lin ess
difficu lt to a tta in . Th is ca te gor y in clu des a ll
w a ter -bor n e disea ses in a ddition to in festa tion w ith lice or m ites wh ich a r e vector s of
typh u s (N a sh , 1993, p. 26). Com m on types of
w a ter -w a sh ed a ffliction s a r e tr a ch om a a n d
leish m a n ia sis. In th e la te 1980s th ese con dition s a ffected u p to 21 m illion people in th e
developin g wor ld a n d in th e ca se of tr a ch om a
r en der ed between six a n d n in e m illion people
blin d (UN E P, 1993, Ta ble 5.6, p. 256).
Wa ter -ba sed disea ses a r e th ose in wh ich
w a ter pr ovides th e h a bita t for th e im m edia te
h ost or ga n ism s in wh ich cer ta in pa r a sites
pa ss pa r t of th eir life cycle (N a sh , 1993, p. 26).
Th e h ost or ga n ism m ay be in gested du r in g
con su m ption of fish or oth er fr esh w a ter food
or th e dr in k in g of in fected w a ter. E xa m ples of
w a ter -ba sed con dition s a r e sch istosom ia sis
a n d dr a cu n cu lia sis wh ich a ffected a r ou n d
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210 m illion people in th e developin g wor ld in
th e la te 1980s. Du r in g th is per iod, sch istosom ia sis r esu lted in a ppr oxim a tely 200, 000
fa ta lities (UN E P, 1993, Ta ble 5.6, p. 256).
Wa ter -r ela ted disea ses a r e th ose in wh ich
in sect vector s of pa r a sitic disea ses r ely on
w a ter a s a h a bita t. In th is ca se tr a n sm ission
is n ot du e to dir ect h u m a n con ta ct w ith w a ter
(UN E P, 1993, p. 235). Afr ica n tr ypa n osom ia sis,
eleph a n tia sis, on ch ocer cia sis, yellow fever,
den gu e fever, J a pa n ese en ceph a litis a n d
m a la r ia dom in a te th is a r ea a ccou n tin g for
435.04 m illion ca ses in th e developin g wor ld
in th e 1980s w ith fa ta lities r a n gin g between
on e a n d 2.05 m illion . Ma la r ia a ccou n ted for
th e bu lk of th e ca ses w ith 267 m illion a n d
between on e a n d two m illion of th e r ecor ded
dea th s (UN E P, 1993, Ta ble 5.6, p. 256).
F in a lly, th er e a r e w a ter -disper sed in fection s wh er e th e in fectiou s a gen ts th r ive in
fr esh w a ter a n d a r e in h a led in to th e r espir a tor y tr a ct w ith m in u te w a ter dr oplets.
L egion ella is a n exa m ple of a w a ter -disper sed
in fection a n d th is ca te gor y of w a ter -r ela ted
disea ses is th e on ly on e th a t a ppea r s w ith
som e fr equ en cy in developed cou n tr ies
(UN E P, 1993, p. 235).
Th e sta r tlin g sta tistics of w a ter -ba sed disea ses r ecited a bove a r e per h a ps th e tr a gic
pr oof th a t th e gr ea test th r ea t to developin g
cou n tr ies lies in obta in in g a fr esh w a ter su pply for dom estic u sa ge. With ou t u r gen t a tten tion to th is r equ ir em en t, th e lives of billion s
m ay be sim ply w a sted aw ay.
Desertification
On e of th e a la r m in g fea tu r es of th e la st two
deca des h a s been th e gr ow in g deser tifica tion
of sever a l r e gion s in th e developin g wor ld, th e
m ost n oticea ble bein g th e Su b-Sa h a r a n
r e gion . Wh ile th e loss of biologica l diver sity
a n d h u m a n su ffer in g a r e th e m ost a ppa r en t
m a n ifesta tion s of deser tifica tion , th er e m ay
even be h ea lth con sequ en ces. Cr op fa ilu r e
a n d loss of livestock often lea ds to m a ln u tr ition . Wea k en ed bodies a r e th en r en der ed
su sceptible to th e r ava ges of h u n ger a n d disea se. Alth ou gh few disea ses a r e specific to
deser tifica tion , eye disea se su ch a s tr a ch om a
a n d oth er a ffliction s lik e bilh a r zia m ay be
m or e pr om in en t u n der con dition s of deser tifica tion (Secr eta r ia t of th e Un ited N a tion s
Con fer en ce on Deser tifica tion , 1977, p. 42).
Environmental degradation and
human health: national risk
Indoor air pollution
Th er e a r e a r ea s of en vir on m en ta l a bu se th a t
give r ise pr edom in a n tly to n a tion a l h ea lth
pr oblem s. On e su ch a r ea is in door a ir pollu tion wh ich h a s r ava ged th e developin g wor ld
[ 56 ]
w ith a n estim a ted 400 to 700 m illion people
bein g a t r isk a n d a n n u a l dea th s to in fa n ts a n d
ch ildr en of a r ou n d fou r m illion a n n u a lly
(Wor ld Ba n k , 1992, p. 52). Th e m a jor pr oblem s
a r e ca u sed by n on -biom a ss a n d biom a ss com bu stion . N on -biom a ss in door com bu stion
n or m a lly per ta in s to th e u se of ga s r a n ges for
cook in g. Gen er a lly, in door ga s r a n ges do n ot
h ave a ga s exh a u st system , so a llow in g th e
ga seou s pr odu cts of com bu stion to en ter th e
in door a ir dir ectly du r in g u se (Gr eim , 1989,
p. 193). Th e two m a jor em ission s a r e ca r bon
m on oxide a n d n itr ogen dioxide.
Ca r bon m on oxide is em itted a s a r esu lt of
th e in com plete com bu stion of ca r bon a ceou s
m a ter ia l. In a ddition to ga s r a n ges, w a ter
h ea ter s a n d ga s or coa l h ea ter s a r e m a jor
in door sou r ces of ca r bon m on oxide. Ca r bon
m on oxide pr odu ces toxic effects in th e
h u m a n body. Du e to its a ffin ity to h a em oglobin it displa ces oxygen , so lower in g th e oxygen ca r r yin g ca pa city of blood. Ca r bon
m on oxide h a s its m ost toxic a cu te effects on
th e or ga n s w ith h igh oxygen r equ ir em en ts,
su ch a s th e h ea r t a n d th e br a in . At low levels,
ca r bon m on oxide ca n ca u se fl u -lik e sym ptom s especia lly in ch ildr en (Gold, 1992, pp.
216-7). At h igh levels, it ca n lea d to com a a n d
possibly dea th (Wellbu r n , 1988, p. 17). N itr ogen dioxide is a n oxida n t th a t is solu ble in
tissu es. Most in h a led n itr ogen dioxide is
r eta in ed in th e lu n gs a n d deposited pr im a r ily
in th e la r ge a n d sm a ll a ir w ays. At h igh con cen tr a tion s n itr ogen dioxide ca u ses exten sive
lu n g in ju r ies. F a ta l pu lm on a r y oedem a a n d
br on ch opn eu m on ia h ave been r epor ted a t
h igh con cen tr a tion s, w ith br on ch itis a n d
pn eu m on ia a t lower levels (La m ber t a n d
Sa m et, 1994, p. 612).
Biom a ss fu els com pr ise pr ocessed biom a ss
su ch a s ch a r coa l, m eth a n e, loggin g w a ste a n d
saw du st. Un pr ocessed biom a ss fu els a r e gen er a ted fr om sou r ces su ch a s wood, du n g,
str aw, a gr icu ltu r a l w a stes a n d ve geta ble
m a tter. Bu r n in g of biom a ss for fu el ca n r esu lt
in th e pr odu ction of pa r ticu la tes,
ben zo(a )pyr en e, ca r bon m on oxide, n itr ogen
dioxide, su lph u r dioxide, for m a ldeh yde,
vola tile or ga n ic com pou n ds a n d n u m er ou s
oth er su bsta n ces (Gold, 1992, p. 218). In th is
a r ea th e developin g wor ld a ppea r s m ost vu ln er a ble. Un for tu n a tely, except for th e wor k of
Ch en (1990), th e issu e h a s n ot been com pr eh en sively r esea r ch ed in th e developin g wor ld.
It h a s been sta ted th a t in door pollu ta n ts
m ay pose a gr ea ter h ea lth r isk in th e developin g wor ld th a n ou tdoor a ir pollu tion du e to
th e fa ct th a t m a n y people, especia lly wom en ,
spen d a lot of tim e in door s (Davidson , 1986,
p. 561). Biom a ss su pplies 14 per cen t of th e
wor ld’s pr im a r y en er gy, w ith th e developin g
wor ld a ccou n tin g for a ppr oxim a tely 35 per
cen t of th a t fi gu r e. In som e developin g
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cou n tr ies, biom a ss a ccou n ts for a s m u ch a s 90
per cen t of th e pr im a r y en er gy. Appr oxim a tely
50 per cen t of th e wor ld’s popu la tion pr edom in a n tly fr om th e developin g wor ld, r ely m a in ly
or exclu sively on biom a ss fu els to sa tisfy th eir
da ily en er gy n eeds, th a t is, for cook in g a n d
h ea tin g (UNEP, 1993, p. 273).
In developin g cou n tr ies, it h a s been sh ow n
th a t th e in ciden ce of lu n g ca n cer r ises a s a
r esu lt of exposu r e to pa r ticu la tes a n d ga seou s
em ission a r isin g fr om bu r n in g of biom a ss
fu el in wh a t a r e often poor ly ven tila ted
h ou ses. Addition a lly, th er e is a h igh er in ciden ce of ch r on ic br on ch itis in n on -sm ok in g
wom en , a n d r espir a tor y a ilm en ts a n d pn eu m on ia a m on g ch ildr en (Gold, 1992, p. 218).
Th ese tr en ds h ave been bor n e ou t in th e
in cr ea sin g n u m ber of ca se stu dies per for m ed
in developin g cou n tr ies, pa r ticu la r ly in
Afr ica a n d Asia . E xposu r e to ga seou s em ission s fr om biom a ss bu r n in g h a s been lin k ed
w ith dim in ish ed lu n g fu n ction s in ch ildr en in
Ku a la Lu m pu r, Ma laysia (Azizi a n d Hen r y,
1990, p. 26). In a ca se con tr ol stu dy per for m ed
in th e pr ovin ce of Gu a n gzh ou , Ch in a , lu n g
ca n cer em er ged a s th e m a jor ca u se of dea th
by ca n cer a m on g m en a n d wom en . Sm ok in g
a ppea r ed to be dom in a n t a m on g m a le fa ta lities bu t w ith r espect to wom en cou ld n ot h ave
been a sign ifi ca n t fa ctor, beca u se of lower
sm ok in g a ctivities. Th e r esu lts of th e stu dy
in dica ted th a t in door a ir pollu tion du e to
h om e cook in g w a s th e dr ivin g fa ctor in lu n g
ca n cer a m on g wom en wh o wer e exposed to
coa l fu m es a n d cook in g oil va pou r s (Liu et a l.,
1993). In Sh en ya n g, Ch in a , a ca se con tr ol
stu dy of 1,249 pa tien ts w ith lu n g ca n cer fou n d
th a t wh ile ciga r ette sm ok in g w a s a m a jor
con tr ibu tor y fa ctor, in door a ir pollu tion w a s
th e sign ifica n t fa ctor in th e ca se of wom en .
Th e r isk of lu n g ca n cer w a s between 50 to 70
per cen t h igh er in h om es h ea ted by coa ls or
u sin g coa ls for cook in g. Wh er e k a n g w a s u sed
for h ea tin g bedr oom s or cook in g w a s don e
w ith in close pr oxim ity of sleepin g qu a r ter s,
th e r isk w a s a t its h igh est level (Xu , 1989). In
Sh a n gh a i, th e in door bu r n in g of coa l h a s
been positively lin k ed to a h igh er in ciden ce of
str ok e a m on g m a les (Zh a n g, 1988, p. 976).
Th e gr im pictu r e in Asia exten ds to Afr ica
wh er e sim ila r r esu lts wer e obta in ed. In Zim ba bwe, in vestiga tion s h ave r evea led th a t
ch ildr en a r e m or e lik ely to su ffer fr om pn eu m on ia in h om es wh er e wood is u sed a s fu el
(L a n cet, 1992, p. 397). In r u r a l Ken ya , m ea su r em en ts of in door a ir pollu tion r evea led th a t
r espir a ble pa r ticu la tes a n d n itr ogen oxide
wer e a ppr oxim a tely ten tim es h igh er th a n th e
r ecom m en ded a ir qu a lity gu idelin es. Addition a lly, th e level of polycyclic a r om a tic
h ydr oca r bon s w a s a lso qu ite h igh (Boleij et
a l., 1989, p. 1677). A stu dy in Gh a n a h a s n oted
th e a dver se h ea lth effects on wom en a n d
you n g ch ildr en a r isin g fr om th e bu r n in g of
biom a ss fu el for cook in g. A pleth or a of r espir a tor y pr oblem s bea r s w itn ess to th e tr a gedy
of in door a ir pollu tion (McGr a n a h a n a n d
Son gsor e, 1994, pp. 4-45).
P a n dey et a l. (1989) h ave n oted th a t, in th e
developin g wor ld, th e exposu r e to h igh levels
of sm ok e fr om in door biom a ss bu r n in g w ith ou t a fl u e or ch im n ey a n d w ith poor ven tila tion is r espon sible for a cu te r espir a tor y in fection s th a t ca u se on e-th ir d of a ll ch ildh ood
dea th s u n der five yea r s. F u r th er, th e ba sic
eviden ce su ggests th a t pea k a n d da ily exposu r es to in door pa r ticu la te levels wou ld
a ppea r a t tim es to be 20 tim es gr ea ter in th e
developin g wor ld th a n th e developed (P a n dey
et a l., 1989, p. 427). On e stu dy h a s r evea led th a t
in selected developin g cou n tr ies, th e aver a ge
a n n u a l m icr ogr a m s of pollu ta n t is 300 per
cu bic m etr e of a ir in r u r a l a r ea s, w ith th e
cor r espon din g fi gu r e for th e developed wor ld
bein g 75 per cu bic m etr e of a ir (Sm ith , 1988,
p. 19).
Outdoor air pollution
Ou tdoor a ir pollu tion is a n oth er ser iou s en vir on m en ta l fa ctor th a t ca n im pa ct a dver sely
on h u m a n h ea lth . Alth ou gh it is dea lt w ith a s
a n a tion a l pr oblem , it ca n qu ite ea sily pose
tr a n sbou n da r y pr oblem s, especia lly in a r ea s
of con cen tr a ted a ir pollu tion , su ch a s th e
Bla ck Tr ia n gle in E u r ope between Ger m a n y,
Pola n d a n d th e Czech Repu blic. In deed, it is
a r gu a ble th a t ou tdoor a ir pollu tion a m on g
n a tion s w ith com m on bou n da r ies is so w idespr ea d a s to ju stify its con sider a tion a s a n
a r ea of globa l con cer n . Th er e a r e m a n y for m s
of ou tdoor a ir pollu tion a n d th is pa per w ill
focu s on ju st a few exa m ples. On e com m on
type of ou tdoor a ir pollu ta n t is r efer r ed to a s
su spen ded pa r ticu la te m a tter (SP M). SP M
r efer s to th e w ide r a n ge of fi n ely divided
solids or liqu ids disper sed in to th e a tm osph er e fr om n a tu r a l sou r ces, in du str ia l a ctivities a n d com bu stion pr ocesses. Th e com position of SP Ms va r ies bu t typica lly in clu des
ca r bon , h igh er h ydr oca r bon s for m ed by
in com plete com bu stion of h ydr oca r bon fu els,
a n d su lph u r, th e la tter of wh ich m ay a ccou n t
for u p to a ppr oxim a tely 20 per cen t of th e tota l
SP Ms (E lsom , 1992, p. 21). Th u s, th e effects of
SP Ms on th e en vir on m en t a r e h igh ly in fl u en ced by su lph u r -ba sed em ission s. Th e
h ea lth im pa ct of su ch levels of em ission s is
tr em en dou s a n d exposu r e to SP Ms h a s been
lin k ed w ith h igh er in ciden ce of a sth m a , br on ch itis a n d pu lm on a r y em ph ysem a (E lsom ,
1992, p. 27).
An oth er com m on type of a ir pollu ta n t is
su lph u r dioxide. Th is is a colou r less ga s em itted fr om sou r ces sim ila r to SP Ms. Its em ission is h igh est fr om th e com bu stion of coa l
a n d oil. Su lph u r dioxide r ea cts ca ta lytica lly
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or ph otoch em ica lly w ith oth er pollu ta n ts to
for m su lph u r tr ioxide, su lph u r ic a cid a n d
su lph a tes (E lsom , 1992, p. 22). Su lph u r is h istor ica lly r e ga r ded a s on e of th e tr a dition a l
sou r ces of pollu tion . At its zen ith , su lph u r
pollu tion h a s m a n ifested itself in th e fa m ou s
su lph u r ou s sm ogs th a t a fflicted m ost in du str ia l cities. Sm ogs a r e gen er a lly for m ed wh en
m eteor ologica l con dition s fa il to disper se
la r ge qu a n tities of pollu ta n ts em itted fr om
in du str y, veh icles a n d dom estic sou r ces. Su lph u r -r ela ted pr odu cts ca n h ave a fa ta l im pa ct
on h u m a n h ea lth a s eviden ced by th e in fa m ou s su lph u r ou s sm og th a t str u ck Lon don in
Decem ber 1952. Th e dea th of n ea r ly 4, 000
people w a s th e r esu lt w ith th e la r gest con tr ibu tor bein g br on ch itis, followed by oth er disea ses ch a r a cter ized by im pa ir m en t of r espir a tor y fu n ction s (E lsom , 1992, pp. 22-5). On a
less fa ta l ba sis, su lph u r dioxide pr odu ces a
str on g ir r ita tion on th e eyes a n d th e n a sa l
pa ssa gew ay. Mor eover, su lph u r dioxide em ission s h ave been lin k ed w ith h igh er
in ciden ces of a sth m a , br on ch itis, pu lm on a r y
em ph ysem a a n d a gen er a l r edu ction of lu n g
fu n ction s especia lly in ch ildr en (Wellbu r n ,
1988, pp. 53-6). An oth er pa r ticu la r va r ia tion of
su lph u r em ission s is h ydr ogen su lph ide. It is
sligh tly ph ototoxic a n d a t h igh levels it ca n
ir r ita te th e lu n g pa ssa ge a n d eyes of h u m a n s
possibly r esu ltin g in pn eu m on ia a n d con ju n ctivitis (Wellbu r n , 1988, pp. 182-6).
Oxides of n itr ogen a r e a lso da n ger ou s
sou r ces of a ir pollu tion . Th e pr in cipa l a n th r opogen ic em ission s of oxides of n itr ogen a r e
fr om th e com bu stion of fossil fu els in fixed
sou r ces lik e power pla n ts a n d h ea tin g, a n d in
m otor ca r s fr om th e in ter n a l com bu stion
en gin e. In developed cou n tr ies, th e oper a tion
of power pla n ts con tr ibu tes a ppr oxim a tely 45
per cen t of th e em ission of oxides of n itr ogen ,
r oa d tr a n spor t a bou t 30 per cen t, w ith th e
ba la n ce fr om dom estic a n d gen er a l in du str ia l
sou r ces (Wellbu r n , 1988, p. 68). Th e h ea lth
im plica tion s of em ission of oxides of n itr ogen
m ay n ot be a s power fu l a s oth er a ir pollu ta n ts
bu t ou gh t n ot to be u n der estim a ted. N itr ogen
dioxide is k n ow n for its stin gin g, su ffoca tin g
odou r. F u r th er, eviden ce poin ts to in cr ea sed
a ir w ay r esista n ce a n d sen sitivity to br on ch ocon str ictor s in cer ta in in dividu a ls
(E lsom , 1992, p. 49). At h igh levels of exposu r e,
n itr ou s fu m es m ay ca u se cou gh in g,
h ea da ch es a n d ch est tigh tn ess. Th is m ay lea d
to su dden cir cu la tor y colla pse a n d w a ter
a ccu m u la tion in th e lu n gs. E xcess blood
n itr a te m ay r edu ce blood pr essu r e wh ich in
tu r n cou ld ca u se destr u ction of blood cells,
liver a n d k idn ey defects (Wellbu r n , 1988,
p. 91).
P h otoch em ica l oxida n ts a lso con tr ibu te to
th e da n ger ou s cock ta il of a ir pollu ta n ts th a t
a r e pr esen t today. E va por a tion of solven ts a n d
fu els togeth er w ith th e in com plete com bu stion of fossil fu els ca u ses va r iou s h ydr oca r bon s to be r elea sed in to th e a tm osph er e (Wellbu r n , 1988, p. 135). P h otoch em ica l oxida n ts
a r e secon da r y pollu ta n ts for m ed by th e
a ction of su n ligh t on a n a tm osph er e con ta in in g r ea ctive h ydr oca r bon s a n d oxides of
n itr ogen . Th ese r ea ction s pr odu ce m a n y
oxida n ts w ith per oxya cetyl n itr a te a n d ozon e
bein g th e m ost sign ifica n t. Th e k ey to th e
for m a tion of ozon e is th e ph otolysis of th e
n itr ogen dioxide m olecu le by u ltr aviolet
r a dia tion du r in g dayligh t h ou r s. P h otoch em ica l oxida n ts in th eir sm oglik e for m a r e ca pa ble of ca u sin g eye a n d n ose ir r ita tion . Du r in g
episodes in Los An geles in Septem ber 1979, 55
per cen t of th e people su r veyed com pla in ed of
bu r n in g or ir r ita tion of th e eyes, 25 per cen t
r epor ted h ea da ch es, br ea th in g ir r ita tion ,
sor e th r oa ts or stu ffy n oses, wh ile h ospita ls
r ecor ded a lm ost a 50 per cen t a dm itta n ce r a te
in
Rajendra Ramlogan
Unive rsity o f Cambridge , UK
Focuses on the direct and
indirect impact of environmental abuse on human
wellbeing. In some instances,
the impact of environmental
abuse on human health is not
still unknown, merely being
subject to scientifi c suspicion. This would suggest
caution and the need for
preventive measures to be
applied. The threat to human
health from environmental
factors is not an isolated
problem that exists on a
national level. There are
environmental factors that
affect human health on a
global level or are so widespread as to be considered
global problems. Other environmental problems cross
national boundaries and
achieve regional importance.
Enviro nme ntal Manage me nt
and He alth
8 / 2 [ 1997] 5 1 –6 6
© MCB Unive rsity Pre ss
[ ISSN 0956-6163]
Introduction
Th e wor ld th a t we in h a bit h a s been sh a ped
la r gely by a cts of n a tu r e a n d of m a n . Th e
su bject of th e sh a pin g of th e en vir on m en t by
n a tu r a l for ces a n d its effect on m a n does n ot
for m pa r t of th is r eview. In stea d th is pa per is
dedica ted solely to a n a n a lysis of th e r ole of
m a n in th e a bu se of th e en vir on m en t a n d th e
exten t to wh ich th is a ffects h u m a n h ea lth a n d
wellbein g. Th er e is a lon g lita n y of m a n ’s
m isu se of h is en vir on m en t, a n d eviden ce
sh ow s th a t th e situ a tion h a s wor sen ed dr a m a tica lly over th e la st 300 yea r s. Th e con fl ict
a ppea r s to h ave in ten sified, cr ea tin g con cer n
th a t we m ay be pu sh in g ou r selves to th e
br in k of a globa l disa ster. F a ctor s su ch a s th e
In du str ia l Revolu tion of th e m id-eigh teen th
cen tu r y, wh ich sta r ted in Br ita in a n d m a de
its w ay to E u r ope a n d N or th Am er ica , a n d
th e in sa tia ble a ppetite for fu el, a n d th e gr ea t
tech n ologica l str ides th a t a ccom pa n ied th e
In du str ia l Revolu tion , u r ba n iza tion , th e com m er cia liza tion of a gr icu ltu r e, th e r ise in
con su m er ism , a n d popu la tion gr ow th , h ave
often been h er a lded a s th e tu r n in g poin t for
th e m oder n cr isis th a t h a s a r isen between
m a n a n d th e en vir on m en t. Yet despite th e
ea r ly sta r t to en vir on m en ta l pr oblem s, it is
per h a ps tr u e th a t a s th e twen tieth cen tu r y
pr epa r es to give w ay to th e twen ty-fir st, th e
fu ll sca le of th e h ea lth im plica tion s of en vir on m en ta l de gr a da tion h a s sta r ted to be
r evea led.
Good h ea lth h a s been on e of th e m a jor goa ls
of h u m a n k in d th r ou gh ou t th e m a r ch of h istor y. Th e Wor ld Hea lth Or ga n iza tion (WHO)
defin es h ea lth a s th e sta te of com plete ph ysica l, m en ta l a n d socia l wellbein g of m a n ; n ot
m er ely fr eedom fr om disea se or in fi r m ity
(Weisn er, 1992, p. 1). It h a s been a r gu ed th a t
th e ba sic r equ ir em en ts for a n a ccepta ble level
of h ea lth a r e a su ita ble diet, decen t sh elter,
com pa n ion sh ip, a n a dequ a te in com e a n d a
h ea lth y en vir on m en t. Im por ta n tly, good
h ea lth r equ ir es a con str u ctive ba la n ce
between in dividu a ls or gr ou ps a n d th e en vir on m en t (Weisn er, 1992, pp. 2-4). It is bein g
r ecogn ized th a t th e ph ysica l en vir on m en t is
th e m ost im por ta n t deter m in a n t of good
h ea lth a n d, con sequ en tly, pr otection of th e
en vir on m en t a n d pr eser va tion of ecosystem s
a r e fu n da m en ta l in th e str u ggle a ga in st
h u m a n illn esses (Cor tese, 1993, pp. 1-3). E xistin g eviden ce su ggests th a t th e m ost ser iou s
poten tia l con sequ en ce of globa l en vir on m en ta l ch a n ge is th e decim a tion of th e E a r th ’s
life-su ppor t system s (McMich a el, 1993, p.
xiii). Cor tese h a s a sser ted th a t r a pid in du str ia l gr ow th , th e popu la tion explosion ,
r esou r ce depletion , a lter a tion of th e ch em ica l
com position of th e a tm osph er e a n d th e
cyclin g of ca r bon , n itr ogen a n d ph osph or ou s
a r e fa ctor s la r gely r espon sible for a lter in g
th e ba sic ph ysiology of th e E a r th (Cor tese,
1993, p. 2; Godlee a n d Wa lk er, 1992, pp. 1-8). In
th e wor ds of McMich a el (1993), it wou ld
a ppea r “th a t th is fa br ic of life-su ppor tin g
m ech a n ism s is n ow sta r tin g to u n r avel, in a
br ief geologica l m om en t, a s th e cu m u la tive
globa l im pa ct of h u m a n a ctivity esca la tes”
(p. 5)”.
On e of th e in cr ea sin gly a ppa r en t fea tu r es of
life in th e la tter h a lf of th e twen tieth cen tu r y
is th e gr ow in g in ter depen den cy of th e globa l
villa ge. Th is tr en d tow a r ds a sm a ller, m or e
a ccessible a n d in ter r ela ted wor ld h a s ju stifi a bly led to m a n y differ en t a r ea s of con cer n ,
on e of wh ich per ta in s to th e en vir on m en t.
Developin g a u n ifor m defin ition of wh a t is
m ea n t by th e ter m “en vir on m en t” h a s pr oved
elu sive. For pu r poses of th is pa per, a wor k in g
defin ition of th e en vir on m en t sh a ll r efer to:
• th e ph ysica l elem en ts of th e E a r th , n a m ely
th e a ir, w a ter, la n d su r fa ce, su b-su r fa ce
str a ta (togeth er w ith a ll livin g r esou r ces
th er ein );
• ou ter spa ce;
• a m bien t ba ck gr ou n d a n d h u m a n h a bita tion s;
• th e wor k pla ce;
• in digen ou s peoples; a n d
• th e n a tu r a l, cu ltu r a l a n d com m on h er ita ge
of th e wor ld.
Wh ile th er e m ay be m a n y con sequ en ces of
en vir on m en ta l de gr a da tion in th e globa l
com m u n ity, on e of th e em er gin g pr in cipa l
con cer n s lies in th e a r ea of h u m a n h ea lth .
Th is pa per is dedica ted to th e r eview of existin g scien tific in vestiga tion s so a s to develop a
gr ea ter u n der sta n din g of h ow en vir on m en ta l
fa ctor s ca n im pa ct n ot on ly on n a tion a l a n d
r e gion a l com m u n ities, bu t a lso on th e in ter n a tion a l com m u n ity a n d a dver sely a ffect th e
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a spir a tion s of h u m a n society for a better
fu tu r e. Th u s, a s th e con flict between m a n a n d
th e en vir on m en t in ten sifi es, it wou ld be w ise
to bea r in m in d th a t th e h u m a n body m ay pay
th e u ltim a te pr ice for th e in discr etion s of th e
h u m a n r a ce.
Environmental degradation and
human health: the global village
Global warming
Clim a te ch a n ge is destin ed to a ffect th e en tir e
globa l villa ge a s it is a pla n eta r y occu r r en ce.
A w a r m er wor ld is for eca st a s a r esu lt of th e
effects of gr een h ou se em ission s. It is n ow
th ou gh t th a t h u m a n h ea lth m ay be a ffected
by globa l w a r m in g. Un der w a r m er con dition s, h ea t str ess r ela ted con dition s m ay
becom e m or e com m on , lea din g to in cr ea ses
in m or bidity a n d m or ta lity (Lon gstr eth , 1990,
p. 525; Sch n eider, 1989, p. 182). Wa r m er su m m er s m ay pr odu ce h igh er in fa n t a n d foeta l
m or ta lity du e to su m m er tim e in cr ea ses in
in fection s (Lon gstr eth , 1990, p. 525). Moister
a n d w a r m er con dition s wou ld fa cilita te th e
n or th w a r d spr ea d of in sect-bor n e disea ses,
for exa m ple, fr om m osqu itoes a n d tick s
(Sch n eider, 1989, p. 182). On e possible disea se
th a t m ay flou r ish u n der con dition s of globa l
w a r m in g is m a la r ia . Addition a lly, w a r m er
a n d m oister con dition s m ay lea d to h igh er
r a tes of sk in in fection s (Lon gstr eth , 1990, p.
525).
Depletion of the stratospheric ozone layer
An oth er en vir on m en ta l pr oblem w ith globa l
con sequ en ces is th e depletion of th e str a tosph er ic ozon e layer, a n d h er e h u m a n h ea lth
m ay ver y well pr ove to be th e m ost dir ect
ca su a lty. E xposu r e to u ltr aviolet-B r a dia tion
ca n ca u se a su ppr ession in im m u n e system s
lea din g to a n in cr ea se in in fection s (Mor ison ,
1992, p. 49). Addition a lly, th er e m ay even be a
possible decr ea se in th e effectiven ess of va ccin es (UN E P, 1990, p. 116). Sk in pigm en ta tion
wou ld n ot pr otect a ga in st deficien cies in th e
im m u n e system , so r en der in g per son s in th e
tr opics equ a lly a t r isk (Ilya s, 1989; J eeva n a n d
Kr ipk e, 1993, p. 1160).
E n h a n ced levels of u ltr aviolet-B r a dia tion
ca n lea d to in cr ea sed da m a ge to th e eyes,
lea din g to a h igh er in ciden ce of ca ta r a cts.
Ca ta r a cts ca n im pa ir vision a n d even ca u se
blin dn ess. It h a s been estim a ted th a t th e
in ciden ce of ca ta r a cts wou ld in cr ea se by 0.6
per cen t per 1 per cen t ozon e depletion . Th is
m ay r esu lt in a n a ddition a l 100,000 ca ses of
blin dn ess wor ldw ide (UN E P, 1990, p. 116).
With r espect to oth er ocu la r a ilm en ts, it is
a n ticipa ted th a t th er e wou ld be a r ise in ca ses
of k er a to-con ju n ctivitis or sn ow blin dn ess.
[ 52 ]
F in a lly, lon g-ter m in cr ea ses in u ltr aviolet-B
ir r a dia n ce w ill en h a n ce th e r isk of n on m ela n om a sk in ca n cer (Ma dr on ich a n d De
Gr u jl, 1994, pp. 541-6). It is pr ojected th a t
ever y 1 per cen t decr ea se in th e tota l ozon e
colu m n w ill r esu lt in a 3 per cen t r ise in th e
in ciden ce of n on -m ela n om a ca n cer (Diffey,
1992, pp. 2267-79; UN E P, 1990, p. 116). Ca ses of
th e m or e da n ger ou s m a lign a n t m ela n om a a r e
a lso a n ticipa ted (Hen r ik sen et a l., 1990, pp.
579-82; J on es, 1989, p. 213). Ultr aviolet-B r a dia tion ca n in cr ea se m or ta lity a n d m or bidity
sign ifica n tly th r ou gh m ela n om a a n d n on m ela n om a sk in ca n cer s. On a less ser iou s
level to sk in ca n cer, u ltr aviolet-B r a dia tion
ca n a lso r esu lt in a cu te er yth em a or su n bu r n ,
a con dition th a t w ill especia lly a fflict ligh t
sk in n ed people (J on es, 1989, p. 208). Th e effect
of ozon e depletion wou ld be to sh ift popu la tion s closer to equ a tor ia l con dition s of u ltr a violet exposu r e th a n gen etica lly per m issible
(J on es, 1989, p. 215). Developin g cou n tr ies
w ith a lr ea dy u n der developed h ea lth -ca r e
system s wou ld su ffer tr em en dou sly if th er e is
a n u psu r ge in in fection r a tes or ca ta r a ct
for m a tion (Tolba a n d E l-Kh oly, 1993, p. 34).
M arine resource
Th e th r ea t to th e ocea n s by pollu tion is ca pa ble of cr ea tin g h avoc th r ou gh ou t th e wor ld.
Pollu tion of ocea n s or igin a tes fr om m a n y
sou r ces. Today over 60 per cen t of th e wor ld’s
popu la tion live w ith in th e vicin ity of a coa stlin e, w ith two-th ir ds of th e wor ld’s cities w ith
popu la tion s of m or e th a n 2.5 m illion situ a ted
n ea r estu a r ies (Tolba a n d E l-Kh oly, 1993,
p. 107). Th is h igh level of popu la tion in th e
vicin ity of ocea n s h a s led to th e dir ect du m pin g of m u n icipa l w a stes a t sea , wh er e ver y
often liqu id a n d sem i-solid w a stes a r e sim ply
pu m ped th r ou gh sh or t pipes (Wh ite, 1993,
p. 87). Addition a lly, m a n ’s u se of th e ocea n s
h a s led to pollu tion fr om w ith in th e ocea n . It
is estim a ted th a t a ppr oxim a tely 6.4 m illion
ton s of gen er a l sh ipboa r d litter a r e du m ped
a n n u a lly by sh ips a t sea (Tolba a n d E l-Kh oly,
1993, p. 120). F u r th er, ocea n u ser s m a in ly
involved in th e fish in g in du str y gen er a te
136,000 ton s of pla stic, n ets, lin es a n d bu oys
a n d 22,000 ton s of pla stic con ta in er s, a ll of
wh ich con tr ibu te to litter in g of th e ocea n
(Wh ite, 1993, p. 85).
Hydr oca r bon pollu tion is on e of th e best
k n ow n sou r ces of ocea n con ta m in a tion . Yet
su r pr isin gly, specta cu la r oil ta n k er spilla ges
con tr ibu te a m er e 22 per cen t to th e h ydr oca r bon pollu tion of ocea n s. An over wh elm in g 59
per cen t com es fr om th e r ou tin e flu sh in g of
oil ta n k er h olds. Ra dioa ctive w a ste is a lso a
con tr ibu tor to pollu tion of ocea n s a s th ese
ecosystem s wer e con sider ed du m ps of la st
r esor t. In som e in sta n ces solid m u n icipa l
w a ste a n d even h a za r dou s w a ste a r e sim ply
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tr a n spor ted ou t in to th e sea a n d du m ped.
In r ecen t tim es, h a za r dou s w a ste w a s tr a n spor ted to sea a n d in cin er a ted. Ash es a n d
oth er con ta m in a n ts th a t a r e n ot effectively
n eu tr a lized by in cin er a tion a r e du m ped a t
sea (Wh ite, 1993, pp. 86-7). F in a lly, offsh or e
m in in g a ctivities h ave con tr ibu ted to th e
pollu tion of th e ocea n s. In Th a ila n d it h a s
been discover ed th a t offsh or e tin m in in g h a s
de gr a ded sea w a ter qu a lity a n d da m a ged r eef
ecosystem s (Ru ya bh or n a n d P h a n tu m va n it,
1988, p. 229).
By fa r th e gr ea test h ea lth th r ea t fr om pollu tion of th e wor ld’s ocea n s com es fr om fi sh
con ta m in a tion . Th e Un ited N a tion s E n vir on m en ta l P r ogr a m m e (UN E P ) h a s estim a ted
th a t over 20 billion ton s of w a ste in clu din g
sew a ge, a gr icu ltu r a l r u n -off a n d in du str ia l
w a ste a r e du m ped in to th e ocea n a n n u a lly.
Appr oxim a tely 90 per cen t r em a in n ea r coa stlin es wh ich , togeth er w ith r eefs pr ovide
a r ou n d 95 per cen t of th e wor ld’s fi sh ca tch
(Tolba a n d E l-Kh oly, 1993, p. 117; Wh ite, 1993,
p. 87). F ish con ta m in a tion ca n h ave ser iou s
h ea lth im plica tion s. Th e con su m ption of
con ta m in a ted sea food ca n lea d to ser iou s
h ea lth pr oblem s, pa r ticu la r ly in developin g
cou n tr ies wh er e, a s n oted befor e, th e ocea n s
pr ovide th e m a jor sou r ce of pr otein . Th e
Min im a ta m er cu r y poison in g in ciden t in
J a pa n is a n exa m ple of th e a dver se con sequ en ces of con su m in g con ta m in a ted sea food
(Wh ite, 1993, pp. 85-6). In Min im a ta m er cu r y
w a ste pr odu ced by a loca l in du str y w a s
pou r ed in to th e sea to en ter th e h u m a n food
ch a in th r ou gh con ta m in a ted sea food. Th e
r esu lt w a s th e on set of debilita tin g h u m a n
illn esses a ssocia ted w ith m er cu r y poison in g.
Chemicals
Th er e a r e cer ta in a r ea s of envir on m en ta l
de gr a da tion th a t a lth ou gh ta k in g pla ce
w ith in n a tion a l bou n da r ies a r e so
w idespr ea d a s to ju stify globa l con cer n . On e
su ch a r ea is ch em ica l pollu tion . F r om tim e
im m em or ia l, m a n h a s en ga ged in th e m a n u fa ctu r e of ch em ica ls. Th ese pr odu cts a r e u sed
on ou r bodies, in ou r h om es, fi elds, food,
tr a n spor t a n d in deed in a lm ost ever y a spect
of ou r life. It h a s been ca lcu la ted th a t between
1956 a n d 1982, over 4 m illion distin ct ch em ica l
com pou n ds wer e for m u la ted w ith a s m a n y a s
6,000 n ew for m u la tion s bein g cr ea ted week ly
sin ce. Wilson (1993) sta tes th a t a ppr oxim a tely
3,000 ch em ica ls a r e deliber a tely a dded to
food, 700 h ave been fou n d in dr in k in g w a ter,
a bou t 400 h ave been iden tified in h u m a n tissu es a n d over 500 cou ld be fou n d u n der th e
k itch en sin k or in th e la u n dr y r oom of th e
aver a ge h ou se. Th e fa ct th a t over 70,000 ch em ica ls a r e in da ily u se cr ea tes a ca u se for con cer n especia lly w ith r e ga r d to issu es of h ea lth
a n d sa fety (p. 1).
Pesticides a r e pr oba bly th e m ost
w idespr ea d a n d in fa m ou s sou r ce of ch em ica l
con ta m in a tion wh ich exists in th e a tm osph er e, w a ter, soil a n d food. Th e wor ld wok e
u p to th e h or r or s of th e in discr im in a te u se of
pesticides w ith th e pu blica tion of th e fa m ou s
S ilen t S pr in g by Ra ch el Ca r son (1991). Th e
w idespr ea d u se of pesticides is a fea tu r e of
th e twen tieth cen tu r y, th e m a n ifesta tion of
a n oth er tool to a sser t con tr ol over n a tu r e.
Th e r ise of pesticides is in tim a tely lin k ed
w ith th e discover y in 1939 of th e in secticida l
ca pa bilities of dich lor o-diph en yl-tr ich lor oeth a n e (DDT) (McE wen a n d Steph en son , 1979
pp. 2-4). F r om th a t poin t on w a r ds pesticides
h ave played a n im por ta n t r ole in h u m a n
society. Th ey h ave been u sed for a m yr ia d
ca u ses, su ch a s th e con tr ollin g of pests,
en h a n cem en t of cr ops, destr u ction of disea seca u sin g in sects a n d im pr ovem en t of h ou seh old con dition s by er a dica tin g th ose livin g
or ga n ism s th a t h ave led to discom for t in
dwellin g pla ces (McE wen a n d Steph en son ,
1979, pp. 8-19).
T h e a dver se effect s of ch em ica ls on h u m a n
h ea lt h is by fa r t h e m ost im por t a n t a r ea of
con cer n . Ch em ica l con t a m in a t ion ca n en t er
t h e or ga n s of livin g t h in gs t h r ou gh a ir, w a t er
a n d food. Sim ple in h a la t ion of con t a m in a t ed
a ir ca n in du ce a dver se r ea ct ion s in t h e
h u m a n body. Food is a n im por t a n t sou r ce of
ch em ica l con t a m in a t ion t h a t fa cilit a t es t h e
in gr ess of h a r m fu l ch em ica ls in t o livin g
t h in gs. Con t a m in a n t s ca n be a cqu ir ed a t t h e
pr odu ct ion , h a r vest in g, pr ocessin g, pa ck a gin g, t r a n spor t , st or a ge, cook in g a n d ser vin g
st a ges. T h e a pplica t ion of pest icides a n d
pr eser va t ives con t a m in a t es food beca u se of
t h e per sist en ce of ch em ica l r esidu es. N or m a l
levels of a ir bor n e ch em ica l con t a m in a n t s
ca n con t r ibu t e t o con t a m in a t ion of food bu t
t h e r esu lt m ay n ot n ecessa r ily be a cu t e t oxicit y. Wa t er ca n con t a m in a t e food in sever a l
w ays. Con su m pt ion of fi sh a n d sh ellfi sh con t a in in g ch em ica l con t a m in a n t s pr ovides a
pa t h w ay for ch em ica ls t o en t er in t o t h e
h u m a n body. Con su m pt ion of ve get a ble pr odu ct s t h a t m ay h ave been cu lt iva t ed w it h con t a m in a t ed ir r iga t ed w a t er is a n ot h er sign ifi ca n t pa t h w ay. E ven t h e con su m pt ion of livest ock wh ich m ay h ave dr u n k con t a m in a t ed
w a t er is a possible con du it for t h e t r a n sfer of
ch em ica l con t a m in a t ion (Lippm a n n a n d
Sch lesin ger, 1979, pp. 24-7). Addit ion a lly, t h e
dr in k in g of ch em ica lly t a in t ed w a t er is a lso a
pr edict a ble w ay of becom in g exposed t o t h e
h a r m fu l effect s of ch em ica ls (McE w en a n d
St e ph en son , 1979, pp. 280-1). F in a lly,
con su m pt ion of cr ops gr ow n on ch em ica lly
t a in t ed soils r e pr esen t s a n ot h er possible
en t r y poin t for ch em ica l con t a m in a n t s in t o
t h e h u m a n body.
[ 53 ]
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[ 54 ]
In th e m a jor ity of ca ses exposu r e is via
in h a la tion bu t it ca n a lso r esu lt fr om exposu r e of th e sk in (Lippm a n n a n d Sch lesin ger,
1979, p. 51). Th e r espir a tor y tr a ct is th e m a in
poin t of en tr y in to h u m a n s for a ir bor n e
ch em ica ls. Ch em ica ls wh ich a r e w a ter bor n e
or tr a n spor ted in food r ea ch m a n th r ou gh th e
ga str oin testin a l tr a ct. Th ese ca n a lso be
a bsor bed in to th e h u m a n body th r ou gh th e
sk in . Th e r a n ge of biologica l r espon ses to
ch em ica l con ta m in a n ts in th e body is qu ite
diver se a n d m ay r a n ge fr om ir r ita n t, fibr otic,
a sph yxia n t, a ller gic to ca r cin ogen ic (Lippm a n n a n d Sch lesin ger, 1979, pp. 194-214). It
h a s been estim a ted th a t th r ee ou t of ever y ten
people in th e USA ca n expect to con tr a ct
som e for m of ca n cer, a n d in a ppr oxim a tely 98
per cen t of th e ca ses th ese m ay be lin k ed to
ch em ica l exposu r e. In a ddition to ca n cer,
ch em ica l exposu r e is r espon sible for a m yr ia d oth er h ea lth pr oblem s r a n gin g fr om n eu r ologica l, im m u n ologica l a n d developm en ta l
to r epr odu ction (Wilson , 1993, pp. 2-4). Wilson
pr ovides on e of th e m ost com pr eh en sive tr ea tises on th e h ea lth im plica tion s of va r iou s
ch em ica ls. Th e list of h u n dr eds of lik ely a ilm en ts fr om ch em ica l exposu r e is a ch illin g
r em in der of h u m a n vu ln er a bility (Wilson ,
1993, pp. 11-72). With ou t dou bt, exposu r e to
h a r m fu l ch em ica ls ca n in cr ea se m or ta lity
a n d m or bidity (Bla in , 1990). Most ca ses of
w idespr ea d m or ta lity a r e th e r esu lt of in du str ia l a cciden ts a n d spilla ge of ch em ica ls a s
occu r r ed in Bh opa l, in In dia . However,
a lth ou gh dea th s h ave occu r r ed th r ou gh less
specta cu la r m edia , th er e a r e m u ch fewer da ta
ava ila ble in ca ses wh er e th e exposu r e m ay
h ave been a lon g-ter m pr oblem (Lippm a n n
a n d Sch lesin ger, 1979, pp. 53-4).
Th e occu pa tion a l en vir on m en t is a n oth er
m a jor sou r ce of exposu r e to h a r m fu l ch em ica ls a m on g h u m a n s a n d m er its specia l m en tion . It h a s been a sser ted th a t m ost ca ses of
ch em ica l poison in g h ave a r isen fr om occu pa tion a l exposu r e. Mor e th a n ever, ch em ica l
pr odu ction is sh iftin g to developin g cou n tr ies
wh er e th e r e gu la tor y fr a m ewor k is less
sever e th a n in developed cou n tr ies. Th e
r esu lt h a s been a r ise in ca ses of ch em ica l
poison in g a lth ou gh th er e is sign ifi ca n t u n der r epor tin g a n d la ck of r esea r ch in th is a r ea .
Va r iou s stu dies, h owever, h ave led to r ea son a ble estim a tes of th e m a gn itu de of th e pr oblem . In Ta iw a n it w a s discover ed th a t em ployees in a pla n t en ga ged in th e m a n u fa ctu r e of
pesticides h a d su bsta n tia lly decr ea sed
pla sm a ch olin ester a se (Wu , 1989, pp. 661-3).
N ot on ly th ose wh o m a n u fa ctu r e th e pesticides a r e a ffected bu t wor k er s wh o a r e
en ga ged in a dm in ister in g th e ch em ica ls a r e
equ a lly, if n ot m or e, a t r isk . A stu dy in In dia
r evea led a pr eva len ce of r espir a tor y a ilm en ts
a m on g spr ayer s in m a n go pla n ta tion s. Th e
spr ayer s, beca u se of a n a bsen ce of pr oper
sa fety equ ipm en t, wer e dir ectly exposed to
th e pesticides th r ou gh sk in con ta ct a n d r espir a tion a n d in dir ectly th r ou gh food con su m ption (Ra stogi, 1989). Th e pr oblem of im pr oper
pr otection of wor k er s u sin g pesticides h a s
given r ise to wh a t h a s been descr ibed a s a n
epidem ic of pesticide poison in g in N ica r a gu a
(McCon n ell a n d Hr u sk a , 1993).
Th e exa m ples n oted a bove in th e ca se of
wor k er s dea lin g w ith h a r m fu l ch em ica ls a r e
n ot isola ted bu t in dica tive of a m u ch br oa der
pr oblem a n d pesticide poison in g h a s em er ged
a s a m a jor con cer n . WHO a n d UN E P h ave
estim a ted th a t over on e m illion ca ses of pesticide poison in g occu r yea r ly, w ith a r ou n d
20,000 fa ta lities (P im en tel et a l., 1992, p. 750).
A m or e r ecen t stu dy h a s su ggested th a t th e
in ciden ts of pesticide poison in g m ay be a s
h igh a s th r ee m illion a n n u a lly (McCon n ell
a n d Hr u sk a , 1993, p. 1559). In spite of th e
developed cou n tr ies u sin g a r ou n d 80 per cen t
of th e pesticides pr odu ced in th e wor ld, it h a s
been estim a ted th a t 99 per cen t of pesticide
fa ta lities occu r in th e developin g wor ld, w ith
ju st a s sign ifica n t a per cen ta ge in th e a r ea of
n on -fa ta l poison in gs. An oth er a r ea of con cer n in th e developin g wor ld is th e h igh level
of per in a ta l m or ta lity. It h a s been estim a ted
th a t th er e a r e a bou t seven m illion per in a ta l
dea th s per a n n u m in developin g cou n tr ies. A
stu dy in Su da n h a s in dica ted a con sisten t a n d
sta tistica lly sign ifica n t r ela tion sh ip between
exposu r e to pesticides a n d th e in cr ea sed r isk
of still bir th or per in a ta l dea th (Ta h a a n d
Gr ay, 1993, pp. 319-20).
Nuclear operations
N u clea r oper a tion s a r e n a tion a l a ctivities
w ith globa l im plica tion s. Th e biggest fea r
per ta in in g to n u clea r a ctivities a r ises fr om
th e possibility of th e u se of n u clea r tech n ology a s a wea pon a n d n u clea r a cciden ts. Th e
ter r estr ia l en vir on m en t ca n becom e a ffected
by r a dion u clides em itted or disch a r ged eith er
a cciden ta lly or deliber a tely fr om a ser ies of
pa th w ays. Th er e ca n be dir ect deposition of
con ta m in a ted soils by fl oodin g or ir r iga tion
w ith con ta m in a ted w a ter, or a er ia l wet or dr y
deposition . Accor din gly, ter r estr ia l ve geta tion m ay becom e con ta m in a ted a s a r esu lt of
dir ect deposition or r a dion u clides en ter in g
fr om th e soil (Pen tr ea th , 1980, p. 173). Som e
em ission s lik e iodin e-131 a fter deposition on
folia ge ca n be dir ectly in gested fr om a ffected
fr u its a n d ve geta tion or th r ou gh th e cow m ilk -m a n pa th w ay (Pen tr ea th , 1980, pp. 146-7).
Th u s, m a n m ay be a ffected by r a dioa ctive
em ission s th r ou gh con su m ption of fr u its a n d
ve geta tion , cow ’s m ilk or m ea t fr om a n im a ls
th a t m ay h ave con su m ed con ta m in a ted
ve geta tion (Pen tr ea th , 1980, pp. 180-1). Th e
disch a r ge of liqu id efflu en ts in th e a qu a tic
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envir on m en t ca n a lso fin d its w ay in to th e
h u m a n body eith er by dr in k in g a ffected w ater
or con su m ption of fish a n d oth er a qu a tic
sou r ces of h u m a n food th a t m ay h ave been
con ta m in a ted (Pen tr ea th , 1980, pp. 158-65).
A da n ger ou s th r ea t to h u m a n h ea lth a r isin g fr om th e u se of n u clea r tech n ology is th e
possibility of exposu r e to r a dia tion . In ju r y to
livin g or ga n ism s a r ises fr om da m a ge to cells
in th e body. High levels of r a dia tion lea d to
both som a tic a n d gen etic ch a n ges in livin g
or ga n ism s. Som a tic effects a r e th ose r esu ltin g dir ectly fr om th e r a dia tion dose r eceived
by th e a ffected cells a n d m a n ifest th em selves
in som e for m of r a dia tion -in du ced m a lign a n cy (E ich h olz, 1977, p. 121). Th e effects
in clu de in cr ea sed in ciden ce of leu k a em ia a n d
oth er types of ca n cer, in clu din g tu m ou r s of
th e th yr oid gla n d, lu n g, a n d th e br ea st in
wom en . High er in ciden ce of bon e ca n cer h a s
a lso been obser ved in som e in sta n ces (Gla sston e a n d J or da n , 1980, pp. 184-91). Gen etic
effects a r ise wh en th e r epr odu ctive cells a r e
ir r a dia ted, r esu ltin g in ch a n ges in th e gen es
or ch r om osom es of th ese cells, a n d th e su bsequ en t h a n din g dow n of th ese ch a n ges to
descen da n ts of th e a ffected in dividu a l. Th er e
a r e differ en t types of gen etic ch a n ges,
n a m ely, gen e m u ta tion s, ch r om osom e a ber r a tion s, a n d ch a n ges in th e n u m ber of ch r om osom es. Th ese ch a n ges ca n r esu lt in th e pr esen ce of a bn or m a lities in offspr in g r a n gin g
fr om leth a l to m ildly detr im en ta l (E ich h olz,
1977, p. 123).
Environmental degradation and
human health: the regional
connection
Freshwater
Wa ter is th e essen ce of life, w ith ou t wh ich
m a n ’s existen ce ca n be tr a n sfor m ed in to on e
con tin u ou s litu r gy of su ffer in g. Th is is cu r r en tly eviden t in pla ces lik e th e Sa h el r e gion .
However, in a ddition to w a ter ava ila bility,
w a ter qu a lity a lso poses a pr oblem , pa r ticu la r ly in developin g cou n tr ies. It m ay be a ccu r a te to sta te th a t th e n eed for a sa fe dom estic
w a ter su pply is per h a ps th e gr ea test th r ea t to
th e developin g wor ld (Witt, 1982, p. 301).
Wh er e w a ter su pply is low a n d w a ter tr ea tm en t in efficien t, h u m a n h ea lth is a t its m ost
vu ln er a ble poin t (Fea ch em , 1983). Th e con cer n in m a n y developin g cou n tr ies focu ses on
a su pply of sa fe a n d a dequ a te a m ou n ts of
w a ter for con su m ption a n d sa n ita r y
pu r poses. Th e Un ited N a tion s Developm en t
P r ogr a m m e (UN DP ) h a s estim a ted th a t
du r in g th e per iod 1988-1991, 70 per cen t of th e
developin g wor ld h a d a ccess to sa fe w a ter,
w ith th e figu r e dr oppin g to 45 per cen t for th e
lea st developed cou n tr ies. With r espect to
sa n ita tion fa cilities, 56 per cen t h a d a ccess
w ith a m er e 32 per cen t for th e lea st developed
cou n tr ies (UN DP, 1994, Ta ble 2, p. 132). Th ese
figu r es tr a n sla ted in 1992 to a ppr oxim a tely 1.3
billion people w ith ou t a ccess to sa fe w a ter
a n d 1.9 billion w ith ou t a ccess to pr oper sa n ita tion fa cilities (UN DP, 1994, Ta ble 3, p. 135).
Th e h ea lth im plica tion s flow in g fr om th e
fa ilu r e to su pply w a ter of su fficien t qu a lity
for dom estic u sa ge a r e tr em en dou s in developin g cou n tr ies. In a ddition to th e dir ect
th r ea ts th a t m ay flow fr om con su m ption of
w a ter con ta m in a ted by pollu ta n ts su ch a s
ch em ica l a gen ts, th e gr ea test ca u se of m or ta lity a n d m or bidity is th e spr ea d of in fectiou s
disea ses. In th e developin g wor ld th ese
a ccou n t for 72 per cen t of th e dea th s of a ll
ch ildr en u n der five yea r s old a n d 45 per cen t
of dea th s over a ll. Th e pr eva len ce of in fectiou s disea ses is dir ectly a ttr ibu ta ble to m a ln u tr ition , in a dequ a te w a ter su pply, la ck of
sa n ita tion fa cilities, poor h ygien ic pr a ctices
a n d u n sa tisfa ctor y livin g con dition s (UN E P,
1993, p. 235).
Th er e a r e five m a jor pa th w ays for w a ter r ela ted disea ses to be tr a n sm itted to h u m a n s.
F ir st, th er e a r e w a ter -bor n e disea ses wh ich
ca n a r ise fr om m u ltiple ca u ses, su ch a s th e
pr esen ce of h u m a n or a n im a l fa eces in w a ter,
u r in e in fected by ba cter ia a n d pa th ogen ic
vir u ses. Th ese or ga n ism s a r e tr a n sm itted to
h u m a n s wh en th e w a ter is u sed for dr in k in g
or food pr epa r a tion (UN E P, 1993, p. 235).
E xa m ples of w a ter -bor n e disea ses a r e
poliom yelitis, a sca r ia sis, en ter ic fever a n d
dia r r h oea l disea ses. In th e la te 1980s th er e
wer e a ppr oxim a tely th r ee billion ca ses of
th ese disea ses, pr im a r ily in th e developin g
wor ld w ith over 4.07 m illion fa ta lities, w ith
dia r r h oea l disea ses su ch a s ch oler a a n d
typh oid a ccou n tin g for fou r m illion dea th s
(UN E P, 1993, Ta ble 5.6, p. 256).
Wa ter -w a sh ed disea ses a r e ca u sed by th e
sca r city of w a ter, wh ich r en der s clea n lin ess
difficu lt to a tta in . Th is ca te gor y in clu des a ll
w a ter -bor n e disea ses in a ddition to in festa tion w ith lice or m ites wh ich a r e vector s of
typh u s (N a sh , 1993, p. 26). Com m on types of
w a ter -w a sh ed a ffliction s a r e tr a ch om a a n d
leish m a n ia sis. In th e la te 1980s th ese con dition s a ffected u p to 21 m illion people in th e
developin g wor ld a n d in th e ca se of tr a ch om a
r en der ed between six a n d n in e m illion people
blin d (UN E P, 1993, Ta ble 5.6, p. 256).
Wa ter -ba sed disea ses a r e th ose in wh ich
w a ter pr ovides th e h a bita t for th e im m edia te
h ost or ga n ism s in wh ich cer ta in pa r a sites
pa ss pa r t of th eir life cycle (N a sh , 1993, p. 26).
Th e h ost or ga n ism m ay be in gested du r in g
con su m ption of fish or oth er fr esh w a ter food
or th e dr in k in g of in fected w a ter. E xa m ples of
w a ter -ba sed con dition s a r e sch istosom ia sis
a n d dr a cu n cu lia sis wh ich a ffected a r ou n d
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210 m illion people in th e developin g wor ld in
th e la te 1980s. Du r in g th is per iod, sch istosom ia sis r esu lted in a ppr oxim a tely 200, 000
fa ta lities (UN E P, 1993, Ta ble 5.6, p. 256).
Wa ter -r ela ted disea ses a r e th ose in wh ich
in sect vector s of pa r a sitic disea ses r ely on
w a ter a s a h a bita t. In th is ca se tr a n sm ission
is n ot du e to dir ect h u m a n con ta ct w ith w a ter
(UN E P, 1993, p. 235). Afr ica n tr ypa n osom ia sis,
eleph a n tia sis, on ch ocer cia sis, yellow fever,
den gu e fever, J a pa n ese en ceph a litis a n d
m a la r ia dom in a te th is a r ea a ccou n tin g for
435.04 m illion ca ses in th e developin g wor ld
in th e 1980s w ith fa ta lities r a n gin g between
on e a n d 2.05 m illion . Ma la r ia a ccou n ted for
th e bu lk of th e ca ses w ith 267 m illion a n d
between on e a n d two m illion of th e r ecor ded
dea th s (UN E P, 1993, Ta ble 5.6, p. 256).
F in a lly, th er e a r e w a ter -disper sed in fection s wh er e th e in fectiou s a gen ts th r ive in
fr esh w a ter a n d a r e in h a led in to th e r espir a tor y tr a ct w ith m in u te w a ter dr oplets.
L egion ella is a n exa m ple of a w a ter -disper sed
in fection a n d th is ca te gor y of w a ter -r ela ted
disea ses is th e on ly on e th a t a ppea r s w ith
som e fr equ en cy in developed cou n tr ies
(UN E P, 1993, p. 235).
Th e sta r tlin g sta tistics of w a ter -ba sed disea ses r ecited a bove a r e per h a ps th e tr a gic
pr oof th a t th e gr ea test th r ea t to developin g
cou n tr ies lies in obta in in g a fr esh w a ter su pply for dom estic u sa ge. With ou t u r gen t a tten tion to th is r equ ir em en t, th e lives of billion s
m ay be sim ply w a sted aw ay.
Desertification
On e of th e a la r m in g fea tu r es of th e la st two
deca des h a s been th e gr ow in g deser tifica tion
of sever a l r e gion s in th e developin g wor ld, th e
m ost n oticea ble bein g th e Su b-Sa h a r a n
r e gion . Wh ile th e loss of biologica l diver sity
a n d h u m a n su ffer in g a r e th e m ost a ppa r en t
m a n ifesta tion s of deser tifica tion , th er e m ay
even be h ea lth con sequ en ces. Cr op fa ilu r e
a n d loss of livestock often lea ds to m a ln u tr ition . Wea k en ed bodies a r e th en r en der ed
su sceptible to th e r ava ges of h u n ger a n d disea se. Alth ou gh few disea ses a r e specific to
deser tifica tion , eye disea se su ch a s tr a ch om a
a n d oth er a ffliction s lik e bilh a r zia m ay be
m or e pr om in en t u n der con dition s of deser tifica tion (Secr eta r ia t of th e Un ited N a tion s
Con fer en ce on Deser tifica tion , 1977, p. 42).
Environmental degradation and
human health: national risk
Indoor air pollution
Th er e a r e a r ea s of en vir on m en ta l a bu se th a t
give r ise pr edom in a n tly to n a tion a l h ea lth
pr oblem s. On e su ch a r ea is in door a ir pollu tion wh ich h a s r ava ged th e developin g wor ld
[ 56 ]
w ith a n estim a ted 400 to 700 m illion people
bein g a t r isk a n d a n n u a l dea th s to in fa n ts a n d
ch ildr en of a r ou n d fou r m illion a n n u a lly
(Wor ld Ba n k , 1992, p. 52). Th e m a jor pr oblem s
a r e ca u sed by n on -biom a ss a n d biom a ss com bu stion . N on -biom a ss in door com bu stion
n or m a lly per ta in s to th e u se of ga s r a n ges for
cook in g. Gen er a lly, in door ga s r a n ges do n ot
h ave a ga s exh a u st system , so a llow in g th e
ga seou s pr odu cts of com bu stion to en ter th e
in door a ir dir ectly du r in g u se (Gr eim , 1989,
p. 193). Th e two m a jor em ission s a r e ca r bon
m on oxide a n d n itr ogen dioxide.
Ca r bon m on oxide is em itted a s a r esu lt of
th e in com plete com bu stion of ca r bon a ceou s
m a ter ia l. In a ddition to ga s r a n ges, w a ter
h ea ter s a n d ga s or coa l h ea ter s a r e m a jor
in door sou r ces of ca r bon m on oxide. Ca r bon
m on oxide pr odu ces toxic effects in th e
h u m a n body. Du e to its a ffin ity to h a em oglobin it displa ces oxygen , so lower in g th e oxygen ca r r yin g ca pa city of blood. Ca r bon
m on oxide h a s its m ost toxic a cu te effects on
th e or ga n s w ith h igh oxygen r equ ir em en ts,
su ch a s th e h ea r t a n d th e br a in . At low levels,
ca r bon m on oxide ca n ca u se fl u -lik e sym ptom s especia lly in ch ildr en (Gold, 1992, pp.
216-7). At h igh levels, it ca n lea d to com a a n d
possibly dea th (Wellbu r n , 1988, p. 17). N itr ogen dioxide is a n oxida n t th a t is solu ble in
tissu es. Most in h a led n itr ogen dioxide is
r eta in ed in th e lu n gs a n d deposited pr im a r ily
in th e la r ge a n d sm a ll a ir w ays. At h igh con cen tr a tion s n itr ogen dioxide ca u ses exten sive
lu n g in ju r ies. F a ta l pu lm on a r y oedem a a n d
br on ch opn eu m on ia h ave been r epor ted a t
h igh con cen tr a tion s, w ith br on ch itis a n d
pn eu m on ia a t lower levels (La m ber t a n d
Sa m et, 1994, p. 612).
Biom a ss fu els com pr ise pr ocessed biom a ss
su ch a s ch a r coa l, m eth a n e, loggin g w a ste a n d
saw du st. Un pr ocessed biom a ss fu els a r e gen er a ted fr om sou r ces su ch a s wood, du n g,
str aw, a gr icu ltu r a l w a stes a n d ve geta ble
m a tter. Bu r n in g of biom a ss for fu el ca n r esu lt
in th e pr odu ction of pa r ticu la tes,
ben zo(a )pyr en e, ca r bon m on oxide, n itr ogen
dioxide, su lph u r dioxide, for m a ldeh yde,
vola tile or ga n ic com pou n ds a n d n u m er ou s
oth er su bsta n ces (Gold, 1992, p. 218). In th is
a r ea th e developin g wor ld a ppea r s m ost vu ln er a ble. Un for tu n a tely, except for th e wor k of
Ch en (1990), th e issu e h a s n ot been com pr eh en sively r esea r ch ed in th e developin g wor ld.
It h a s been sta ted th a t in door pollu ta n ts
m ay pose a gr ea ter h ea lth r isk in th e developin g wor ld th a n ou tdoor a ir pollu tion du e to
th e fa ct th a t m a n y people, especia lly wom en ,
spen d a lot of tim e in door s (Davidson , 1986,
p. 561). Biom a ss su pplies 14 per cen t of th e
wor ld’s pr im a r y en er gy, w ith th e developin g
wor ld a ccou n tin g for a ppr oxim a tely 35 per
cen t of th a t fi gu r e. In som e developin g
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cou n tr ies, biom a ss a ccou n ts for a s m u ch a s 90
per cen t of th e pr im a r y en er gy. Appr oxim a tely
50 per cen t of th e wor ld’s popu la tion pr edom in a n tly fr om th e developin g wor ld, r ely m a in ly
or exclu sively on biom a ss fu els to sa tisfy th eir
da ily en er gy n eeds, th a t is, for cook in g a n d
h ea tin g (UNEP, 1993, p. 273).
In developin g cou n tr ies, it h a s been sh ow n
th a t th e in ciden ce of lu n g ca n cer r ises a s a
r esu lt of exposu r e to pa r ticu la tes a n d ga seou s
em ission a r isin g fr om bu r n in g of biom a ss
fu el in wh a t a r e often poor ly ven tila ted
h ou ses. Addition a lly, th er e is a h igh er in ciden ce of ch r on ic br on ch itis in n on -sm ok in g
wom en , a n d r espir a tor y a ilm en ts a n d pn eu m on ia a m on g ch ildr en (Gold, 1992, p. 218).
Th ese tr en ds h ave been bor n e ou t in th e
in cr ea sin g n u m ber of ca se stu dies per for m ed
in developin g cou n tr ies, pa r ticu la r ly in
Afr ica a n d Asia . E xposu r e to ga seou s em ission s fr om biom a ss bu r n in g h a s been lin k ed
w ith dim in ish ed lu n g fu n ction s in ch ildr en in
Ku a la Lu m pu r, Ma laysia (Azizi a n d Hen r y,
1990, p. 26). In a ca se con tr ol stu dy per for m ed
in th e pr ovin ce of Gu a n gzh ou , Ch in a , lu n g
ca n cer em er ged a s th e m a jor ca u se of dea th
by ca n cer a m on g m en a n d wom en . Sm ok in g
a ppea r ed to be dom in a n t a m on g m a le fa ta lities bu t w ith r espect to wom en cou ld n ot h ave
been a sign ifi ca n t fa ctor, beca u se of lower
sm ok in g a ctivities. Th e r esu lts of th e stu dy
in dica ted th a t in door a ir pollu tion du e to
h om e cook in g w a s th e dr ivin g fa ctor in lu n g
ca n cer a m on g wom en wh o wer e exposed to
coa l fu m es a n d cook in g oil va pou r s (Liu et a l.,
1993). In Sh en ya n g, Ch in a , a ca se con tr ol
stu dy of 1,249 pa tien ts w ith lu n g ca n cer fou n d
th a t wh ile ciga r ette sm ok in g w a s a m a jor
con tr ibu tor y fa ctor, in door a ir pollu tion w a s
th e sign ifica n t fa ctor in th e ca se of wom en .
Th e r isk of lu n g ca n cer w a s between 50 to 70
per cen t h igh er in h om es h ea ted by coa ls or
u sin g coa ls for cook in g. Wh er e k a n g w a s u sed
for h ea tin g bedr oom s or cook in g w a s don e
w ith in close pr oxim ity of sleepin g qu a r ter s,
th e r isk w a s a t its h igh est level (Xu , 1989). In
Sh a n gh a i, th e in door bu r n in g of coa l h a s
been positively lin k ed to a h igh er in ciden ce of
str ok e a m on g m a les (Zh a n g, 1988, p. 976).
Th e gr im pictu r e in Asia exten ds to Afr ica
wh er e sim ila r r esu lts wer e obta in ed. In Zim ba bwe, in vestiga tion s h ave r evea led th a t
ch ildr en a r e m or e lik ely to su ffer fr om pn eu m on ia in h om es wh er e wood is u sed a s fu el
(L a n cet, 1992, p. 397). In r u r a l Ken ya , m ea su r em en ts of in door a ir pollu tion r evea led th a t
r espir a ble pa r ticu la tes a n d n itr ogen oxide
wer e a ppr oxim a tely ten tim es h igh er th a n th e
r ecom m en ded a ir qu a lity gu idelin es. Addition a lly, th e level of polycyclic a r om a tic
h ydr oca r bon s w a s a lso qu ite h igh (Boleij et
a l., 1989, p. 1677). A stu dy in Gh a n a h a s n oted
th e a dver se h ea lth effects on wom en a n d
you n g ch ildr en a r isin g fr om th e bu r n in g of
biom a ss fu el for cook in g. A pleth or a of r espir a tor y pr oblem s bea r s w itn ess to th e tr a gedy
of in door a ir pollu tion (McGr a n a h a n a n d
Son gsor e, 1994, pp. 4-45).
P a n dey et a l. (1989) h ave n oted th a t, in th e
developin g wor ld, th e exposu r e to h igh levels
of sm ok e fr om in door biom a ss bu r n in g w ith ou t a fl u e or ch im n ey a n d w ith poor ven tila tion is r espon sible for a cu te r espir a tor y in fection s th a t ca u se on e-th ir d of a ll ch ildh ood
dea th s u n der five yea r s. F u r th er, th e ba sic
eviden ce su ggests th a t pea k a n d da ily exposu r es to in door pa r ticu la te levels wou ld
a ppea r a t tim es to be 20 tim es gr ea ter in th e
developin g wor ld th a n th e developed (P a n dey
et a l., 1989, p. 427). On e stu dy h a s r evea led th a t
in selected developin g cou n tr ies, th e aver a ge
a n n u a l m icr ogr a m s of pollu ta n t is 300 per
cu bic m etr e of a ir in r u r a l a r ea s, w ith th e
cor r espon din g fi gu r e for th e developed wor ld
bein g 75 per cu bic m etr e of a ir (Sm ith , 1988,
p. 19).
Outdoor air pollution
Ou tdoor a ir pollu tion is a n oth er ser iou s en vir on m en ta l fa ctor th a t ca n im pa ct a dver sely
on h u m a n h ea lth . Alth ou gh it is dea lt w ith a s
a n a tion a l pr oblem , it ca n qu ite ea sily pose
tr a n sbou n da r y pr oblem s, especia lly in a r ea s
of con cen tr a ted a ir pollu tion , su ch a s th e
Bla ck Tr ia n gle in E u r ope between Ger m a n y,
Pola n d a n d th e Czech Repu blic. In deed, it is
a r gu a ble th a t ou tdoor a ir pollu tion a m on g
n a tion s w ith com m on bou n da r ies is so w idespr ea d a s to ju stify its con sider a tion a s a n
a r ea of globa l con cer n . Th er e a r e m a n y for m s
of ou tdoor a ir pollu tion a n d th is pa per w ill
focu s on ju st a few exa m ples. On e com m on
type of ou tdoor a ir pollu ta n t is r efer r ed to a s
su spen ded pa r ticu la te m a tter (SP M). SP M
r efer s to th e w ide r a n ge of fi n ely divided
solids or liqu ids disper sed in to th e a tm osph er e fr om n a tu r a l sou r ces, in du str ia l a ctivities a n d com bu stion pr ocesses. Th e com position of SP Ms va r ies bu t typica lly in clu des
ca r bon , h igh er h ydr oca r bon s for m ed by
in com plete com bu stion of h ydr oca r bon fu els,
a n d su lph u r, th e la tter of wh ich m ay a ccou n t
for u p to a ppr oxim a tely 20 per cen t of th e tota l
SP Ms (E lsom , 1992, p. 21). Th u s, th e effects of
SP Ms on th e en vir on m en t a r e h igh ly in fl u en ced by su lph u r -ba sed em ission s. Th e
h ea lth im pa ct of su ch levels of em ission s is
tr em en dou s a n d exposu r e to SP Ms h a s been
lin k ed w ith h igh er in ciden ce of a sth m a , br on ch itis a n d pu lm on a r y em ph ysem a (E lsom ,
1992, p. 27).
An oth er com m on type of a ir pollu ta n t is
su lph u r dioxide. Th is is a colou r less ga s em itted fr om sou r ces sim ila r to SP Ms. Its em ission is h igh est fr om th e com bu stion of coa l
a n d oil. Su lph u r dioxide r ea cts ca ta lytica lly
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or ph otoch em ica lly w ith oth er pollu ta n ts to
for m su lph u r tr ioxide, su lph u r ic a cid a n d
su lph a tes (E lsom , 1992, p. 22). Su lph u r is h istor ica lly r e ga r ded a s on e of th e tr a dition a l
sou r ces of pollu tion . At its zen ith , su lph u r
pollu tion h a s m a n ifested itself in th e fa m ou s
su lph u r ou s sm ogs th a t a fflicted m ost in du str ia l cities. Sm ogs a r e gen er a lly for m ed wh en
m eteor ologica l con dition s fa il to disper se
la r ge qu a n tities of pollu ta n ts em itted fr om
in du str y, veh icles a n d dom estic sou r ces. Su lph u r -r ela ted pr odu cts ca n h ave a fa ta l im pa ct
on h u m a n h ea lth a s eviden ced by th e in fa m ou s su lph u r ou s sm og th a t str u ck Lon don in
Decem ber 1952. Th e dea th of n ea r ly 4, 000
people w a s th e r esu lt w ith th e la r gest con tr ibu tor bein g br on ch itis, followed by oth er disea ses ch a r a cter ized by im pa ir m en t of r espir a tor y fu n ction s (E lsom , 1992, pp. 22-5). On a
less fa ta l ba sis, su lph u r dioxide pr odu ces a
str on g ir r ita tion on th e eyes a n d th e n a sa l
pa ssa gew ay. Mor eover, su lph u r dioxide em ission s h ave been lin k ed w ith h igh er
in ciden ces of a sth m a , br on ch itis, pu lm on a r y
em ph ysem a a n d a gen er a l r edu ction of lu n g
fu n ction s especia lly in ch ildr en (Wellbu r n ,
1988, pp. 53-6). An oth er pa r ticu la r va r ia tion of
su lph u r em ission s is h ydr ogen su lph ide. It is
sligh tly ph ototoxic a n d a t h igh levels it ca n
ir r ita te th e lu n g pa ssa ge a n d eyes of h u m a n s
possibly r esu ltin g in pn eu m on ia a n d con ju n ctivitis (Wellbu r n , 1988, pp. 182-6).
Oxides of n itr ogen a r e a lso da n ger ou s
sou r ces of a ir pollu tion . Th e pr in cipa l a n th r opogen ic em ission s of oxides of n itr ogen a r e
fr om th e com bu stion of fossil fu els in fixed
sou r ces lik e power pla n ts a n d h ea tin g, a n d in
m otor ca r s fr om th e in ter n a l com bu stion
en gin e. In developed cou n tr ies, th e oper a tion
of power pla n ts con tr ibu tes a ppr oxim a tely 45
per cen t of th e em ission of oxides of n itr ogen ,
r oa d tr a n spor t a bou t 30 per cen t, w ith th e
ba la n ce fr om dom estic a n d gen er a l in du str ia l
sou r ces (Wellbu r n , 1988, p. 68). Th e h ea lth
im plica tion s of em ission of oxides of n itr ogen
m ay n ot be a s power fu l a s oth er a ir pollu ta n ts
bu t ou gh t n ot to be u n der estim a ted. N itr ogen
dioxide is k n ow n for its stin gin g, su ffoca tin g
odou r. F u r th er, eviden ce poin ts to in cr ea sed
a ir w ay r esista n ce a n d sen sitivity to br on ch ocon str ictor s in cer ta in in dividu a ls
(E lsom , 1992, p. 49). At h igh levels of exposu r e,
n itr ou s fu m es m ay ca u se cou gh in g,
h ea da ch es a n d ch est tigh tn ess. Th is m ay lea d
to su dden cir cu la tor y colla pse a n d w a ter
a ccu m u la tion in th e lu n gs. E xcess blood
n itr a te m ay r edu ce blood pr essu r e wh ich in
tu r n cou ld ca u se destr u ction of blood cells,
liver a n d k idn ey defects (Wellbu r n , 1988,
p. 91).
P h otoch em ica l oxida n ts a lso con tr ibu te to
th e da n ger ou s cock ta il of a ir pollu ta n ts th a t
a r e pr esen t today. E va por a tion of solven ts a n d
fu els togeth er w ith th e in com plete com bu stion of fossil fu els ca u ses va r iou s h ydr oca r bon s to be r elea sed in to th e a tm osph er e (Wellbu r n , 1988, p. 135). P h otoch em ica l oxida n ts
a r e secon da r y pollu ta n ts for m ed by th e
a ction of su n ligh t on a n a tm osph er e con ta in in g r ea ctive h ydr oca r bon s a n d oxides of
n itr ogen . Th ese r ea ction s pr odu ce m a n y
oxida n ts w ith per oxya cetyl n itr a te a n d ozon e
bein g th e m ost sign ifica n t. Th e k ey to th e
for m a tion of ozon e is th e ph otolysis of th e
n itr ogen dioxide m olecu le by u ltr aviolet
r a dia tion du r in g dayligh t h ou r s. P h otoch em ica l oxida n ts in th eir sm oglik e for m a r e ca pa ble of ca u sin g eye a n d n ose ir r ita tion . Du r in g
episodes in Los An geles in Septem ber 1979, 55
per cen t of th e people su r veyed com pla in ed of
bu r n in g or ir r ita tion of th e eyes, 25 per cen t
r epor ted h ea da ch es, br ea th in g ir r ita tion ,
sor e th r oa ts or stu ffy n oses, wh ile h ospita ls
r ecor ded a lm ost a 50 per cen t a dm itta n ce r a te
in