DATA COLLECTION
DATA COLLECTION
Previous studies found that personal protective
Demographic characteristics
equipment (PPE) was effective in reducing pesticide
exposure among workers. 15 Van et al. conducted a study
Operators were interview face to face by using
of the effectiveness of PPE that examined the relevance
questionnaires with to identify general characteristics
of dermal and inhalation exposure to chlorpyrifos among
of the participants, which consists of sociodemographic
pest control operators. It showed that intervention in the
characteristics, personal factors, working conditions,
form of a PPE program significantly reduced metabolites
and environmental factors at a baseline (October in urine before the onset of spraying activities. 16 –November,2015) as shown in Table 1
Although cypermethrin, benzene, and toluene
Biological monitoring
exposure via inhalation or skin contact can contribute to health symptoms. However, limited information is
Outcomes was evaluated biological exposure by
available on the effectiveness of intervention including
collecting urine samples in the intervention and control
PPE program to reduce biological exposure among
groups at baseline, first follow-up session (March
VCOs. This study aims to determine the effectiveness
2, 2016–May 3, 2016) and second follow-up session
of a chemical safety program to reduce occupational
(July 2–October 3, 2016). Urine samples were collected
exposure among VCOs in Bangkok, Thailand.
in 50 ml polystyrene tubes from the first void of the morning, transferred to a 10 ml polystyrene tube, and
MATERIALS AND METhOD
kept at -20ºC until the time of analysis. For 3-PBA
Study population
as cypermethrin metabolism, analysis methods were modified from Thiphom and Prapamontol’s method of
This quasi-experimental study was conducted in
using high-performance liquid chromatography (HPLC)
six administrative areas in Bangkok—Central Bangkok,
by used acid hydrolysis method 19 For trans, trans-
South Bangkok, North Bangkok, East Bangkok, North
muconic acid (tt-MA) and o-cresol, the Scherer and
Khungthon, and South Khungthon. Ninety-six male
NIOSH 8301 methods were used to determine the level
(18–60 years) public health VCOs were recruited and
of tt-MA and o-cresol by using high-performance liquid
met the inclusion criteria. There were 48 operators in
chromatography.
the intervention group from North Bangkok, South
Chemical safety program (intervention)
Bangkok, and East Bangkok and 48 operators in control group from North Khongthon, South Klongthon, and
The intervention program consisted of a chemical
23 Indian Journal of Forensic Medicine Toxicology, April-June 2018, Vol. 12, No. 2
safety training program that included the following:
task characteristics. To evaluate the effectiveness of the
1) two days of training about basic chemical safety
intervention program by comparing differences in the
including chemical toxicity, health hazards, chemical
mean outcomes of the intervention and control groups
safety handling, mixing and spraying 2) conducting
at the baseline, follow-up 1, and follow-up 2, a linear
medical examinations, providing information about
mixed model and repeated measure ANOVA were used.
occupational health and symptoms and diseases
The statistical significance was designated as p ≤ 0.05.
prevention 3) two days of training about proper PPE use including a fit test program and 4) providing a chemical
RESULTS
safety booklet.
General characteristics
Statistical Analysis
Table 1 shown the groups had similar
This study used SPSS v. 16 for data analysis.
sociodemographic characteristics; all participants were
Descriptive statistics of mean and standard deviation
male and close in age (p = 0.74)). The average work
were used to analyze participants’ demographics. For
experience of the VCOs in the intervention group and
measuring and comparing significant differences between
control group were 8.8 and 7.9 years, respectively (p =
the intervention and control groups, an independent
0.92). There were no significant differences between the
t-test for sociodemographics characteristics (age and
groups.
years of work experience). A chi-square was used to test for accident injury history, systematic illness, and work
table 1. Sociodemographic characteristics of the intervention and control groups at the baseline
Total
Intervention group
Control group
Age (years)
Work experience (years)
independent t-test at P-value ≤ 0.05 Table 2 shows results of the homogeneity of age
were similar in both groups (p = 0.452). The duration
group, education level, personal factors, environmental
of spraying insecticides did not differ between the
factors, working conditions, and PPE use. The
intervention and control groups (p = 0.112); each usually
characteristics were similar between the intervention
sprayed more than three hours per day. The percentage
and control groups; most participants fell in the 31
of operators spraying indoor areas was similar in both
to 40 year age group and most had graduated from
groups: 58.3 in the intervention group and 60.4 in the
secondary school (p = 0.05). There were not significant
control group (p = 0.835). Almost all of the participants
differences in the personal factors; similar numbers of
reported not using PPE while working (spraying and
participants reported smoking (p = 0.089), drinking (p
mixing): 81.2 in the intervention group and 66.7 in
= 0.77), and consuming preserved food (p = 0.112).
the control group. There was no significant difference
Working conditions in terms of the activities of spraying
between the groups (p = 0.162).
insecticide, mixing insecticide, and spraying time
Indian Journal of Forensic Medicine Toxicology, April-June 2018, Vol. 12, No. 2 24
Table 2 Sociodemographic characteristics of the intervention and control groups at the baseline
Intervention group
Control group
X 2 (df) P-value
n()
n()
Age group
Education level
Primary school
Secondary school
Do not smoke
Do not drink
Consume preserved food
Indoor spraying
Working condition
Spraying insecticide
Mixingloading pesticide
Duration spraying
Do not use
Chi-square test at P-value ≤ 0.05
ups. In contrast, the control group’s measurements had increased at both Follow-ups. For intervention effects,
Effectiveness of the safety chemical program
all metabolite in the control group were decreased
Table 3 and Figures 1, 2, and 3 present means and
significantly than control group by both Follow-up1 and
intervention effects metabolite measurements. After
Follow-up2 with p < 0.001. Moreover, the difference
intervention, means of 3-PBA in the intervention group
means for 3-PBA, tt-MA, and o-cresol were significantly
had decreased by both Follow-up1 and Follow-up2,
reduced in the intervention group compared to the
but the control group’s measurements had increased
control group at follow-ups 1 and 2, clearly indicating
at Follow-Up 1 and had decreased at Follow-Up 2.
that intervention program were successful.
For means of tt-MA and o-cresol had similar trends, in the intervention group’s metabolite measurements were decreased than the control group in both follow-
25 Indian Journal of Forensic Medicine Toxicology, April-June 2018, Vol. 12, No. 2
Table 3: Intervention effects of the chemical safety program on reducing chemical metabolites adjusted for time and time group interaction (continuous)
time
Intervention effects
Biological exposure
P- 95CI
3 PBA (ugg creatinine)
4.76 1.33 1.08 (-5.64, -3.89)
(-5.08, -2.87) 0.001
tt-MA (ugg creatinine)
14.74 6.85 9.21 (-8.57, -2.61)
(-21.19, -10.97) 0.001
O-cresol (mgg creatinine)
-122.72 (-159.21, -86.23)
37.42 70.18 (-164.66, -90.66)
For unadjusted used generalized estimating equations(GEE) with times and time interaction, Distrition=Poisson, Link = Identity