Exposure potential Steps of pre-market risk assessment of pesticides
14.7.1. Steps of pre-market risk assessment of pesticides
The first step in the risk assessment process identifies the uses of a pesticide from its pro- posed label such as use on lawns, use on carpets and crack-and-crevice treatment and how it is applied such as powder, spray or fogger. In the second step, the pesticide’s toxi- city is studied. The regulatory agency determines the most sensitive effect – the so-cal- led critical effect – for each exposure route and for several exposure durations such as acute and chronic. Next, all appropriate exposure scenarios are determined. Examples of scenarios include: • person spraying a liquid pesticide • person living in a house treated for insects. A registrant may be required to conduct exposure studies that address specific exposure scenarios for a specific chemical. If an exposure study that addresses a specific exposure scenario has not been conducted and a bridge to the existing use pattern is found unac- ceptable, scientists will use a model to evaluate available data, published literature, or some other source of information to develop a risk assessment for that scenario. A different modelling approach focuses on those exposed to pesticides who have not directly used them – that is, secondary exposures of bystanders. The premise of this model is that exposure levels are related to one’s activity while in a previously treated area and to the amount of pesticide available to the individual in that environment.14.7.1.1. Exposure potential
Potential exposures may be measured or modelled, and each approach has advantages and disadvantages. Exposure measurements represent precise observations for a limi- ted number of cases: they can be carried out in the workplace, in the residential envi- ronment or through laboratory or workshop studies. Modelled exposures can be esti- Pesticides: risks and hazards 508 been assessed separately. As an exposure route, ingestion is currently weakly defined, though it may be the most important route in some circumstances. This is particularly true where inhalation and dermal uptake are low, where contaminated hands are not properly washed at the end of an application poor hygienic practice or where children have secondary exposure. A special case occurs when foodstuffs or food containers or plates and glasses are inadver- tently contaminated by spraying or direct contamination. Children spend a substantial part of their time walking and toddling indoors. Ingestion may occur by hand–mouth contact or by object–mouth contact. Such contact may be most prominent in young children, who show extensive mouthing behaviour around 1 year of age, when teeth erupt. Also, such contact transfers, to the mouth, pesticide residues, that have accumulated on hands or on objects. These may have come in contact with pesticide residues on such indoor surfaces as carpets, countertops or hard flooring or on lawns or other outdoor surfaces, such as soil. Oral non-dietary ingestion may be particularly important for infants and children exposed to lawn chemicals and household pesticide products in residential settings, because of the incidence of hand-to-mouth activity Hawley, 1985 or object-to-mouth activity Reed et al., 1999 and because of the activi- ties performed by children such as crawling that put them in close proximity to treated surfaces Cohen Hubal et al., 2000. Some assumptions and observations have been made for hand-to-mouth activity in children Reed, 1998; Zartarian, Ferguson Leckie, 1997, 1998; Zartarian et al., 2000; Tulve et al., 2002. Exposure from non-dietary ingestion may be estimated using residue data for the media of interest such as turf, soil or indoor surfaces and standard ingestion rates, based on the age group or activity of interest. Non-dietary ingestion can be assessed by using data on transferable residues for the surface area of the hands of children and also using stan- dard assumptions about the frequency of hand-to-mouth and object-to-mouth activity. The mass of residue ingested may be calculated for various age groups as the product of the transferable residue concentration in mgcm 2 , frequency of hand-to-mouth or object-to-mouth activity in eventsday, and contacted surface area from which residues are ingested in cm 2 event to yield the potential dose in mgday from hand-to-mouth transfer. Depending on the scenario of interest – that is, indoor or outdoor – dislodge- able residues should be assessed PMRA, 1998. Quantifying the intake rate from hand-to-mouth exposure is very difficult. Intake values have only been established for soil uptake, based on data collected in soil contamination study assessments that used chemical markers, although data specific to biocides have not been reported EC, 2002.14.7. Pesticide exposure and risk assessment
Parts
» TAP.COM - PUBLIC HEALTH SIGNIFICANCE OF URBAN PESTS - WHO/EUROPE - WORLD ...
» Risk of developing allergic sensitization
» Risk factors for developing asthma
» Public health impact of urban asthma
» Dust sampling Airborne sampling Comparison of various methods of allergen exposure assessment
» Cockroach sensitization and asthma
» Size characteristics of airborne mouse and rat allergens Residential exposures
» Dust mites Studies examining thresholds of exposure relevant to disease
» Cockroaches Rodents Studies examining thresholds of exposure relevant to disease
» Comprehensive avoidance of dust mite allergens Multifaceted primary prevention studies
» Limited avoidance of dust mite allergens
» Targeting housing conditions of high-risk groups
» Smokybrown cockroach American cockroach Oriental cockroach
» Brownbanded cockroach Allergy and asthma overview
» Food contamination and disease transmission
» Cost of control and management
» Impact of poverty Cockroaches
» Public costs 1. Cost of health-related conditions
» IPM of cockroaches Cockroaches
» Baits Cockroach control: pesticide applications
» Alternative strategies Cockroach control: sanitation practices
» Biological control Conclusions Cockroaches
» Origins and natural history Habitats within the home
» Food Limiting factors Distribution in Europe and N orth America
» CEH Distribution in Europe and N orth America
» The building envelope Impact of building construction
» The ventilation and heating system
» Furniture and furnishings Overall effect of the housing environment on health or illness
» Sampling methods Dust mite and allergen inspection and detection methods
» Mechanical solutions Modifying environmental conditions
» Washing Dusting Dry cleaning Vacuuming
» Home disinfectants Electric blankets Bed heaters Freezing
» Sunlight Steam cleaning Cleaning
» Autoclaving Steam cleaning Temperature control
» Barrier fabrics Temperature control
» Habitat modification Carpets Physical control methods
» Soft furnishings Air filters
» Anti-allergy sprays Antimicrobial treatments Dehumidifiers
» Pesticides Building construction Methods of house dust mite control
» Control methods Medical practitioners Other
» Background Biology and bionomics
» Other species of Cimicidae that can affect people
» Evidence of resurgence in N orth America
» Future prospects Resurgence of bedbug populations in Europe and North America
» Importance as pests Economic impact Bites and health effects
» Conducive environmental conditions An integrated approach to bedbug management
» Physical removal Exclusion Physical removal and exclusion
» Inspection Detection Inspection, detection and education
» Heat Cold Controlled atmospheres
» Use of pest management products
» Benchmarks for success in bedbug management Conclusions
» Introduction Flea biology Fleas
» Health risk and exposure assessment
» Cost for control and management
» Cost of health-related conditions
» Flea exclusion and physical removal Pesticide applications for flea control
» Foggers General surface treatments IGRs
» On-animal products Conducive environmental conditions
» Pharaoh ant biology Overview of biology and distribution in Europe and North America
» Health hazards 1. Pharaoh ant infestations: pathogen transmission and contamination
» Pharaoh ant distribution and population monitoring
» Fire ant population assessment and monitoring methods
» Fire ant geographic range and potential expansion Fire ants: stinging incidents
» Fire ants: cost of eradication
» Physical exclusion Residual contact insecticides
» Insecticidal baits Fire ants: cost of health-related issues, control and management
» Efficacy of management practices
» Implementation of fire ant control programmes
» Confirmation. Determine where control is needed.
» Fire ants Emerging problems and policy options
» Introduction Biology and bionomics of filth flies in Europe and North America
» N uisance Health hazards 1. Diseases
» Myiasis Health hazards 1. Diseases
» Pesticide applications for fly control Granular baits
» Fly exclusion practices Crack-and-crevice treatments Biological control
» Ultraviolet light traps Sticky traps Jar or bag traps Window traps
» Attractants Perimeter treatments Fly management
» Togaviridae: genus Alphavirus Viruses
» Orthomyxoviridae: genus Orthomyxovirus Bacteria
» Coxiellaceae Anaplasmataceae Spirochaetaceae Bacteria
» Regular nonsporing Gram-positive rods Mycobacteriaceae
» Microsporidia Babesiidae Eimeriidae Protozoa
» Zoonoses and sapronoses of wild birds in the urban ecosystem
» Monitoring and surveillance Management implications 1. Benchmarks
» Techniques for dispersing birds in cities
» Control of wild and feral birds in urban areas
» Economic impact of wild urban birds on human health and of controlling birds
» Introduction Human body lice
» Biological factors Implications for public health
» Louse infestation in Europe and North America
» Physical removal Pesticides Louse management 1. Inspection and detection
» Socioeconomic influences Conducive environmental conditions
» Benchmarks for lice management
» Introduction Ticks of Europe and North America
» LB in Europe and N orth America
» Geographical distribution Lyme borreliosis
» Public health impact of TBE in Europe
» Geographical distribution Geographical distribution Epizootiology and epidemiology
» HME HGA Crimean-Congo haemorrhagic fever
» Boutonneuse fever Rickettsia helvetica
» Clothing Tick removal Clothing impregnation Vaccination
» Host-centred methods Habitat manipulation and urban design
» Tick and tick-borne disease surveillance IPM
» Public activities Pesticide applications
» Surveillance and management Research
» Other mosquito-borne viral infections that cause encephalitides
» Malaria Mosquitoes as a pest nuisance
» Dengue haemorrhagic fever and yellow fever
» Dirofilariasis The spread of mosquitoes and mosquito-borne pathogens
» National reporting and Mosquitoes
» Mosquito control and management
» Sanitation and water management
» Adulticiding Larviciding Mosquito monitoring
» Use of predators biological control Passive protection
» Genetic control and transgenic mosquitoes
» Feeding Biology of commensal rodents 1. Description and natural history
» Reproduction and life cycle of commensal rodents
» Behaviour relevant to control
» Movement Biology of commensal rodents 1. Description and natural history
» Population growth and socialization of commensal rodents
» Sewers and drains Association with urban infrastructure 1. Rodents in housing
» Case study 1 – rat bites in Philadelphia: identifying the factors contributing to risk
» Zoonoses of mice Public health risks in urban areas
» Case study 2: Fairhill case study
» Tree squirrels Types, distribution and abundance
» Chipmunks Ground squirrels, antelope ground squirrels and prairie dogs
» Hamsters Voles Types, distribution and abundance
» Beavers Types, distribution and abundance
» Rabbits and hares Types, distribution and abundance
» Francisella tularensis Major rodent- and lagomorph-related bacterial and rickettsial agents
» California group viruses primarily La Crosse virus CTF virus
» Yersiniae Major rodent- and lagomorph-related bacterial and rickettsial agents
» Borrelia burgdorferi s.l. Tick-borne relapsing fever borreliae
» Toxoplasma Toxocara Major rodent- and lagomorph-related parasitic agents
» Babesiae Leptospirae Major rodent- and lagomorph-related parasitic agents
» Bartonellae Rat-bite fever agents
» Flying squirrels Ground squirrels and antelope ground squirrels
» Tree squirrels Voles and other microtine rodents
» Chipmunks Disease associations with particular types of rodents
» Beavers Disease associations with particular types of rodents
» Rabbits and hares Old World mice
» Dormice N ew World rats and mice
» Introduction The impacts of anthropogenic transformations
» Risk factors for rodent- and lagomorph-related diseases Public health impact
» Costs, control and management of infestations
» Control and management of non-commensal rodents and rodent-related diseases
» Conclusions Non-commensal rodents and lagomorphs
» EU community-level authorization of technical grade active ingredients
» Acute toxicity The precautionary principle
» The substitution doctrine Special considerations given to children’s health
» Toxicity end-points Pesticide hazard identification
» Long-term effects Pesticide hazard identification
» Insecticide synergists N eonicotinoid insecticides
» Spot applications Primary exposure of non-professional users and secondary exposures
» Inhalation Routes of exposure
» Incidental oral exposure Routes of exposure
» Exposure potential Steps of pre-market risk assessment of pesticides
» Tiered approaches to exposure estimation: a basis for risk assessment
» Mathematical mechanistic models Empirical models Some existing models
» Statistical mathematical models SOPs and exposure scenario types
» Comparing pesticide risks from residential and dietary exposures
» Residential applicator exposure assessment
» Toxicity end-points and MOS Residential applicator exposure
» Future actions and data development
» Identification Establishment of threshold levels
» Inspection Evaluation of effectiveness
» Develop an IPM plan Employment of two or more control measures
» Definitions of IPM An integrated approach to managing urban insects and rodents
» Case study 3 Case study 4 Case study 5
Show more