Residential applicator exposure assessment
14.8.2. Risk assessment of residential exposures to chlorpyrifos
Chlorpyrifos is an organophosphorous insecticide that causes toxicity by inhibiting AChE in both insect and mammalian nervous systems. The EPA completed a comprehensive chlorpyrifos exposure and risk assessment in 2000 EPA, 2000d. The patterns of use most common in indoor environments for control of pests were crack-and-crevice or spot applications and general surface treatments. Chlorpyrifos applied in homes by these methods vaporized after application, contaminated indoor air and led to secondary inha- lation exposure. Secondary dermal exposure was most likely from general surface treat- ments, leading to incidental exposures, especially among children. The effect that was considered adverse by the EPA, which was common to all exposure routes, was inhibi- tion of cholinesterases not only AChE. An AEL equal to 1000 was considered acceptable, because it took into account what was considered to be young animals’ greater sensitivity to the toxic effects of chlorpyrifos. It should be noted that most residential exposure assessments done for chlorpyrifos were Tier 1 assessments. SOPs and Pesticide Handlers Exposure Database PHED data were used in these evaluations. For a few scenarios, studies were available on environmental and biomonitoring, enabling the EPA to refine some of the exposure values.14.8.2.1. Residential applicator exposure assessment
Three residential applicator exposure assessment scenarios were evaluated: 1. paint-brush applications to surfaces 2. spot treatments with low-pressure hand sprayers 3. outdoor hose-end applications to lawns and shrubs. Residential applicator data were unavailable, and the following assumptions were taken into consideration in performing the assessment. • Dermal and inhalation exposures were combined, because cholinesterase inhibition was the toxicological end-point of concern in both cases. • The average BW of an adult is 70 kg. • The application of chlorpyrifos is made according to the label directions. • Applicators wore short-sleeved shirts and no gloves. • Exposure is short-term one day to one month after application. • When data were unavailable, surrogate unit exposures were based on PHED data. • The AEL is 1000. The daily dermal dose, inhalation dose and total MOS are defined as follows. Pesticides: risks and hazards 518 magnitude of exposures by the principal routes and their significance in the light of patterns of application use, we provided below examples from EPA exposure evaluations and the public literature. In these evaluations, residents who apply pesticides are called handlersor applicators , while non-applicator housing residents are called residential bystanders. Quantifying exposure to pesticides from the oral, inhalation, and dermal routes is essen- tial to risk characterization and management. The margin of safety MOS is defined as the ratio of the NOAEL, derived from relevant toxicity studies, to the actual estimated, calculated or measured exposure. An acceptable exposure level AEL is a MOS derived by dividing NOAELs by factors, called uncertainty factors or safety factors by different bodies, that are applied to overcome uncertainty. This chapter uses the term uncertainty factor UF. AELs are identified as such because the uncertainty factor has been applied and represents a benchmark regulation based on the level of human health concern. A MOS calculated from actual data is referred to as MOS in this chapter. Note that the EPA uses the term margin of exposure MOE instead of MOS. Also, it uses MOE UF instead of AEL. When performing risk assessments, uncertainties arise from the possibility of differen- ces in toxicological responses between people and test animals interspecies responses, differences within the human population intraspecies responses and, where applicable, within subgroups of human populations. UFs are applied to account for these differen- ces, in the absence of evidence to the contrary, as follows. • People are assumed to be 10 times 10x UF more sensitive to the adverse effects of a pes- ticide than tested animals. • An additional 10x UF is added to account for human intraspecies responses. In the United States, an additional factor known in the United States as the Food Quality Protection Act FQPA factor is added by default, assuming that if not otherwise demonstrated children are 10 times 10x UF more sensitive than adults to the adverse effects of pesticides. If all three UFs are applied, multiplying them together yields an AEL for residential set- tings equal to 1000, and this AEL is used often in the United States for Tier 1 risk assess- ments. AEL values less than 1000 may be used if data exist to refine the assessment. An AEL of 1000 means that it is only acceptable to allow a person to be exposed daily to a pes- ticide amount that is 1000x less than the level at which no adverse effects were observed in laboratory animals – that is, the AEL is 1000 or more. Therefore, an acceptable AEL may range in value from 100 to 1000 or more, depending on the amount and quality of toxicity and exposure data available to refine the risk assessment. Chlorpyrifos and pyrethrin exposures and risks, as assessed by the EPA, are described below EPA, 2000d, 2006b. For these compounds, the acute and sub-chronic toxicity end- points are described in Table 14.2. Public Health Significance of Urban Pests 52114.8.2.4. Incidental hand-to-mouth oral exposure
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» 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
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