Toxicity end-points and MOS Residential applicator exposure
14.8.3.3. Residential bystander exposures
The general assumptions made for residential bystander exposures are as follows. • The average BW of an adult is 70 kg. • The average BW of a toddler is 15 kg. • The highest label rate for each use pattern was applied. • Exposures were secondary, except for indoor foggers. For residential bystander exposure, four scenarios were assessed to take into account pos- sible exposures of adults and children after applying pyrethrins: 1. dermal transfer and incidental oral ingestion after pet treatments 2. inhalation exposure 3. incidental oral exposure during and after indoor space-spray or fogging treatments 4. dermal exposure for all use patterns.14.8.3.4. Scenarios
14.8.3.4.1. Scenario 1: child exposure to pet treatments The assumptions made for post-application spray treatments of pets were as follows. • One half of a 473.5-ml spray container is used to treat each animal. • The transferable residue TR from a treated pet is assumed to be 20 of the maximum application rate for sprays. • The SA of a treated 15 kg dog is 6000cm 2 EPA, 1993. • The SEF is 50 50 of the dislodged residue of pyrethrins extracted from the fingers by saliva. • The SA of a hand put in a mouth is 20cm 2 . • The Freq of hand-to-mouth events is one per day. The daily incidental oral dose was given by the following expression: TR x SEF x SAhands x Freq. The MOS is given by the following expression: Short-term Oral NOAEL 20mgkgdayDaily Oral Dose mgkgday. An AEL equal to 100 was used. The MOS calculated for this route of exposure was greater than 300, which meant this route of exposure was not considered to be of concern. Pesticides: risks and hazards 52214.8.3. Residential exposures to pyrethrins
Pyrethrins are insecticides that interact with sodium channels, disrupting the transmis- sion of impulses along the axons. In 2006, the EPA completed a comprehensive assess- ment of exposure to pyrethrins and the risk they posed EPA, 2006b. The use patterns most common in indoor environments for control of pests were crack-and-crevice or spot applications, general surface treatments, and indoor fogging. Pyrethrins applied in homes have a very short residual life and secondary exposure scenarios were unlikely. Inhalation is the primary route of exposure and neurotoxicity is the adverse effect common to all exposure routes. EPA SOPs EPA, 1997a and PHED data were used in these evaluations. However, uncertainties in the assessment arose due to a lack of data on some consumer applicator habits and children’s exposure to pesticides. Registrant task forces performed residential studies that measured these exposures, thus enabling the EPA to perform more refined exposure and risk assessments. Due to the availability of these data, an AEL below 1000 could be used. AELs equal to 100 for residential exposures and to 300 for incidental oral exposure were adopted. Therefore, if the MOS calculated as MOS = NOAELDaily Dose was greater than 100 or 300, respectively, the exposure was acceptable.14.8.3.1. Toxicity end-points and MOS
Due to the short life of pyrethrins, only short-term exposures were evaluated. Dermal exposure was not considered a significant exposure route, but toxicity end-points were identified for the inhalation and oral routes of exposure. T he oral NOAEL was 20mgkgday, while the inhalation NOAEL was 7.67mgkgday. As already noted, neurotoxicity is the toxic effect. An AEL of 300 10 x 10 x 3 for oral incidental exposure was selected because a developmental neurotoxicity study was not available to fully cha- racterize exposure to children. An AEL of 100 was selected for inhalation exposures, because toxicity and exposure were well characterized from the data available.14.8.3.2. Residential applicator exposure
The assessment of residential applicator exposure evaluated the following application methods: aerosol cans, dusts, handheld wand sprayers and handheld trigger sprayers. The general assumptions made were as follows. • The maximum application rate was 0.1 kg pyrethrins per 92.90 m 2 . • Only inhalation exposures were assessed, because dermal and oral exposures were assu- med to be insignificant. Exposure was assumed to occur at the time of application. The inhalation MOS was calculated as NOAELInhalation Dose in mgkgday, and the AEL equalled 100. The calculated MOSs exceeded the AEL of 100. Thus, consumer applicator exposure to pyrethrins did not exceed the level of concern and were considered to be acceptable for details on the range of MOS values, see EPA, 2006b. Public Health Significance of Urban Pests 525 The daily oral dose in mgday is given by the expression: ISR x HTE x SEF x SA x Freq x EDBW. The MOS is given by the expression: Short-term Oral NOAEL 20 mgkgdayDaily Oral Dose. An AEL of 300 was used. In this assessment, hand-to-mouth transfer from treated surfaces did not present a risk of concern as the MOS was greater than 300. 14.8.3.4.4. Scenario 4: dermal exposure from applications of pyrethrins Dermal risk assessments were not required for pyrethrins, due to negligible dermal absorption and dermal toxicity. A 21-day dermal toxicity study in rabbits showed no sys- temic or dermal toxicity at the limit dose of 1000 mgkgday. Also, a human dermal pene- tration study showed absorption was less than 0.22. For pyrethrins, the comparative risk from the use patterns can be described as follows: Inhalation Incidental Oral Ingestion Dermal Exposures. T he dermal exposure presents the lowest risk and inhalation exposure the highest. However, inhalation risks are higher for children than for adults. Also, residues on pets treated with pyrethrins for control of pests present little risk to children and adults.14.8.4. Summary of examples of residential risk assessments
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
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