Journal article
Children's inhalation exposure to methamidophos from sprayed potato fields in Washington State: exploring the use of probabilistic modeling of meteorological data in exposure assessment
Journal of exposure science & environmental epidemiology, Vol.19(6), pp.613-623
09/2009
Handle:
https://hdl.handle.net/2376/110706
PMID: 18957992
Abstract
We examined the significance of meteorology and postspray volatilization of methamidophos (an organophosphorus insecticide) in assessing potential inhalation risk to children in an agricultural community. We combined fluxes from sources and dispersion modeling with a range of possible local meteorology to create output to study the variability in potential community exposure as a result of changing temperature, wind speeds and wind directions. This work is based on an aerial spray drift study where air sampling measurements of methamidophos were made before, during and after a spray event were used to examine acute inhalation risk for children living in an Eastern Washington State community in close proximity (between 15 and 200 m) to sprayed potato fields. We compared the measured average air concentrations of methamidophos in the community to a "no observed adverse effect level" for subchronic inhalation to characterize acute and subchronic inhalation risks. The baseline estimates of inhalation exposure were below Environment Protection Agency's (EPA) level of concern based on a target margin of exposure of 300. As meteorological conditions during and after spraying influence the amount of material moving into areas where children reside we used historical meteorological data to drive model simulations that predicted likely air residue concentrations under different wind and temperature conditions. We also added variability to the decay constant and initial emission fluxes to create a 2-D simulation of estimated air concentrations in the community near the fields. This work provides a methodological framework for the assessment of air concentrations of pesticides from agricultural sprays in the absence of extended measurements, although including variability from meteorological conditions. The deterministic as well as the probabilistic risk analyses in this study indicated that postspray volatilization in the specific spray situation analyzed (methamidophos applied on potato fields in Eastern Washington) did not pose acute or subchronic risks as defined by the EPA. However, this study did not consider any pathway of exposure other than inhalation (e.g. diet, dermal, etc.) and the risk assessment should be evaluated in that context.
Metrics
3 Record Views
Details
- Title
- Children's inhalation exposure to methamidophos from sprayed potato fields in Washington State: exploring the use of probabilistic modeling of meteorological data in exposure assessment
- Creators
- Jaya Ramaprasad - Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington 98195-7234, USA. jaya@u.washington.eduMin G-Yi TsaiRichard A FenskeElaine M FaustmanWilliam C GriffithAllan S FelsotKai ElgethunSarah WeppnerMichael G Yost
- Publication Details
- Journal of exposure science & environmental epidemiology, Vol.19(6), pp.613-623
- Academic Unit
- Entomology, Department of
- Publisher
- United States
- Grant note
- 5450OH07544 / NIOSH CDC HHS 2P01ES09601 / NIEHS NIH HHS
- Identifiers
- 99900547019501842
- Language
- English
- Resource Type
- Journal article