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

Details

• Personal Author:
  Elgethun K ; Faustman EM ; Felsot AS ; Fenske RA ; Griffith WC ; Ramaprasad J ; Tsai MG ; Weppner S ; Yost MG
• Description:
  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. [Description provided by NIOSH]
• Subjects:
  Agriculture Air Pollutants, Occupational Air Pollution, Indoor Environmental Monitoring Insecticides Meteorology Occupational Health Particulate Matter Respiratory System Safety
• Keywords:
  Agricultural-chemicals Air-contamination Air-temperature Airborne-particles Author Keywords: Inhalation Risk Children Exposure-assessment Histochemical-analysis Inhalation-studies Insecticide-poisoning Methamidophos Organophosphorus-pesticides Pesticides Probabilistic Modeling Sprays Volatilization

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• ISSN:
  1559-0631
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 10 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  19
• Issue:
  6
• NIOSHTIC Number:
  nn:20036062
• Citation:
  J Expo Sci Environ Epidemiol 2009 Sep; 19(6):613-623
• Contact Point Address:
  Dr. Jaya Ramaprasad, Department of Environmental and Occupational Health Sciences, University of Washington, Box 357234, Seattle, WA 98195-7234
• Email:
  jaya@u.washington.edu
• Federal Fiscal Year:
  2009
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  University of Washington
• Peer Reviewed:
  True
• Start Date:
  20010930
• Source Full Name:
  Journal of Exposure Science and Environmental Epidemiology
• End Date:
  20270929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:10642b58d3f54bc2f7ccb9ab8f6d508d18ef6032d1c42426ba42f72d688e189e0802b20e102880dd720ba794f915f418e8be62777eea8a4660b9faa47322c2a2
• Download URL:
  https://stacks.cdc.gov/view/cdc/187657/cdc_187657_DS1.pdf
• File Type:
  [PDF - 484.74 KB ]