Farmworker children's residential non-dietary exposure estimates from micro-level activity time series

Paloma I. Beamer, Robert A. Canales, Asa Bradman, James O. Leckie

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Farmworkers' children may have increased pesticide exposure through dermal absorption and non-dietary ingestion, routes that are difficult to measure and model. The Cumulative Aggregate Simulation of Exposure (CASE) model, integrates the complexity of human behavior and variability of exposure processes by combining micro-level activity time series (MLATS) and mechanistic exposure equations. CASE was used to estimate residential non-dietary organophosphate pesticide exposure (i.e., inhalation, dermal, and non-dietary ingestion) to California farmworker children and evaluate the micro-activity approach. MLATS collected from children and distributions developed from pesticide measurements in farmworkers' residences served as inputs. While estimated diazinon exposure was greater for inhalation, chlorpyrifos exposure was greater for the other routes. Greater variability existed between children (σB2 = 0.22-0.39) than within each child's simulations (σW2 = 0.01-0.02) for dermal and non-dietary ingestion. Dermal exposure simulations were not significantly different than measured values from dosimeters worn by the children. Non-dietary ingestion exposure estimates were comparable to duplicate diet measurements, indicating this route may contribute substantially to aggregate exposure. The results suggest the importance of the micro-activity approach for estimating non-dietary exposure. Other methods may underestimate exposure via these routes. Model simulations can be used to identify at-risk children and target intervention strategies.

Original languageEnglish (US)
Pages (from-to)1202-1209
Number of pages8
JournalEnvironment international
Issue number8
StatePublished - Nov 2009


  • Children
  • Chlorpyrifos
  • Dermal exposure
  • Diazinon
  • Exposure assessment
  • Farmworkers
  • Micro-activity approach
  • Non-dietary ingestion exposure
  • Organophosphate
  • Pesticides
  • Time series

ASJC Scopus subject areas

  • Environmental Science(all)


Dive into the research topics of 'Farmworker children's residential non-dietary exposure estimates from micro-level activity time series'. Together they form a unique fingerprint.

Cite this