Chlorpyrifos: Ecotoxicological risk assessment for birds and mammals in corn agroecosystems

K. R. Solomon, J. P. Giesy, R. J. Kendall, L. B. Best, J. R. Coats, K. R. Dixon, M. J. Hooper, E. E. Kenaga, S. T. McMurry

Research output: Contribution to journalArticlepeer-review

36 Scopus citations


A tiered risk assessment was conducted for the use of granular and liquid formulations of chlorpyrifos in corn agroecosystems in the U.S. The initial screening Tier I assessment suggested that under high-exposure scenarios the granular and some spray formulations present potential hazards to birds. Higher tiered probabilistic risk assessments were conducted separately for the granular and liquid formulations. The probabilistic assessment indicated that risk to birds from exposure to granular formulation is small and that this route of exposure would not be a significant source of mortality. Similarly, the assessment of potential exposure of birds to food items contaminated with chlorpyrifos showed that the risk from exposure via food was small, even if it was assumed that birds feed only on the treated fields. Although they have potentially greater sensitivity to chlorpyrifos, effects in nestling birds consuming food items from fields treated with granular chlorpyrifos were negligible. However, risks to young birds may be greater where the major source of food is from fields treated with liquid formulations of chlorpyrifos. A review of field studies showed that wildlife mortality incidents associated with use of either granular or liquid formulations of chlorpyrifos are not widely apparent in agroecosystems. Based on the multiple lines of evidence, we conclude that the presumption that chlorpyrifos use in corn agroecosystems will result in extensive mortality of terrestrial wildlife, particularly birds and mammals, is not supported by the scientific evidence.

Original languageEnglish
Pages (from-to)497-632
Number of pages136
JournalHuman and Ecological Risk Assessment (HERA)
Issue number3
StatePublished - Jun 2001


  • Food exposure
  • Formulation
  • Granules
  • Oral exposure
  • Population model


Dive into the research topics of 'Chlorpyrifos: Ecotoxicological risk assessment for birds and mammals in corn agroecosystems'. Together they form a unique fingerprint.

Cite this