Skip to main content
Log in

Assessment of the Probabilistic Ecological Risk Assessment-Toxic Equivalent Combination Approach for Evaluating Pesticide Mixture Toxicity to Zooplankton in Outdoor Microcosms

  • Published:
Archives of Environmental Contamination and Toxicology Aims and scope Submit manuscript

Abstract

The probabilistic ecological risk assessment-toxic equivalent (PERA-TE) combination approach was recently introduced in response to the increased demand for risk assessment approaches that can accommodate mixtures. The effectiveness and validity of the PERA-TE approach was assessed using two types of pesticide mixtures tested in outdoor microcosms. The first type of mixture consisted of pesticides with similar modes of action (the organophosphorus insecticides chlorpyrifos and diazinon) and the second of pesticides with different modes of action (chlorpyrifos, endosulfan, and trifluralin). To assess the toxicity of, and potential interaction within, each type of mixture, theoretically equitoxic TE mixtures were prepared in different proportional ratios. The TE mixtures were based on the 10th centile of acute toxicity effects distributions (data obtained from the literature) and a factor of the sum of the 90th centile field concentrations extrapolated from exposure distributions based on North American surface water monitoring data. Changes in zooplankton population abundances were used as the effect measure. The binary organophosphorus mixtures were equitoxic and conformed to the concentration addition model. The observed response trends of zooplankton exposed to the mixture of chemicals with different modes of action were a result of the susceptibility of individual taxa to the dominating pesticide in each mixture. Overall, the PERA-TE approach was not effective in predicting the toxicity and interaction of all mixture types and should be limited to assessing mixtures of chemicals with similar modes of action.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

George, ., Liber, ., Solomon, . et al. Assessment of the Probabilistic Ecological Risk Assessment-Toxic Equivalent Combination Approach for Evaluating Pesticide Mixture Toxicity to Zooplankton in Outdoor Microcosms. Arch Environ Contam Toxicol 45, 453–461 (2003). https://doi.org/10.1007/s00244-003-2123-9

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00244-003-2123-9

Keywords

Navigation