Abstract
Pesticides are currently regulated individually but are present in aquatic systems as mixtures of toxicants. In this study, the lethal effects of three agricultural insecticides--chlorpyrifos, imidacloprid and dimethoate--on Chironomus dilutus larvae were examined. Ninety-six-hour static bioassays were performed using single, binary, and ternary toxicant mixtures. The effects of the binary mixtures were investigated using the MIXTOX model to determine if the mixtures behaved additively, synergistically, or antagonistically. Dimethoate was much less toxic than chlorpyrifos or imidacloprid. Chlorpyrifos and dimethoate were not additive in mixture despite their common mode of action (MOA) and resulted in opposing effects (synergism and antagonism, respectively) when combined with imidacloprid. Synergism was observed in the ternary mixture. These results suggest that current mixture models based on MOA alone may not always be adequate in describing mixture effects, as in the current situation of mixtures with relatively few components. Other factors, such as water solubility, secondary MOA, and mechanisms of toxicity, should also be considered in future investigations of multichemical-mixture effects.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Archives of Environmental Contamination and Toxicology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
