Meeting Abstract
Atrazine is a heavily applied herbicide in the United States to control the growth of broad-leaf weeds. After application, atrazine enters local waterways through seepage or run-off. Atrazine concentrations in the environment have been recorded above 300 ppb and these high concentrations are known to persist for more than 21 days. Crayfish are an ideal bioindicator of environmental contamination because they display quantifiable responses to sublethal concentrations of contaminants. In order to examine the effects of atrazine on non-target aquatic organisms, we exposed crayfish to environmentally-relevant (80 and 300 ppb) and control concentrations (0 negative control) and 1000 ppb ATR (positive control) for 15 days. Following exposure, we removed the hepatopancreas (digestive gland) and examined DNA damage using comet assays and cytochrome P450 activity levels using an enzyme-linked immunosorbent assay. We found that exposure to atrazine caused increases in the number of cells that have comets, as well as an increase in the size of the comet tails. Further, significant induction of cytochrome P450 occurred as atrazine concentration increased. Overall, we found that environmentally-relevant atrazine exposure caused cellular-level changes in hepatopancreas of crayfish. If health is interrupted in crayfish species, the physiology of other species (e.g. fish) may also be declining due to exposure to these herbicides. Moreover, research on DNA damage and cytochrome P450 activity will have applications for humans, especially for determination of safe levels of atrazine in drinking water. This work significantly increases our knowledge about the non-target effects of ecologically-relevant concentrations of atrazine.
