The issue of water quality in the Delta has become increasingly important in recent years. The drought has made the water quality conditions worse, leading to several harmful algal bloom events. While we have regulations in place for certain aspects of water quality, such as salinity and mercury, there is a growing interest in developing new regulations to address the occurrence of harmful algal blooms and other unregulated chemicals that we have limited knowledge about. These chemicals, called contaminants of emerging concern or CECs, include pharmaceuticals that end up in our wastewater treatment system, pesticides and herbicides with constantly evolving formulations, and even personal care products like sunscreens. Research is actively being conducted to understand how these contaminants of emerging concern may impact both aquatic life and humans.
Studies have found that certain pharmaceuticals can cause physiological abnormalities in fish and amphibians or have adverse reproductive effects on aquatic wildlife. Studies are also looking at other ways these chemicals might alter the behavior of aquatic organisms, such as becoming more susceptible to predation or less successful at feeding.
Researchers often establish ecotoxicological thresholds for CECs so that below those thresholds, there are no substantial adverse effects on aquatic life. These thresholds become important to try to maintain concentrations below in our natural waterways.
“Overall, this body of work is struggling to keep up with the dynamic nature of the industries that are producing these chemicals, and monitoring of CECs is not something that’s routinely done,” said Dr. Larsen. “That’s why these contaminants feature prominently in […]
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