Ecotoxicity toolbox to evaluate water quality for recycling

Wastewater must be treated to remove harmful pathogens and chemicals before it can be released to the environment, but the cost of proving that all pollutants have been removed is prohibitive because potentially thousands of separate chemicals would have to be measured. Another problem is that classical chemistry measurement tests are sometimes not sensitive enough to be able to detect the very low levels of chemicals which still harm animals and plants. This research developed a suite of extremely sensitive in vitro cell culture tests and an in-situ laboratory test in which mosquitofish were observed when swimming in recycled treated water. These bioassays measured the effects of mixtures of contaminants and were compared with traditional chemical measurements of separate contaminants. The in vitro cell culture, in situ mosquitofish and classical chemical analyses of selected contaminants generated equivalent results and led to the conclusion that combining multiple lines of evidence into a toolbox approach for the assessment of water quality provides data which is more informative and relevant when assessing potential impacts on the environment than traditional chemical measurements alone.