Overview of USGS research on emerging contaminants

Chemicals of emerging environmental concern, sometimes referred to as emerging contaminants (ECs) include a wide range of chemicals used in our home and businesses. Many are key ingredients to public health and quality of life. It is important to study these chemicals comprehensively because: (1) they are found to co-occur in common environmental settings, and (2) they may interact in a manner that affects living organisms.

These ECs can be concentrated in the waste stream and enter the environment via a wide range of source pathways, including wastewater treatment plants, on-site septic systems, animal waste releases, and land application of biosolids and manure. They are found commonly in complex low-level mixtures in streams and wells. Although some ECs have been found to have adverse ecological health effects, information is limited in both species and chemicals tested, and knowledge of effects of chronic exposure to the low-level mixtures found in the environment is virtually nil. Furthermore, sparse data on drinking water indicate reduction or removal of many ECs, but some persist.

Research challenges include: evaluating environmental settings where levels may be elevated, assessing potential effects of exposure of nontarget organisms (especially sensitive species and subpopulations), evaluating the performance of alternative wastewater and drinking water treatment technologies, and characterizing in more detail potential human exposure through public and domestic water supplies. In addition, systematic research on the highest priority chemicals and environmental settings is warranted so as to inform further decisionmaking and guide future research.