Emerging Contaminants in the Aquatic Environment Conference
May 31-June 1, 2017 | Visit ECAEC17 Website
The U.S. EPA defines pharmaceuticals and personal care products (PPCPs) as "any product used by individuals for personal health or cosmetic reasons or used by agribusiness to enhance growth or health of livestock." This definition encompass thousands of chemicals that make up fragrances, cosmetics, over-the-counter drugs, and veterinary medicines. The U.S. EPA has identified PPCPs as emerging contaminants of concern because little is known about these contaminants' impact on the environment or risks to human health when they are released into ecosystems.
PPCPs can enter the ecosystem in a number of ways (Figure 1). For example, wastewater effluents from sewage treatment plants and large animal farms have been identified to be major sources discharging these emerging contaminants into the surrounding water bodies. That is because many pharmaceuticals and supplements are made with higher concentrations of chemical compounds than the human body or animals can process. Humans and animals process the chemicals to varying degrees. In some cases, we incorporate 95% of the active ingredient. In other cases, it's closer to 5%. Either way, portions of these chemicals are unused by the body and are excreted as waste or are washed off into shower or sink drains. Also, people may dispose of their unwanted PPCPs improperly by either dumping them down the sewer or putting them into the trash. In addition to man made PPCPs, a number of hormones are naturally excreted by humans and animals. These contaminants could pose a potential risk both to the receiving ecosystems and to drinking water resources.
In fact, PPCPs have been detected in many of the lakes, rivers, and streams in the United States, though usually at very low levels (ppb or ppt). The occurrence of PPCPs in groundwater and surface water impacts the water quality and can cause a series of negative effects for aquatic species. For example, steroid hormones are highly potent endocrine-disrupting chemicals (EDCs) which, even at levels as low as nanograms per liter (10-9 g/L or ppt), can adversely affect the reproductive biology of aquatic species.
Aquatic organisms may not be the only ones affected. PPCPs in water could be taken up by plant roots and may accumulate in the edible portions of the plant. As water supplies becomes increasingly scare due to drought, climate change, and increased use, recycled wastewater for irrigation will become more common. However, using these contaminated waters for agricultural irrigation may introduce wastewater-associated antibiotics and pathogens to irrigated fields. This fact evokes concern about potential uptake and accumulation of PPCP contaminants in plants and the transfer of those contaminants up the food chain.
ISTC researchers are conducting various projects to examine the occurrence, fate & transport, and uptake into plants as well as mitigation techniques of PPCPs in the environment.