Contaminants of Emerging Concern

medicine bottles

Many chemicals (e.g., pharmaceuticals, flame retardants) can help people and animals live easier, healthier, and safer lives, but their use sometimes comes with unknown consequences for human and environmental health. Accidental poisonings of people and animals, drug misuse and abuse, contamination of drinking water, unintended impacts on wildlife and plants, and wasted healthcare dollars have all been associated with contaminants of emerging concern (CECs).

CECs, also known as emerging contaminants, are substances found at low levels in the environment, but impacts on humans and aquatic life are unknown. These may be new chemicals or materials just recently found in the environment, due to improvements in detection techniques. Pharmaceuticals, personal care products, and endocrine disrupting chemicals (i.e., BPA, flame retardants) are the most well-known CECs. Research on CECs is key to ensuring healthy water resources—to determine ecosystem and human health effects, detectable and safe limits, and prevention and remediation techniques.

Studies in the U.S. have identified CECs in rivers, lakes, coastal waters, groundwater, sewage sludge, landfill leachate, soil, air, and plant and animal tissues. Most of these CECs have not been fully evaluated for the risks they might pose to the environment, to plants, fish, wildlife—or to us—but research to prevent the release of CECs and mitigate their effects is ongoing, and is a quickly-growing area of interest.

For some CECs like microplastics and pharmaceuticals, it is important to understand that a major source of pollution may be people and their practices. We may unknowingly pollute because we are simply unaware that our behavior has environmental consequences, there are barriers and incentives that lead us away from environmentally sustainable options, or we are uninformed about the alternatives. This is why understanding the environmental impacts of consumer and industrial products—including how those products are made and disposed—is integral to protecting human and environmental health.


Types of Contaminants of Emerging Concern

The information below provides an overview of the different categories of contaminants of emerging concern, examples of chemicals found within those categories, where various CECs have been detected, and the health effects found in both environmental and lab-controlled studies. Click on any reference to be taken to the full citation.

This is an overview of CECs and is not intended to be a comprehensive review. For more information about any of the studies cited here, or to report an error, please contact Sarah Zack.1

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1 Date of last update: November 30, 2018.

2 This list is not meant to be inclusive of every example, but rather to give the reader an idea of what types of compounds might be found in this category.

3 Surface waters include all types of water bodies on earth, including rivers, streams, creeks, lakes, and oceans.