Environmental
Contaminants

Some contaminants may cause acute poisoning and kill fish, birds, or other wildlife outright. Other contaminants may cause more subtle effects, such as reproductive or developmental problems, behavioral abnormalities, or immune system dysfunction. In these cases, individual animals often appear healthy, but the exposure to contaminants causes a long-term decline in the population.

Where do environmental contaminants come from?

Contaminants enter the environment in many different ways. Industrial discharges, oil or chemical spills, pesticide applications, improper disposal of hazardous waste, and road and parking lot run-off are just a few. In many cases the source of contamination may be difficult to determine. Some contaminants may be released into the air and later deposit many miles away from the source. Others may seep into groundwater during a spill and contaminate a stream long after the initial release.

Isn’t the EPA responsible for protecting the environment from contaminants?

Our primary goal is the protection of fish, wildlife, and their supporting habitats. In fact, we are the only federal agency specifically concerned with the effects of environmental contaminants on fish and wildlife. While FWS contaminants specialists do provide technical support to the EPA, the EPA's primary focus is human health and safety. Any benefits to fish and wildlife are usually indirect to EPA’s primary mission.