Air pollution also contributes to the contamination of waterways. Airborne pollutants include mercury and pollutants that cause acid rain from power plants, mercury and dioxin from incinerators, and nitrogen and toxic metals from cars. A vast majority of toxic waste produced by industry in the U.S. is released to the atmosphere, which can then fall into the nation's waters. Numerous scientific studies have documented, beyond a shadow of a doubt, that airborne contaminants, including toxic air pollution, are poisoning the nation's waters. These facts provide evidence that air pollution is not just an air problem, but a problem that affects our waterways as well.
Clean sediment is important because it is the base of the food chain.
If sediment is contaminated, it can be toxic to or contaminate organisms that live in the sediment, which in turn contaminate the fish that feed upon these organisms. People may then be at risk from consuming contaminated fish. The problems with contaminated sediments persist over time because dredging, propeller action, and flooding can kick up the sediments and recirculate them in the aquatic environment. Sediment contaminated with mercury, PCBs, cadmium, chromium, lead, and other pollutants is a tremendous problem nationwide. These Areas of Concern, such as the Detroit River, are toxic hotspots, usually because of a heavy concentration of contaminated sediments.