Toxic Pollution: Toxic chemicals are chemical contaminants that harm plants, animals, fishes and humans. Zinc, copper, and other metals, occur naturally in the Bay and its tributaries and do not pose a threat, but some chemicals accumulate in sediment at the bottom of the Bay, in animal tissue, in the water column, and reach levels that are very dangerous to the Bay's organisms
Scientists have pointed out that any large body of water will never be completely free of chemical contaminants, but certain types and levels of chemicals found in water bodies can affect the reproduction, development and, ultimately, the survival of living resources and organisms. The toxint level of a chemical depends on many factors, including amount per area, chemical, and physical form, as well as persistence of the chemical. The chemical and physical properties of the water body, combined with the type and life stage of the living resources exposed to the chemical, also affect a contaminant's toxicity.
Sources Of Toxins****: Chemical contaminants enter the Bay and its rivers from natural processes, such as the weathering of rock, and human activities, such as manufacturing and driving. Like nutrients, chemical contaminants enter the Bay from both point and non-point sources:
Point sources, such as industries and wastewater treatment plants that discharge wastewater directly into local waterways. Although these discharges are easier to manage and regulate, they are not always the biggest source of chemical contaminants to the Bay and rivers.
Non-point sources, such as urban and suburban storm water runoff, are significant sources of chemical contaminants because they carry residue from many outdoor products, including automobile emissions and pest control substances, that reach local storm drains. These types of pollution are difficult to control.
Air Pollution, is also a source of chemical contaminants in the Bay and its rivers.