Chemical contaminants are chemicals or compounds that can potentially harm the heath of humans, wildlife and aquatic life. Toxic chemicals are constantly entering the Chesapeake Bay and its tributaries via wastewater, agriculture, stormwater and air pollution. While chemicals such as DDT and PCBs have been banned from production for years, many chemical contaminants are still widely used or persist in the environment.
There are two broad categories of chemical contaminants that can be found in the Chesapeake Bay and its tributaries: metals and organics.
Endocrine disruptors are another group of contaminants that have caused concern since recent discoveries of intersex fish in the Potomac River and other Chesapeake Bay tributaries. Evidence suggests that low doses of exposure to some human-produced chemicals may disrupt endocrine (reproductive) systems in fish and other species. Because the endocrine systems of fish are similar to those of humans, endocrine disruption in fish is an indication that these chemicals may also pose a risk to humans.
There are four general sources of chemical contaminants to the Chesapeake Bay and its tributaries:
Many chemical contaminants, including mercury, PCBs and PAHs, do not break down easily; instead, they bind to sediments and persist in the environment for many years. The Chesapeake Bay's wildlife and aquatic life are affected when toxic chemicals move through the food web in a process called bioaccumulation:
Chemical contaminants do not just impact wildlife. Humans can also experience negative health effects from eating contaminated fish. Each state and the District of Columbia issue fish consumption advisories to prevent people from unknowingly eating fish that could be contaminated.
While there are streams and rivers throughout the Chesapeake Bay watershed that have shown some evidence of chemical contaminants, three specific "regions of concern" have been identified as having significant problems:
A drop in tumor rates among brown bullhead catfish could indicate lowered exposure to chemical contaminants.
PCBs and mercury are among the most widespread toxins in our waterways, according to a new report.
Established outreach seems no match for anglers’ perceptions or community needs.
Male smallmouth bass exhibit signs of chemical exposure, raising concerns about river health.
Publication date: July 01, 2002 | Type of document: Report | Download: Electronic Version
This report represents the coordinated effort of a team of scientists from various institutes, who continue a long series of studies aimed at toxicological and chemical characterization of the Chesapeake Bay.
Publication date: January 01, 2001 | Type of document: Report
An assessment of ambient toxicity of Delaware public peninsula creeks where agriculture is the dominant land use. The assessment evaluates potential persistent impacts and potential intermittent or pulsed impacts. Three watershed…
Publication date: December 01, 2000 | Type of document: Agreement | Download: Electronic Version
This strategy commits to voluntary efforts that build on the successes of the state and federal regulatory programs and go beyond compliance /existing regulatory point and nonpoint source programs to preclude the need for costly regulations…
Publication date: December 01, 2000 | Type of document: Fact Sheet | Download: Electronic Version
Chemicals of concern include chemical contaminants identified in the 1999 Toxics Characterization that are at levels that may cause toxic impact, chemical contaminants responsible for listing waterbodies as impaired or threatened, and…
Publication date: May 01, 1996 | Type of document: Report
The primary objectives of this report are to describe the spatial patterns in the distribution of sediment chemical contaminants in Chesapeake Bay and to compare sediment chemical contaminant concentrations in Chesapeake Bay to sediment…
Publication date: March 01, 1995 | Type of document: Report
The purpose of this document is to present a geographical targeting approach for focusing chemical contaminant remediation, reduction, prevention, protection, and assessment actions within the Chesapeake Bay basin.
Publication date: July 01, 1993 | Type of document: Report | Download: Electronic Version
The Chesapeake Bay Groundwater Toxics Loading Workshop was held April 15-16, 1992, at the U.S. EPA Chesapeake Bay Program Office. Workshop participants reviewed and discussed available information on results from groundwater studies and…
Publication date: February 01, 1993 | Type of document: Report
The Chesapeake Bay Contaminated Sediment Critical Issue Forum was structured to seek a technical consensus on a series of questions related to the magnitude and extent of contaminated sediments within the Bay; and how that affects the…