Risk Reduction Strategies to Reduce the Exposure to Chemicals of Mutual Concern

Healthy Communities and Ecosystems

Scientists have determined that certain harmful chemicals remain in the environment for a long time without breaking down. These chemicals build up in the environment and humans through the food chain because plants and animals accumulate these chemicals in their tissues. It is not unusual for fish from the lakes, rivers and oceans of North America, even in pristine areas, to be contaminated with these chemicals, to the point that their consumption can be harmful for people and wildlife. Meat, dairy products and human breast milk can also be contaminated.

In 1995, Canada, Mexico and the United States established a chemicals management program through the Commission on Environmental Cooperation (CEC) to reduce the risks of chemicals to human health and the environment in North America. This project focuses on harmful substances that persist and build up in the environment and food. The pesticides DDT, lindane and chlordane, as well as polychlorinated biphenyls (PCBs) and mercury have been the focus of significant trinational work. These chemicals are of mutual concern because of the risks that exposure to them can pose to human health, which include effects on the nervous system, the reproductive system and child development. CEC-facilitated projects have assisted in reducing these risks. Current projects target a limited set of substances, as follows.

Dioxins and furans are toxic, persistent, and bioaccumulative chemicals that are found in very small amounts in the environment, including air, water and soil. Exposure to these substances has been associated with a wide range of adverse health and environmental effects. Dioxins and furans are byproducts of the combustion of garbage, wood and other fuels and can also be generated by some industrial processes. The CEC is working to understand how much of these chemicals is present in the environment, foods and humans, as well as where they come from and how they are transported. This work also includes an examination of strategies and the preparation and dissemination of information on reducing the risks of exposure.

Mercury is a powerful neurotoxicant that can harm humans and wildlife through the inhalation of its vapors or by consumption of mercury-containing fish. While mercury occurs naturally in the earth’s crust, human activities such as mining and coal combustion release mercury into the environment. Building on extensive and comprehensive work on mercury, the CEC will develop a new trinational mercury management strategy that will explore ways to safely manage and store mercury wastes.

Flame retardants are chemicals used in plastics, foams and other products to reduce fire hazards. One group of these chemicals, known as polybrominated diphenyl ethers (PBDEs), persists in the environment and is suspected of causing deleterious health and environmental effects. CEC-sponsored work will help identify the sources, fate and effects of PBDEs being released into the environment and identify alternative for use in small and medium-size manufacturing facilities in Mexico, as well as strategies to keep these chemicals out of the recycling stream.