The environmental toxins we are exposed to everyday are now polluting our water and air. Many of these contaminants do not readily break down and some can bioaccumulate, or build up in organisms as they move up the food chain. Small marine animals are exposed to toxins by different means, such as food intake, respiration and skin contact. These toxins can then build up in the smallest animals, which are then eaten by larger animals, and so on via the food chain. Eventually, the toxins are consumed by humans and the human accumulation begins. Some examples of environmental toxins that have bioaccumulated include:
- DDT, a man-made chlorinated pesticide, was initially used during WWII to control diseases, but then became the pesticide of choice to control mosquitoes. In the USA DDT was banned in 1972 because of ecological damage to the environment and to humans.
- Mercury (heavy metals), a naturally occurring element is found as a contaminant in air, water and soil, and has been used as a preservative in pharmaceutical products and other applications. Mercury is a major contaminant from coal burning and is released from the stacks of coal burning power plants, as well as the sludge that remains after coal is burned. Once in the air, mercury settles in the water in which it is changed to methylmercury by organisms. Methymercury is highly toxic and accumulates in fish and eventually humans.
- Polychlorinated Biphenyls (PCBs), another man-made chlorintated organic compound was originally used in the production of electronics (tv’s, fluorescent lighting fixtures, refrigerators, etc), plastics, oil-based paint. PCBs were banned in 1979 due to its toxicity, including cancer, as well as its persistence in the environment. Like many persistent organic pollutants (POPs), PCBs have been found to bioaccumulate in the environment.
According to the Monterey Bay Aquarium, humans have removed as much as 90% of predatory fish such as sharks, swordfish and cod due to overfishing. Visit the link below to find best fish choices for the northeast area. http://www.montereybayaquarium.org/cr/cr_seafoodwatch/content/media/
Also visit the National Institute of Environmental Health Sciences - NIH (www.niehs.nih.gov/)