Two canals in Michigan are dangerously contaminated with polychlorinated biphenyls, or PCBs, according to this advisory. The seriousness of the contamination was underscored by the Michigan Department of Health when it wrote in the advisory that the PCB levels were 2,000 times higher than those typically seen in fish taken from Lake St. Clair. The advisories cover the bottom feeders -- carp and catfish. That’s because they feed closest to the contaminated sediments and have high concentrations of body fat to store the PCBs. The canals affected are the Lange and Revere off Lake St. Clair. Residents who live along the canals are concerned about how long it’s taking to find the source of the contamination. The Environmental Protection Agency has been sampling and cleaning up problem areas for years but hasn’t been able to determine just where the contamination originated. PCBs have been linked to cancer and are a persistent pollutant, meaning they accumulate in the environment and in the tissues of living things.

Water well contamination in Stamford, Conn., is raising the specter that there may be extensive contamination of wells throughout the state, according to this article. Private water well testing in the city has revealed 31 percent of those tested are contaminated with chlordane and dieldrin, two pesticides banned a long time ago.

A representative of the state’s department of health said her department thinks the problem is more widespread than just Stamford. Other communities, however, are not responding to calls for testing within their jurisdictions. Some believe that’s because of funding issues and the effect on property values if the pollution is found.

Of the 628 wells tested in Stamford, 195 had levels of the pesticides, and 108 exceeded the action levels established by the state. There are another 5,000 private wells in Stamford, and that is raising concerns about how many people are potentially being exposed to the chemicals over long periods of time.

Chlordane and dieldrin were usually used to control insect pests on crops and to control termites. People are exposed to the chemicals when they drink or bathe in water containing them. People can install whole house water filters to take care of the problem. Health officials point out that the levels of the pesticides can fluctuate, so unless regular sampling is taking place, it’s not possible to know just how much exposure people are getting.