By Mitch Lex
A recent study by the Journal of Great Lakes Research has shown a vast improvement in dwindling levels of toxaphene, a harmful pesticide that has plagued the region long after it was banned in 1982. Toxaphene was used in some areas of the Great Lakes watershed in the late 1970s and early 80s, but the majority of the pesticide entered the region from the south, where it was used heavily for agriculture and was carried north by the wind.
Toxaphene breaks down slowly and accumulates in fish, sediment and other wildlife, which has allowed it to remain in the Great Lakes long after its use was outlawed. To measure the decrease of toxaphene, researchers sampled walleye from Lake Erie and lake trout from the other Great Lakes. Toxaphene levels found in lake trout in Lake Superior showed an 86 percent decrease between 1990 and 2009, while the walleye tested in Lake Erie had the lowest toxaphene concentrations of all the lakes.
Perhaps the biggest issue with high toxaphene levels is its effect on humans. The most common way that people come into contact with the pesticide is through eating contaminated fish, but exposure can also happen by breathing it in, touching it or drinking contaminated water. Toxaphene is a known carcinogen and can damage kidneys, liver and the nervous system.
While the Great Lakes region enjoys reduced levels of toxaphene, other areas might not be as fortunate. As levels in the region decrease, the toxins travel elsewhere, bringing their harmful effects with them.