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The real contaminant here is a class of chemicals called organochlorides. You might remember them from such environmental disasters as DDT and dieldrin. Like many other chemical pesticides, though, the early childhood of the organochlorides was a blissful one. Videos of life in the 1950s are full of children dancing in the wake of trucks spraying DDT, literally playing in this shower of chemical pesticide. The man who discovered the insect-killing properties of DDT and started the modern practice of chemically-mediated pest control actually was awarded the Nobel Prize in 1939. However, organochlorides have proven to be highly resistant to breakdown, highly dispersible, and highly soluble in fat. These characteristics are important for several reasons. First, the chemicals remain active for a long time—way longer than we really want them to. Second, they can travel extreme distances—organochlorides have been discovered at both the north and south poles, where I promise that nobody was trying to keep insect pests away from anything. And third, massive quantities of them can accumulate in animal tissue—quantities much, much higher than ambient levels of the chemical. The upshot, then, is that organochlorides can have global effects that touch all types of animals for lengthy periods of time. This has been especially damaging to top predators because the concentration of organochlorides that they are exposed to is a function of the total exposure of all their prey put together. When animals like eagles, bears, and humans breakdown fat stores to be used for energy, these chemicals are mobilized into the bloodstream in much higher quantities than those found in the environment. This can result in chemical interference with various hormonal processes, metabolic processes, and processes of the nervous system, as well as the production of essential proteins. In the end, what you get is a whole lot of bald eagles with a whole lot of broken egg shells and no babies. All of this in the name of killing bugs. Recently, the bugs have started to bite back. Researchers at the University of California Riverside have isolated a microorganism capable of rapidly and efficiently degrading the chemical endosulfan. While these same organochlorides make up the bulk of chemicals that have been banned from use in the United States, a good number of them still see fairly wide application. Have you ever had a squash or a cantaloupe? Chances are whoever grew it doused it with endosulfan. Chances are also that he bought it at one of these chemical stores I was talking about before, and that this store has organochlorides leaking out of every nook and cranny. That’s where the bugs come in. These recently isolated bacteria consume and breakdown endosulfan so that they can use its constituent parts for their own purposes, namely as a source of both carbon and energy. All you have to do is unleash these guys on the old abandoned chemical store, or any other area of high organic pollutant concentration, and bing! A clean bill of health. Discoveries such as this one present a tricky dilemma for the world at large. On the one hand, this story is a boon for the idea that quality of life continually increases through scientific innovation. Using bacteria to rid polluted areas of their contaminants appears to be a safe and “natural” solution to a very messy problem. Furthermore, these little critters are a case in point for the defenders of biodiversity—the concept that we must protect all organisms, regardless of obvious aesthetic or ecological value, because they may one day surprise us and clean up the whole damn planet. On the other hand,
remember this: the practice of using synthetically produced chemical agents
to control biological entities has proved to be a messy and dangerous
business. The idea that doing the reverse won’t turn out to be equally
messy and dangerous seems unfounded. In addition, the idea that these
microorganisms will turn out to be just as dangerous as the chemicals
that we use them to destroy seems to have escaped everyone’s attention.
“Our life of need and work forces us inescapably to use in time
things that belong to eternity,” said Wendell Berry. The exploitation
of one natural entity to control the effects of another, as he pointed
out, looks like it could be an endless cycle. |
copyright © 2002, The College
Hill Independent
last updated 03 14 03
