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Why Others Care

For centuries, our ability to manufacture powerful industrial products and chemicals has been viewed as a laudable asset from the creation of the first artificial silk to the synthesis of DDT and, the more powerful, the better. However, more recently, we've come to learn that chemical potency can often be coupled with unanticipated health liabilities for both humans and nature. This is particularly true when chemicals are unleashed indiscriminately into our air and water supplies. DDT is a case in point.

DDT was regarded as the most powerful pesticide the world had ever known and was widely used for ridding South Pacific islands of malarial insects during WW II and as a delousing powder in Europe. In the 1950s, it started being used in increasing amounts in the US as a means of controlling insect and pest populations. Yet such widespread use started to have unwanted effects on other wildlife. Peregrine falcons and eagles were dying. Countless non-target but beneficial insects were perishing.

In 1962, biologist Rachel Carson Off-site Link brought these happenings to world attention by publishing the seminal work Silent Spring. Many mark Silent Spring as the beginning of the environmental movement of the late 20th century. In this landmark book, Carson describes how the profligate use of powerful pesticides like DDT was impacting countless amounts of natural life:

“Over increasingly large areas of the United States, spring now comes unheralded by the return of the birds and the early mornings are strangely silent where once they were filled with the beauty of bird song... As crude a weapon as the caveman's club, the chemical barrage has been hurled against the fabric of life.”

Her lyrical words and fact-filled testimonies against the chemical industry helped catalyze the banning of DDT usage throughout the US. Importantly, Carson also succeeded in heightening public awareness on this vital topic. Carson's chemical detective work is being carried on today by scientists working in the trenches to certify the safety of chemicals.

One major concern is the annual rate at which new chemicals are being added to the global mix. According to a 1996 Chemical and Engineering News Report Off-site Link, US chemical companies produce 10,000 pounds each of some 15,000 chemicals every year 2,800 of these at a rate of nearly a million pounds per annum and the top 50 at a combined annual rate of almost one trillion pounds. The potential dangers of this growing cocktail of chemicals are reiterated by Carpenter et al (2002) Off-site Link

“In reality, most persons are exposed to many chemicals, not just one or two and therefore the effects of a chemical mixture are extremely complex and may differ for each mixture depending on the chemical composition. This complexity is a major reason why mixtures have not been well studied.”

What may be even more sobering is that many of these chemicals find their way into our drinking water sources. A 1992-2000 survey conducted by the United States Geological Survey looked at 139 rivers and streams in 30 states (many of which are tapped for drinking water) and found that 95% of them contained treated sewage, steroids, DEET insect repellant, detergents and other persistent pollutants. Unfortunately, water treatment plants are not designed to remove the majority of such chemicals. For scientists working in the field of chemical toxicology, there's no shortage of work.


References
» Carson, R. (1962). Silent Spring. Boston: Houghton Mifflin.
 
» Colburn, T., Dumanoski, D., and Myers, J.P. (1996). Our Stolen Future. New York: Dutton.
 
» USGS (United States Geological Survey). (2002). National Reconnaissance of Pharmaceuticals, Hormones and Other Organic Wastewater Contaminants in Streams of the US, 1999-2000.
 

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