Rachel Carson’s careful citations in her book Silent Spring have been reinforced by a recent study that shows a more direct link between DDT and human cancers, contrary to claims by lobbyists, junk science purveyors and practitioners of voodoo science.
Another study suggests DDT causes damage to the reproductive organs of children of people exposed to the pesticide. The connection is again to the daughter product, DDE.
Danger appears to result from exposure in utero or from breast feeding. The Reuters India story said:
Researchers led by Katherine McGlynn of the U.S. government’s National Cancer Institute examined blood samples provided by 739 men in the U.S. military with testicular cancer and 915 others who did not have it.
The link between DDE and cancer was particularly strong with a type of testicular cancer known as seminoma, which involves the sperm-producing germ cells of the testicles.
If diagnosed, testicular cancers are among the most treatable. It generally strikes men in their 20s and 30s. About 8,000 new cases per year show up in the U.S. In an average year testicular cancer kills 380 Americans. The NCI study suggests about 15 percent of cases in the U.S. can be attributed to DDT exposure.
It is possible some of the men who later developed cancer of the testicles were exposed to DDE at very young ages — in the womb or through breastfeeding, the researchers said.
“In testicular cancer, there’s a fair amount of evidence that something is happening very early in life to increase risk,” McGlynn said in a telephone interview.
DDE remains ubiquitous in the environment even decades after DDT was being banned in the United States — and is present in about 90 percent of Americans, McGlynn said.
“The trouble with these chemicals is they hang around a long time. It’s in the food chain now,” McGlynn added. People who eat fish from contaminated areas can absorb it, for instance.
The study was published on-line in the Journal of the National Cancer Institute on April 29, 2008, ahead of print publication.
- CTV (Canada) story, with links to the Journal of the National Cancer Institute
- MLA format citation: Journal of the National Cancer Institute. “Pesticide Metabolites Associated With Increased Risk Of Testicular Cancers, Study Shows.” ScienceDaily 30 April 2008. 2 May 2008 ; more colloquial format: McGlynn, K. Journal of the National Cancer Institute, April 29, 2008: vol 100: pp 1-9
- Science Daily report on the study
- Web/MD report, “Cancer Risk Lingers for Long-banned DDT“
- Earlier Science Daily report on Yale study that will look at potential causes of the spike in testicular cancers, focusing on endocrine disruptors like DDT and its byproducts.
- NCI Cancer Trends Report, 2007 – Pesticides