CHAPEL HILL, N.C.--One of the largest, most comprehensive studies ever done of the effects of pesticide exposure on the immune systems of people living near U.S. chemical manufacturing plants and dump sites offers bad news and good news to southern Moore County residents. The bad news is that some residents whose homes are within a mile of Aberdeen pesticide sites show elevated DDE levels in their blood, according to a University of North Carolina at Chapel Hill scientist. DDE is a byproduct of the body's struggles to break down the pesticide DDT, which has been banned since 1972 for use in the United States.
"The good news is that we are not seeing major clinical effects from the exposures, based on the health indicators we investigated," said Dr. Marilyn Vine, assistant professor of epidemiology at the UNC-CH School of Public Health. "Despite the large number of pesticides contained in the dump sites, of a panel of 20 organochlorines, DDE was the only organochlorine detected in the blood of 302 study participants, with one exception.
"Levels of plasma DDE in the study population overall were low compared to nationwide levels between 1976 and 1980, just after the DDT ban," Vine said.
Younger Aberdeen residents--those between ages 18 and 40--and people who lived there before 1985 when the plants were operating did show a two- to three-fold increased risk of herpes zoster, or shingles, which indicates modest suppression of the body's immune system, the researchers found.
Most volunteers tested showed immune system indicators to be within normal ranges, however, she said.
Among people ages 40 to 59 who lived within a mile of what is called the
Farm Chemicals site before 1985, the median plasma DDE level was six parts per
billion. The median level among comparable people who moved there after 1985 was
2.7 parts per billion, which suggested heavier exposures while the plant was in
operation, as one would expect
Contact: David L. Williamson
University of North Carolina at Chapel Hill