Effects on the immune system associated with living near a pesticide dump site

In this paper, we report results of the second phase of a larger study desi gned to evaluate the effects on the immune system of living near a Superfun d site containing organochlorine pesticides, volatile organic compounds, an d metals. Phase II was conducted to determine whether living near the site, consisting of six locations in Aberdeen, North Carolina, is associated wit h higher plasma organochlorine levels, immune suppression, or DNA damage. E ach of 302 residents of Aberdeen and neighboring communities provided a blo od specimen, underwent a skin test, and answered a questionnaire. Blood spe cimens were analyzed for organochlorine pesticides, immune markers, and mic ronuclei. Of 20 organochlorines tested, only DDE was detected in the blood of participants (except for one individual). Age-adjusted mean plasma DDE l evels were 4.05 ppb for Aberdeen residents and 2.95 ppb (p = 0.01) for resi dents of neighboring communities. Residents of 40-59 years of age who lived within a mile of any site, but particularly the Farm Chemicals site, had h igher plasma DDE levels than residents who lived farther away. Residents wh o lived near the Farm Chemicals site before versus after 1985 also had high er plasma DDE levels. Overall, there were few differences in immune markers between residents of Aberdeen and the neighboring communities. However, re sidents who lived closer to the dump sites had statistically significantly lower mitogen-induced lymphoproliferative activity than residents who lived farther away (p < 0.05). Residential location was not consistently associa ted with frequency of micronuclei or skin test responses. Although some sta tistically significant differences in immune markers were noted in associat ion with residential location, the magnitude of effects are of uncertain cl inical importance.