Daily News Archive
Study Links Ag Pesticide to Interference in Sexual Development
The U.S. Agency for Toxic Substances and Disease Registry (ATSDR) reports the following: Endosulfan affects the central nervous system and prevents it from working properly. Hyperactivity, nausea, dizziness, headache, or convulsions have been observed in adults exposed to high doses. Severe poisoning may result in death. Studies of the effects of endosulfan on animals suggest that long-term exposure to endosulfan can also damage the kidneys, testes, and liver and may possibly affect the body's ability to fight infection ATSDR says that the cancer data is inconclusive. Endosulfan is classified as an organochlorine, the family of pesticides such as DDT and chlordane.
When EPA "reregistered" or reevaluated endosulfan in November 2002, the agency wrote, "[T]here is evidence (effects observed in a submitted chronic oral toxicity study in rats) that endosulfan acts as an endocrine disruptor. However, further investigation is necessary to determine the relevance and impact of such findings on public health." At that time, the agency adopted some exposure mitigation measures but allowed extensive uses to continue.
Endosulfan is a broad spectrum contact insecticide and acaricide registered for use on a wide variety of vegetables, fruits, cereal grains, and cotton, as well as ornamental shrubs, trees, vines, and ornamentals for use in commercial agricultural settings. Total average annual use of endosulfan is estimated at approximately 1.38 million pounds of active ingredient (lbs. ai), according to EPA and registrant estimates. Crops with the highest average percent drop treated are: squash (40%), eggplant (41%), cantaloupe (31%), sweet potato (31%), broccoli (26%), pears (20%), and pumpkins (20%). Crops with the highest sales in 2001 include: cotton (14.2%), cantaloupe (13.2%), tomatoes (12.2%), and potatoes (8.15%).
Researchers evaluated 117 boys in a village where endosulfan has been aerially sprayed for more than 20 years and 90 comparable boys from a nearby village with no such exposure history. For each group, the researchers performed physical examinations and recorded clinical history, sexual maturity rating, and blood levels of various hormones. The study found a higher prevalence of congenital abnormalities related to testicular descent in the study group, but it was not statistically significant due to a small sample size.
results suggest that endosulfan exposure may delay sexual maturity and
interfere with hormone synthesis in male children," the study authors
write. "The practice of aerial spraying of endosulfan was discontinued
in December 2000. Serum endosulfan residue levels were significantly
higher in the study population than in the control group even 10 months
after the last aerial spray."
Further, in 1991, the technical registrants amended labels to incorporate a 300-foot spray drift buffer for aerial applications between treated areas and water bodies. This setback was adopted in order to address concerns about contamination of water and risks to aquatic organisms. In 2000, the technical registrants amended technical product labels to remove all residential use patterns. Currently, there are 94 endosulfan products registered.
EHP is the journal
of the National Institute of Environmental Health Sciences, part of
the U.S. Department of Health and Human Services. More information is
available online at http://www.ehponline.org/.