Use of DDT Might Be Linked to Low Sperm Counts, Other Harm to Male Reproductive System, Study Says

The use of the pesticide DDT to control the spread of malaria might be linked to low sperm counts and other harm to the male reproductive system, according to a study published recently in the Journal of Andrology, the Mercury/Independent Online reports. For the study, Tiaan de Jager and colleagues from the University of Pretoria's School of Health Systems and Public Health collected and analyzed semen samples from 311 men between ages 18 and 40 in the Thoyohandou/Vhembe area of South Africa's Limpopo province. The researchers found that 28% of the men had subnormal sperm counts, 99% had abnormal sperm morphology and 32% had subnormal sperm motility. The researchers also studied blood samples of men in Limpopo during a two-year period and found "very high levels" of DDT and its breakdown product, DDE, in the samples, according to the Mercury/Independent Online. The blood sampling analysis is still ongoing. The study also has raised concerns about male reproductive health problems in rural areas of the provinces of KwaZulu-Natal and Mpumalanga, the Mercury/Independent Online reports. The study also indicates that people whose residences have been sprayed with DDT might have high levels of exposure to the pesticide. DDT concentration levels in some of the men in the Limpopo study were among the highest recorded in medical literature, the Mercury/Independent Online reports. The researchers said that the high DDT levels in the Limpopo study "indicate that there is acute exposure to DDT, and the high DDE levels indicate chronic long-term exposure." According to the researchers, there is increasing evidence worldwide that DDT can be an endocrine-disrupting substance that alters the normal human hormone balance, decreases testosterone levels and possibly interferes with certain sexual organs. In addition, de Jager on Wednesday said that there now is sufficient evidence to alert the South African Department of Health about the health effects of DDT and to convince the department to consider adopting alternative strategies to control malaria. South Africa's National Research Foundation and Medical Research Council funded the study (Carnie, Mercury/Independent Online, 4/12).