Since the publication of Rachel Carson’s Silent Spring in 1962, use of DDT in the western world has been all but outlawed. Not so for our southern counterparts. DDT continues to be used to combat malaria in much of the developing world. Indoor Residual Spraying – the practice of praying DDT inside people’s homes – is still endorsed by the WHO and USAID, and classified as only “moderately hazardous.”
A recent report in Environmental Health Perspectives suggests that DDT use to ward of misquotes may be, well, misguided. Apparently indoor spraying leads to far higher levels of DDT in the blood, which in turn leads to diabetes, cancer, infertility and impaired brain development. Seems obvious, but when weighed against the impact of malaria, the number one killer in much of the world, the issue becomes more complex. SEED magazine has an interesting interview with the authors of the report which tries to explain why the WHO endorsed the practice of spraying DDT to begin with.
Several UN agencies, including the WHO, have set a deadline of 2020 to stop use of the pesticide and replace the practice with more suitible malaria-fighting solutions. Here are some of the proposed solutions. I am particularly fond of #2: Engineer a Vaccine. Which is good news, because phase three trials of RTS,S commenced in Tanzania in May. This is the largest clinical trial of its kind in history, with initial results indicating the drug reduces the risk of malaria by 53 percent. Good news, and about time.
