A new study published Monday in Environmental Health Perspectives revives fears about the pesticide environmentalists everywhere love to hate: DDT. Researchers examined 129 women who were exposed to the pesticide as children and found that the women had a whopping 400% increase in breast cancer risk.
This isn’t the first time the link between breast cancer and DDT has been examined, but previous studies were either inconclusive, questionable or found no link. The difference this time, according to the researchers, is that these baby boomer women were exposed to the pesticide in the 1950s and 60s, before they were 14 years old. The age of exposure has a great deal to do with breast cancer risk, apparently.
I have some doubts about the study because of its size, but even if it is confirmed by other research, it’s important to emphasize that the study was looking at women who were exposed to the pesticide as it was used in the 1940s and 50s, when it was sprayed widely — one might say recklessly — for agricultural purposes. That’s now banned in most parts of the world.
Where it is used, DDT is sprayed indoors, in very small quantities, for malaria control. And in fact, it’s the most powerful tool available against the mosquitoes that spread malaria. That’s why, despite its sketchy reputation, the WHO and others decided to support its use in Africa, as I reported last summer. Studies like this are often misused and misinterpreted. But the consequences of dismissing DDT’s benefits are far too serious to contemplate.
On a completely unrelated note, yesterday was my last day as senior news editor at Nature Medicine. As of next week, I’m joining the Simons Foundation, where I’ll be helping to create an online community for autism researchers. It’s been a pleasure contributing to this blog, however infrequently I’ve done it lately. I hope you’ve enjoyed reading it — and will join me on my personal blog, which I hope to have up and running sometime soon.