Scientists have found that women in African villages sprayed with DDT to reduce malaria gave birth to 33 percent more baby boys with urogenital birth defects (UGBDs) than women in unsprayed villages. Even worse, the women who stayed at home in the sprayed villages (rather than traveling to study or work) had 41 percent more baby boys with UGBDs. The defects, reported in the British Journal of Urology International, included missing testicles and/or problems with their urethra or penis.
The researchers studied more than 3,000 boys born to women from the Limpopo Province, where DDT spraying was carried out in high-risk areas between 1995 and 2003 to control malaria. The study compared boys born to women in 109 villages that were sprayed, with those born to women from 97 villages that were not.
Other factors were taken into account to rule out alternative causes of the birth defects. These included smoking and drinking, the mother's age, how long she had lived in her village and her race. These all proved statistically insignificant.
The results showed that 357 of the boys included in the study (just under 11 per cent) had UGBDs and the incidence of UGBDs was significantly higher if the mother came from a sprayed village.
"If women are exposed to DDT, either through their diet or through the environment they live in, this can cause the chemical to build up in their body," explained the study's lead author Professor Riana Bornman, from the University of Pretoria. "DDT can cross the placenta and be present in breast milk and studies have shown that the residual concentration in the baby's umbilical cord are very similar to those in maternal blood."
"The present findings strongly suggest that indoor residual spraying with DDT is associated with UGBDs in newborn boys," she added. "Although most countries have now banned the use of DDT, certain endemic malarial areas still use indoor residual spraying with DDT to decrease the incidence and spread of the disease, which is caused by mosquitoes."
Incredibly, it has been estimated that if DDT exposure were to cease completely, it would still take 10 to 20 years for an individual who had been exposed to the chemical to be clear of it. Education is the way forward according to the researchers. "Educating people living in the DDT-sprayed communities about ways of protecting themselves from undue DDT exposure needs to be carried out as a matter of extreme urgency. There must be long-term monitoring of possible environmental and human health impacts, particularly in those areas where DDT will be introduced as part of the fight against malaria," Professor Bornman concluded.
Related:
New Evidence Linking Pollutants To Penile Deformities
Call For Investigation Into Endocrine Disruptors
Dioxin Exposure Causing Vets Reproductive Troubles?
Source: British Journal of Urology International
