A recent study has found that the children of women exposed to elevated levels of DDE while they were pregnant had increased rates of pneumonia and bronchitis in their first year of life. This study is the largest of its kind, according to the researchers, and it is the first to demonstrate an important link between DDE exposure and lung infections within children.
DDE is a compound found in DDT, a once extensively used pesticide until it was banned in the US in 1973 after the scientific and medical communities expressed dire concern over its effect on wildlife populations, as well as the potential harm it posed to humans. The chemicals can be absorbed into the body through consumption of contaminated food or by breathing in contaminated dust.
"We found that the risk of infections and wheeze increased with increasing DDE exposure," Martine Vrijheid, associate professor at the Centre for Research in Environmental Epidemiology in Spain, told Reuters Health
Vrijheid and her fellow researchers obtained blood samples from a birth cohort of 1,455 mother-child pairs. They measured the levels of DDE, polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) in the mothers during pregnancy. When the children were between 12 and 14 months of age, the researchers requested parental reports on lower respiratory tract infections and wheezing.
They found that 35.4 % of the 1,342 children developed a lung infection within their first year; further, they connected higher levels of DDE in the mother’s blood during pregnancy with increases in risk for pulmonary distress in the children. No association was made between PCBs or HCB with wheeze and tract infections in the children.
Undetectable or very low levels of DDE would have resulted in only 30% of the children developing infections, said Vrijheid.
According to the Centers for Disease Control and Prevention
, exposure to significant levels of DDT can cause tremors, seizures, sweating, headaches and vomiting in human beings, but after exposure to the pesticide ceases, the symptoms vanish.
Today, DDT is still used in other parts of the world to kill malaria-carrying mosquitoes. The pesticide and its breakdown products are capable of enduring in an environment for an extended period time, possibly even hundreds of years.
The World Health Organization endorsed an alternative method in 2006 for killing mosquitoes with DDT involving lacing the interior of buildings with the pesticide to kill bugs that land on its walls and other surfaces.
While steps are constantly being taken to reduce DDT’s impact on wildlife and humanity, avoiding chemicals like DDT and DDE altogether is very difficult as they are stored in fat and found in higher concentrations at the top of the food chain, according to Vrijheid.
"One way of reducing exposure is by reducing the consumption of fatty foods and increasing the consumption of vegetables and fruits," Vrijheid told Reuters Health. "This does not mean we should stop eating meat, yogurts or certain types of fish, but just that we should have (a balanced) diet."
This study was published in the European Respiratory Journal