Thursday, August 16, 2018

First biomarker evidence of DDT-autism link

Via dailykos.com and sciencedaily.com


First biomarker evidence of DDT-autism link

National birth cohort study finds DDT metabolites in the blood of pregnant women are associated with elevated odds of autism in offspring
Date:
August 16, 2018
Source:
Columbia University's Mailman School of Public Health
Summary:
A study of more than 1 million pregnancies in Finland reports that elevated levels of a metabolite of the banned insecticide DDT in the blood of pregnant women are linked to increased risk for autism in the offspring. The study is the first to connect an insecticide with risk for autism using maternal biomarkers of exposure.

Via nature.com

Brown's team found no correlation between the PCB by-product and autism. But when they measured DDT by-product levels in the blood samples, they found that mothers with high concentrations of this chemical — those in the top quartile — were 32% more likely than women with lower DDT levels to give birth to children who developed autism. The likelihood that a child with autism accompanied by intellectual disability was twice as high in mothers with elevated DDT levels compared to those with lower levels.
...
Brown cautions that although there seems to be a link between autism and DDT exposure, the overall risk of having a child with the disorder is low — even among women with high DDT levels. His group plans to look at other organic chemicals in the Finnish database to determine whether they might affect fetuses by interacting with DDT. 
Jonathan Chevrier, an epidemiologist at McGill University in Montreal, Canada, is interested in knowing whether DDT levels are linked to intellectual disability in children who do not have autism. He is currently following more than 700 children in South Africa — where DDT is still used — which could provide hints as to the mechanism by which the pesticide might affect the brain. It’s an important question, he says, given how much DDT persists in the environment, even in places that have banned its use. “At this point, essentially the entire planet is contaminated with DDT,” he says.