Flame Retardant, Pesticide Chemicals Linked with Autism

Children born to women exposed to high levels of a flame retardant and a banned pesticide chemical are at high risk of developing autism-like symptoms.

A new study, conducted by researchers at Simon Fraser University and colleagues, found that flame retardant PBDE-28 and pesticide Chlordane are linked to behavioural problems in children.

The pesticide Chlordane contains a chemical called trans-nonachlor. According to the researchers, chlordane was banned in the 1980s because it was found to be a carcinogenic. PBDE-28 has been linked to poor development of infants' thyroid hormones.

Autism can cause significant social, communication and behavioral challenges. Both genes and chemicals in the environmental raise autism risk.

"This type of study is critical to screening the myriad chemicals that pregnant women and children are exposed to, and to identifying the ones that elevate a child's risk of developing autism," Bruce Lanphear, an SFU health scientist involved in the study, said in a news release.

For the study, researchers analyzed blood and urine samples obtained from 175 pregnant women in the Cincinnati, Ohio area. Researchers found that on an average the women had some 44 suspected hormone-disrupting chemicals in the samples.

After five years the mothers were asked to rate their children's behavior. Higher scores on this questionnaire meant that the children had autism-like symptoms.

Most children scored between 30 and 90 on the test. Children who scored higher than 60 had poor social behavioural skills.

Researchers found that children, whose mothers were exposed to PBDE-28, had 2.5 point higher score on the test than those children born to other women.

Children of mothers exposed to the chemical chlordane scored 4.1 points more than other children in the study, researchers found.

A major limitation of the study is that researchers didn't account for genetics or presence of other contaminants that might have skewed the results of the study. The team also didn't look at chemical exposure levels post-birth.

Researchers have acknowledged that more investigation is required to establish a link between the chemicals and autism.

The study is published in the journal Environmental Health Perspectives.

April 2, is World Autism Day.