Expectant mothers should not be exposed to a particular pesticide
Researchers have now found that exposure to a notorious pesticide during pregnancy increases the child's risk of developing autism.
Columbia University researchers found in their current study that exposure to dichlorodiphenyltrichloroethane (DDT) pesticide during pregnancy may increase the likelihood of the child developing autism. The doctors published the results of their study in the English-language journal "American Journal of Psychiatry".
DDT is banned in most parts of the world
Exposure to the notorious pesticide dichlorodiphenyltrichloroethane (DDT) during pregnancy could increase the risk of a child suffering from autism. The pesticide became famous in the 1960s and has been banned in most parts of the world since then. However, some countries still use the pesticide.
Researchers analyze data from prenatal study on autism
A research team led by Columbia University used Finnish mother data for a prenatal study of autism. They identified 778 children who were born between 1987 and 2005 and who were diagnosed with autism. They compared the maternal blood samples that were taken during pregnancy from these children. Another 778 children and their mothers served as a control group. The blood samples were examined for the pesticide DDT as well as for its metabolites (p, p’-dichlorodiphenyl dichloroethylene; p, p’-DDE). These arise when DDT is broken down in our body. In addition, the research team measured the concentrations of another group of potentially toxic pollutants called polychlorinated biphenyls (PCBs).
How did PCB affect?
There was no evidence of a relationship between autism and PCB. However, the researchers found a significantly increased risk of diagnosing autism in the child if the mother had a serum DDE level that was in the top 25 percent. The child also suffered from intellectual disability along with autism in the lowest 75 percent of DDE scores twice as often.
What is DDT?
DDT is a common synthetic pesticide that was developed in the 1940s to destroy mosquitoes on a large scale. It was so effective that it was used practically everywhere, from harvesting to household use. The pesticide is very effective in combating the spread of malaria, the experts explain. While we do not worry much about the pest responsible for the spread of malaria in the wealthy western nations, malaria is still one of the greatest threats to humanity.
Many countries use DDT against malaria
The World Health Organization (WHO) only provides for an exception to indoor DDT use in regions with a significant malaria threat. However, many African countries continue to inject the malaria pesticide regularly. This further fuels the controversy. The chemical itself is only listed as moderately toxic, which means that humans have to experience quite a large exposure to die from its effects, the scientists explain. However, signs of subtle but serious health effects have increased over the decades. The researchers are now stressing whether autism should be included in the list of side effects.
What does the autism spectrum disorder do?
The study itself cannot clarify how DDT could affect brain development. The metabolite of DDT has also not been proven to cause autism, especially given the complex nature of the disorder, the study's authors say. This is characterized by difficulties in sensory processing, communication and socialization and seems to involve various neurological pathways and brain functions. Today, the condition is referred to as autism spectrum disorder to take into account the wide range of severity levels and manifestations of its key properties. Genetics undoubtedly play an important role in development, but environmental influences cannot be ruled out, the doctors say. It is difficult to determine the variety of causes behind this complex complaint, and as so often, further research is urgently needed, the researchers conclude. (as)