Hyderabad: The reason for intellectual disability or autism is the presence of dichlorodiphenyltrichloroethane (DDT) in the food chain which is found to affect a section of pregnant woman despite being banned in several countries, according to a study published in the American Journal of Psychiatry.
European countries and the United States of America have banned DDT since 1970 but it continues to be used in India. Its use in agricultural farms is estimated to be 2,300 tonnes, according to the government report of 2017. DDT is used for disease vector control in agricultural farms.
The shift to organic farming or growing of vegetables with less use of pesticides is being propagated as it is found that insecticides and pesticides are the reason for the increasing incidence of cancers.
DDT is also one of the reasons for low birth weight of the baby, miscarriages and delay in the neurological development of the child.
Researchers have studied 750 children born with autism from 1987 to 2005 and used bio-markers for the first time where they have found levels of dichlorodiphenyl (DDE). DDE is a breakdown product of the pesticide DDT. The researchers have found that the levels in the mother were high due to which the transfer from the mother to the child took place.
With new and better diagnostic techniques, autism is now found in 1 in 59 children from the earlier ratio of 1 in 68 children. In India there are an estimated 1 million children with autistic disorders, according to neurologists.
Dr C.H. Mohan Rao, senior consultant neuro physician at Apollo Hospitals, explained, “Autism is due to multiple factors like genetic condition, environmental condition, age of the mother during pregnancy and other factors. Genetic conditions cause Down’s Syndrome, Fragile X Syndrome and Tuberous Sclerosis. Disintegrative disorder, pervasive development disorders and others are due to environmental and genetic factors.”
Experts state that there are several factors for the neurodevelopment of the child being affected and here the age of the mother also plays an important role. Gynaecologist Dr Radhika Reddy explained, “The quality of eggs deteriorate when a woman crosses 40 years of age. This is an established fact and these pregnancies have to be monitored to check for defects in the child. The environment and the food chain have a role to play but the age of the mother is also a major factor which can’t be undermined.”
