Environmental Toxins and the Brain
All sorts of environmental toxins–lead, mercury, pesticides, for example–are known to affect the developing brain. A specific link to autism, however, remains elusive. At the Mailman School of Public Health at Columbia, Frederica Perera has been conducting a longterm study that is following several hundred inner-city children from before birth through age 11, looking at the effects of various environmental exposures on their development, growth and behavior.
In the past, Perera has linked exposure to the pesticide Dursban (chlorpyrifos) to low birth weight, developmental delays and deficits in attention and memory. Her latest study looks at another environmental toxin–substances called polycyclic aromatic hydrocarbons (PAHs), which are found in car and truck exhaust, factory emissions, cigarette smoke and basically any fumes resulting from the incomplete combustion of fossil fuels.
Perera’s studies of PAHs have linked high prenatal exposures (greater than 2.26 nanograms per cubic meter) to low birth weight, developmental delays, motor problems and now, in her latest study, lower IQ at age 5. In the study published in the current issue of Pediatrics, Perara found that kids with the higher exposure had a mean IQ of 96.5 compared with a mean score of 101.6 for kids in the low-exposure group. “A difference in four points could be educationally meaningful in terms of school success,” Perera told me in an interview.
Read more in my article for Time.com.