Air Pollution Linked To Low IQ In Children

Jenny Decker RN's picture

In years past, there has been concern about lead, mercury, and other chemicals and how they affected children. The Environmental Protection Agency focused on these specific chemicals and pollutants, updating risk guidelines. However, the guidelines were only the cancer risk guidelines. It was concluded that these chemical were 10 times the potency for cancer in children than in adults. Unfortunately, these guidelines do little for any policy on how air pollution and food chain chemicals affect the immune system, the brain, the hormone system, kidneys, liver, lungs, thyroid, and other problems that may be targeted by dangerous chemicals. Air pollution and low IQ in children is definitely one of the many concerns that should be considered.

In a recent study by the Environmental Working Group (EWG) and Commonweal, over 200 chemicals and pollutants were found in umbilical cords of 10 babies that were born between the months of August 2004 and September 2004 in the United States. Pesticides, consumer product ingredients, and wastes from burning coal, gasoline, and garbage were found in the umbilical cord blood of these babies. Many of these were probably from air pollution that may lower IQ in children.

Other studies have shown that children in suburban areas are at increased exposure to air pollution. With this exposure, it was found that IQ was about 4 to 5 points lower than other children. However, it is important to understand how this really affects the IQ. Normally, IQ is about 100. So, if a child has an IQ of 96, they are well within normal limits. About half the population’s IQ is between 90 and 109. In addition to that, the studies were what researchers call ‘correlation studies’. This means that there is only a connection between air pollution and low IQ in children. However, this sets the stage for more in depth and rigorous studies.


To understand why children are more at risk for lower IQ’s from air pollution, it is important to understand how they grow and develop and subsequently, how any type of pollution can adversely affect them. Consider for a moment the huge amount of growth that occurs just a few weeks after conception. If this rate of growth continued throughout prenatal life, the baby would be born the size of millions of Earths. So, with this rate of growth, the baby is susceptible to a number of stressors. It is much more vulnerable to results such as birth defects and significant problems with many systems of the body.

In the study by the EWG and Commonweal, some of the chemical and pollutants found in cord blood were pesticides, stain and grease resistant coatings for food wrap, carpet, and furniture (such as Teflon, Scotchgard, and Stainmaster), fire retardants in TVs, computers, and furniture, polychlorinated biphenyls (PCBs) from electrical insulators, and waste byproducts from garbage incineration and plastic production wastes, car emissions and other fossil fuel combustion, and methylmercury from coal burning. Many of these chemicals and byproducts adversely pollute the air and may contribute to the lower IQ in children.

With these initial studies on air pollution and children, it will be critical in the future to determine which chemicals lower the IQ and what other factors may contribute and add to these problems we are now only beginning to understand.

Reference: EWG