Therapist Unlimited Blog

Pregnant women around the world should avoid exposure to environmental pollutants known as polycyclic aromatic hydrocarbons (PAHs) since it can adversely affect a child’s intelligence quotient or IQ.
Based on the study conducted by the Columbia Center for Children’s Environmental Health (CCCEH) at the Mailman School of Public Health it was learned that PAHs are chemicals released into the air from the burning of coal, diesel, oil and gas, or other organic substances such as tobacco.
It is said that in urban areas motor vehicles are a major source of PAHs.
According to the study, funded by the National Institute of Environmental Health Sciences (NIEHS), a component of the National Institutes of Health, the U.S. Environmental Protection Agency and several private foundations, children exposed to high levels of PAHs in New York City had full scale and verbal IQ scores that were 4.31 and 4.67 points lower, respectively than those of less exposed children.
Researchers reveal high PAH levels were defined as above the median of 2.26 nanograms per cubic meter (ng/m3).
Frederica Perera, DrPH, professor of Environmental Health Sciences and director of the CCCEH at Columbia University Mailman School of Public Health and study lead author explained their findings are of concern because these decreases in IQ could be educationally meaningful in terms of school performance.
Perera added the good news is that they have seen a decline in air pollution exposure in our cohort since 1998, testifying to the importance of policies to reduce traffic congestion and other sources of fossil fuel combustion byproducts.
The study included children who were born to non-smoking Black and Dominican American women age 18 to 35 who resided in Washington Heights, Harlem or the South Bronx in New York.
The children were followed from in utero to 5 years of age.

Pregnant women around the world should avoid exposure to urban air pollutants to protect the IQ of their children.

The mothers wore personal air monitors during pregnancy to measure exposure to PAHs and they responded to questionnaires.
At 5 years of age, 249 children were given an intelligence test known as the Wechsler Preschool and Primary Scale of the Intelligence, which provides verbal, performance and full-scale IQ scores.
The researchers developed models to calculate the associations between prenatal PAH exposure and IQ.
The researchers added other factors such as second-hand smoke exposure, lead, mother’s education and the quality of the home caretaking environment could also affect the IQ of the baby.
The study has shown that participants exposed to air pollution levels below the average were designated as having "low exposure," while those exposed to pollution levels above the average were identified as "high exposure."
A total of 140 children were classified as having high PAH exposure.
Furthermore, Perera said the decrease in full-scale IQ score among the more exposed children is similar to that seen with low-level lead exposure.
Perera added this finding is of concern because IQ is an important predictor of future academic performance, and PAHs are widespread in urban environments and throughout the world.
She said fortunately, airborne PAH concentrations can be reduced through currently available controls, alternative energy sources and policy interventions.