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A scientific study reports that the air pollution that's so common to our cities and even suburbs could put unborn babies at risk for mental deficiencies. This ScienCentral News video has more.
Clear summer skies may cloud our thoughts of air pollution. But however clear the day might be, pollution from cars, trucks and the burning of fossil fuels still abounds. And it doesn't just affect those of us who breathe it. A new study suggests that those who can't breathe yet are also at risk.
"Children who had had more exposure in the womb to these combustion-related air pollutants scored significantly lower on the tests for mental development, and were more than twice, almost three times as likely to be developmentally delayed compared to the less exposed children," says environmental health scientist and molecular epidemiologist Frederica Perera.
Her research team tested the mental development of 183 New York City kids at ages one, two and three. Their mothers wore air monitors during the final month of pregnancy to measure their exposure to pollutants.
"The pollutants we're looking at are extremely widespread, really everywhere, not only in the urban areas but, in the suburban areas as well," she says. "We generate a lot of these pollutants locally, right here out on our streets and highways, we also have pollution from smoke stacks and power plants."
She also notes that children with these delays may not do as well in school later on. "We take that as a meaningful indicator of the longer-term risks."
Perera is Director of the Columbia Center for Children's Environmental Health at Columbia University's Mailman School for Public Health. Her research team has been working with the same group of non-smoking African-American and Dominican women, and their babies, since the women were about halfway through their pregnancies. The women were recruited from the neighborhoods surrounding Columbia University to participate in a broad, multi-year research project called, "The Mothers and Children Study in New York City." The ongoing study, which began in 1998, was designed to examine the health effects of exposure to indoor and outdoor air pollutants, pesticides, and allergens, with the hope of helping to prevent common childhood disease and developmental problems.
It's important to note that this study did not show biologically how these combustion-related pollutants, known as polycyclic aromatic hydrocarbons (PAHs), might cause these effects, but previous animal studies support the connection. And since mothers living in the same neighborhood were exposed to different levels of pollution, even neighbors are not necessarily at the same risk.
But Alan Arslan, an assistant professor of Obstetrics an Gynecology and Environmental Medicine at New York University's Medical Center says Perera's is a very important study, "It's one of the first study that looks at prenatal in utero exposure… It's cause for concern," he says. "I think the study needs to be replicated, it's a warning bell that needs to be conserved by future studies."
"Developmental problems are common," Perera says. "As many as 17 percent of U.S. children have a developmental disability. And childhood cancer, although a rare disease, the rates are far too high and affect 9,500 new children every year."
In an earlier study, Perera showed an association between higher levels of exposure to pollution in the womb and increased chromosomal changes in genetic material taken from the blood of the umbilical cord. "That's a potentially important finding with respect to cancer risk because other studies have linked to these chromosomal changes to increased risk of cancer in adults," Perera explains.
They have also found that exposure in the womb to pollutants may be linked with lower birth weight, and smaller head size.
"And that was of concern to us because we knew from other studies that reduced fetal growth of the type that we were seeing had been linked to more health problems and worse cognitive development," she explains. "In this study we have been able to follow the mothers and children from pregnancy all the way through delivery and infancy and on into childhood."
Perera says parents can help protect their children before and after birth by keeping their homes smoke-free, using non-toxic cleaning products and methods of pest control, and giving kids a good diet. They can also work to encourage policymakers to pay more attention to preventing and reducing air pollution. "Fortunately there are ways to curb and sharply reduce these pollutants, since they are emitted from the burning of fossil fuels. We can have much more efficient energy technologies," she says. However, "The very early months and years of development of children are exquisitely sensitive to certain environmental exposures and they do require protection and more vigilance."
At the end of the day, the researchers also reach out to the families of the children affected by pollution. They offer them advice about what they can do to protect their children, and refer the children to early intervention services, which can be very effective in helping the children to build their skills and overcome their developmental delays.