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Everyday exposure to a ubiquitous compound that makes plastics flexible and stabilizes air fresheners may result in lasting damage to children’s respiratory systems. The first study to explore the relationship between phthalates during pregnancy and future childhood asthma reveals a strong link between the two, but cannot conclusively say that asthma is a result of the exposure.
Phthalates are known to impede the endocrine system, the regulatory mechanism that dictates hormonal distribution in the body. The chemicals’ disruptive prowess have been linked to health problems including birth defects, cancers and diabetes. Yet until now there has been no data to suggest they were also harming children’s respiratory systems.
This new study of 300 inner-city women and their children found that women who were exposed to elevated levels of two common phthalates—butylbenzl phthalate and di-n-butyl phthalate—during pregnancy were more likely to have children who developed asthma. The researchers discovered this by scouring metabolites in the women’s urine and then tracking their children via questionnaires and physicians’ diagnoses.
Children of women who were exposed to higher levels of phthalate during pregnancy (in some cases a dozen times higher) were some 70 percent likelier to develop asthma by age 11 compared with the offspring of mom’s with lower exposure. But with both exposure groups the levels were still not that high—the concentration of the phthalates among all the women were generally comparable with those of a representative sample of the U.S. population taken over roughly the same time period. If the asthma findings are replicated by other studies, this new link could have serious implications for the general population.
In this study all the mothers were from low-income areas and the women self-identified as African-American or Dominican. Typically people who live in impoverished urban neighborhoods are more prone to have higher asthma rates due to a variety of factors including elevated exposure to harmful pollutants like diesel exhaust. That makes the new findings even more striking because it would typically be harder to pick up increased rates of asthma compared with an already high number of background cases. The women and their children were enrolled in a longitudinal study run by the Columbia Center for Children’s Environmental Health.
This research, published in the journal Environmental Health Perspectives, controlled for many factors that could account for the findings like maternal asthma and smoking status. The phthalate levels we see here are typical in the U.S. population and not “whoopingly high,” which makes this an important finding, says Linda Birnbaum, director of the National Institute of Environmental Health Sciences. “The population distribution here isn’t that different than [earlier work looking at such exposures in the general population].” The study is also of interest because it indicates that not all phthalate exposures have the same effects, she says. The work looked at four types of phthalate but only two of them were associated with elevated asthma risk.
Limiting exposure to worrisome phthalates is doable, says lead author Robin Whyatt, a professor in the Department of Environmental Health Sciences at Columbia University. She tells people worried about these exposures to never microwave plastic, avoid plastics with “3” or “7” on the bottom (because they can be made with phthalates and bisphenol A) and to store food in glass jars instead of plastic. Also, avoid scented products whenever possible, such as room fresheners and scented detergents.