Junfeng “Jim” Zhang, professor of global and environmental health at Duke Kunshan, has received a $2 million grant to lead a four-year study in Shanghai on the effects of early-life and prenatal exposure to air pollution on birth weight and growth.
Birth weight and growth are two important predictors of childhood obesity, which is known to increase the risk of chronic diseases later in life.
Many factors that influence obesity, such as genetics and lack of exercise, are well documented, but scientists are only now beginning to explore the role that exposure to air pollution may also play during infancy, in the womb or even before conception.
“Despite the fact that 92 percent of the world population today lives in places where poor air quality exceeds healthy limits, no published studies have tested the possible critical time periods, including before conception, when air pollution may impact birth weight and child growth,” Zhang said.
Zhang and a team of researchers from Duke University, the University of Southern California, Fudan University Children’s Hospital and the Chinese Research Academy of Environmental Science will review data from the medical checkups for 20,000 newborns in Shanghai over the first two years of their lives.
The team will then model where and when the children were exposed to air pollution and test whether factors such as family wealth, a mother’s diet during pregnancy and parents’ smoking habits affect weight outcomes for the children.
“This could provide the first evidence supporting the idea that parental exposure to air pollution during critical time windows, including before conception and during pregnancy, can be a risk factor for low birth weight and excessive growth in childhood,” Zhang said. “That information would be critical for promoting strategies to reduce children’s exposure to air pollution.”
The team has received the $2 million grant from the United States National Institute of Environmental Health Sciences.
Zhang, who also holds faculty appointments at Duke University’s Nicholas School of the Environment and the Duke Global Health Institute, has built a large body of work examining links between air pollution and human health, including a widely cited study conducted during the 2008 Beijing Olympics, during which the Chinese government undertook massive pollution-reduction efforts.
That study found that babies born to mothers whose late-term pregnancy coincided with the Games were a healthier weight than those born before or after the Games, when air pollution levels were much higher.