New Studies Link Pollution to Birth Defects
For Bloomberg Businessweek, Christina Larson writes that several recent studies have firmed up the link between pollution and birth defects in China and beyond:
Tong Zhu, now a Princeton Global Scholar, together with research partners at Peking University Health Science Center and the University of Texas at Austin, recently published results of a 10-year investigation of severe birth defects in one of China’s most polluted regions: coal-rich and coal-darkened Shanxi province. Specifically, the team was investigating the alarming frequency of congenital neural tube defects, in which portions of an infant’s brain, skull, or spine are missing or do not connect properly. Most babies born with this condition live only a few weeks.
In the U.S., for every 10,000 live births, there are 7.5 infants with neural tube defects. In Shanxi province, that number is 18 times higher: 140 infants. “We wanted to understand what’s really behind the problem,” says Tong, who previously worked at Peking University in Beijing. “We wanted to find out what chemicals caused this.”
Over a 10-year period, the researchers gathered placentas from 80 stillborn or newborn infants in Shanxi with the disorder. Based on their analysis, they confirmed that those infants had been exposed in utero to significant levels of pesticides, industrial solvents, and especially polycyclic aromatic hydrocarbons (PAHs), which are released into the air when fossil fuels are burned. In Shanxi, abundant coal is used for power plants as well as for home cooking and heating. “We found higher concentrations [of the chemicals] in the placentas of infants with the birth defects” than in other infants, explains Tong, who says there is a “clear association” between the environment the mother is exposed to and birth outcomes. Their findings (pdf)appeared in the Aug. 2, 2011, issue of the Proceedings of the National Academy of Sciences.