Thursday, April 28, 2011

The Impact of Prenatal Exposure to Pollutants: The China Initiative

Taiyaun City
The Columbia Center for Children’s Environmental Health (CCCEH) launched its first China study in 2001. The study was conducted in Tongliang, China, where a coal-fired power plant located in the center of town was the major source of ambient air pollution. In 2004, local officials shut down the power plant, creating a unique opportunity to study the effects of energy-related air pollution on children’s health before and after the plant’s closure.

Researchers specifically documented the impact of in utero exposure to polycyclic aromatic hydrocarbon (PAHs), a carcinogenic pollutant emitted from fossil fuel burning. The study tracked two cohorts of pregnant women and their children: the first was enrolled while the plant was still operational, and the second was enrolled after government authorities shut the facility down.

The study found that prenatal exposures to coal-related air pollutants adversely affected children’s health and neurodevelopment. Analyses showed that children born in 2002 when the power plant was still operating had higher levels of exposure to combustion-related PAH (measured by PAH-DNA adducts in cord blood) compared to the later cohort. Children with higher levels of prenatal exposure to PAHs had reduced head circumference at birth and a lower growth rate in childhood.

It was also shown that children who had higher levels of prenatal exposure to PAHs scored lower on the Gesell Scales of Child Development at age 2 and had more developmental delays than children who were less exposed in utero. Children born in 2005 by contrast, just a year after the plant was closed, had significantly lower levels of PAH-DNA adducts in cord blood, and did not show significant associations between PAHs and growth and developmental effects.

Tongliang power plant.
Building on this strong foundation in Tongliang, CCCEH launched a new serial prospective cohort study in Taiyuan and Changzhi, China. Taiyuan is the capital of the coal-rich Shanxi Province and is one of the most polluted areas of the country. This unfortunate distinction has been recognized by the Chinese government and the region is beginning to implement strong new policy measures to reduce air pollution over time.

Changzhi, also located in Shanxi Province, was selected for its lower pollution levels and thus serves as the concurrent control for the study. CCCEH’s goal is to document the direct benefits of these government policies in Taiyuan in terms of air quality, biomarkers of exposure in cord blood, and health and developmental outcomes in the children. These study findings, in conjunction with the findings from the Mothers and Newborn Studies in Tongliang, Krakow and New York City, have implications for future energy and public health policies in China and other coal-dependent nations.

Deliang Tang, MD, DrPH
Department of Environmental Health Sciences
Mailman School of Public Health

Other Investigators on the China Initiative: Frederica Perera, DrPH, and Julie Herbstman, PhD.

*Columbia University’s Mailman School of Public Health is pleased to announce a new practicum opportunity for MPH students at Fudan University’s School of Public Health (FUSPH) in Shanghai. FUSPH is offering a unique 3-6 month internship for students interested in international research. Two students will be selected to participate each year. The program is headed by Dr. Zhijun Zhou, Vice Dean of FUSPH.