The Mothers & Newborns Studies in China seek to determine the health benefits to newborns of reducing in utero exposure to toxic air pollutants generated by coal burning. Like many rapidly developing countries, China relies heavily on coal for low-cost energy. The incomplete burning of fossil fuels–coal and other organic substances—releases into the air a group of chemicals called polycyclic aromatic hydrocarbons (PAHs), which are the main exposure of our study.
The Center launched its first study in 2001 in Tongliang, a town where a centrally located coal-fired power plant was the major source of air pollution. In 2004, local officials shut down the plant, creating an ideal natural experiment in which the effects of energy-related air pollution on children’s health could be studied before and after the plant’s closure. The study tracked three distinct cohorts of pregnant women and their children: one that was enrolled while the plant was still operating, and two that were enrolled after local authorities shut the facility down.
Data collection for the Tongliang study has ended, and we are now focusing on analyzing the extensive body of data and biospecimens that we have collected.
Some key findings from this study:
Growth & Development
- Children with higher levels of prenatal exposure to PAHs had reduced head circumference at birth and a lower growth rate. The longer the duration of prenatal exposure—i.e., the number of months a pregnant woman lived near the operating plant—the more severe the reduction in children’s birth weight and height.
- Follow-up of the children through age five indicated that prenatal exposure to PAH and secondhand smoke impacted their IQs.
Cancer Risk & Genetic Susceptibility
- Our analyses showed that children born in 2002, when the power plant was still operating, had higher levels of exposure to combustion-related PAHs (measured by PAH-DNA adducts) than the later cohort and presented with impaired growth and cognitive development. In addition, PAH-DNA adducts have been linked to increased cancer risk in previous studies.
- By contrast, children born in 2005, just one year after the plant was closed, had significantly lower levels of PAH-DNA adducts in cord blood, and did not show these significant associations between PAH and growth and developmental effects. They also had improved developmental outcomes compared to the children who were in utero when the power plant was operating.
New Study in Taiyuan
In November 2009, two cohorts in two different cities within the same province were recruited for a new serial prospective cohort study. One city is located in the capital of a coal-rich province, known as one of the most polluted areas of China. 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, which the Center has been able document back to 2003. The second location was selected in the same province, but for its lower pollution levels and thus will effectively serve as the concurrent control. Our long-term goal is to document the benefits of new government policies to improve air quality, with the hope that such findings will encourage the adoption of pollution reduction efforts throughout the region.
By the end of April 2010 investigators had recruited four hundred mother-child pairs in both locations were completed by the end of April 2010, all of whom were screened and have completed consent forms approved by our partnering university’s Institutional Review Board (IRB).
Since 2001 we have continued to strengthen our partnerships with Chinese academic institutions and government entities including the region’s medical universities and center for disease control. For more detailed information on our newest studies in China, please click here.