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. China is the most populous nations in the world and, like many rapidly developing countries, has relied heavily on coal burning for low-cost energy production. The incomplete burning of fossil fuels–coal and other organic substances—releases into the air a group of chemicals called polycyclic aromatic hydrocarbons (PAH), which are the main exposure of our study.
The Center launched its first study in 2001 in Tongliang, a city 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 PAH 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.
- Decreased exposure to air pollution from the coal-fired plant in utero was linked with improved childhood developmental scores and higher levels of brain-derived neurotrophic factor (BDNF), a key protein critical for early brain development
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 Studies in Taiyuan
In 2009, the Center launched a multi-level research program to track the benefits of broad government intervention in Taiyuan, the capital of the coal-rich Shanxi Province and one of the most polluted areas of the country.
In August 2014, we published a manuscript in Environment International describing policies enacted in Taiyuan over ten years (2000-2009), along with trends in environmental monitoring data, and community-level health outcomes and estimates of the substantial cost savings achieved from the reduction of air-pollution-related morbidity and mortality. The manuscript reviews policies in Taiyuan that removed or shut down a number of major sources such as power plants, encouraged new and greener technology, set initiatives and standards for industrial pollution clean-up, and held local government and leaders responsible for reducing pollution in their jurisdictions.
This led to reductions in air pollution and reductions in hospital admission rates, chronic bronchitis, and premature deaths from 2000-2009. The estimated cost savings as a result of lowered disease burden are 3.8 billion Yuan (or 618 million USD).
Our findings were reported in Shanxi daily, an official local newspaper and the most circulated paper in the Shanxi Province.
In November 2009, the Center began enrolling new serial prospective cohorts of pregnant women and their babies in Taiyuan and Changzhi, China. The latter is also located in the Shanxi Province but with markedly lower pollution levels. Our goal was to document the direct benefits of government policies enacted in Taiyuan on air quality, with the hope that such findings will encourage the adoption of pollution reduction efforts throughout the region.
A total of 1,260 mother-child pairs have been enrolled at three different time points, in 2009, 2011, and 2013. By recruiting successive cohorts during this time of rapid policy change, we are able to assess the effectiveness of those policy changes and estimate the health and neurodevelopmental benefits to the children, all of whom were screened and have completed consent forms approved by our partnering university’s Institutional Review Board (IRB).
Conference on translation of science to policy
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. In August 12-15, 2013, the Center co-hosted the Shanxi International Forum on Environment and Health. It was a landmark conference that brought together over 200 researchers and policymakers from different disciplines in China for the first time and was widely covered by the media.