‘Smog smothers growth of unborn babies’

BEIJING — China’s toxic smog is affecting foetal health, two new studies show, adding to pressure on the government to address the harmful levels of pollution that are becoming an increasing political liability.

A study of women who were pregnant during the 2008 Beijing Olympic Games, when the city reduced car traffic and halted many industrial plants in surrounding provinces, showed that their babies had significantly higher birth weights than those born the year before or after.

Research is slowly highlighting the health effects of China’s headlong rush to industrialise. Public dissatisfaction with persistent smog is growing, especially among wealthier residents in the capital.

Provincial cities routinely fail to meet China’s own standards for air quality.

China’s air pollution action plan, issued in 2013, calls for caps on emissions in prosperous and densely populated eastern cities, including Beijing, while moving many polluting industries to poorer areas in the hinterland.

Top-down measures to ensure clear days during high-profile international events, such as the 2008 Olympic Games or the Asia-Pacific Economic Cooperation (APEC) meeting late last year, highlight what can be achieved when strict pollution controls are enforced.

President Xi Jinping vowed at the meeting that “APEC-blue” skies should become routine, though popular sayings compared APEC blue with a fleeting love affair.

A study led by Dr David Rich at the University of Rochester Medical Center, along with scientists at Capital Medical University in Beijing, showed that mothers in their third trimester living in Beijing during the Olympic Games delivered bigger babies. Women in their first trimester showed little effect. The study followed 83,672 women.

On average, babies born soon after the Olympics were 23g heavier than those born in 2007 or 2009, the study found. The authors suggested that air pollution might impair the functioning of the placenta.

The “epidemiological revolution” of the past 20 years, with more refined statistical and health tracking methods, “has allowed public health effects to be measured as they couldn’t before”, said Dr Aaron Cohen of the Health Effects Institute in Boston. “It allows us to show in a definitive way, beyond a reasonable doubt, the longer-term effects.”

His institute is funding a study, led by Dr Zhengmin Qian of the Saint Louis University School of Public Health, that analyses 95,911 babies born between 2011 and 2013 in Wuhan, an industrial city located on the Yangtze River in central China. That study, which is still under review, found that higher levels of particulate matter in the air corresponded with more preterm deliveries.

The Wuhan study also showed differing effects of various pollutants on health. While higher levels of ozone and carbon monoxide contributed to earlier births, higher levels of sulphur dioxide and nitrogen dioxide did not. THE FINANCIAL TIMES