New China study reveals a link between air pollution and brain development in babies


By Katherine Martinko, published in Living Heath, March 24, 2014 (see

CC BY 2.0 Kevin Spooley

Developing fetuses are extremely vulnerable to the harmful effects of environmental pollution. As the cells of major organs develop during the first trimester, genetic mutations can occur that are impossible to reverse.

A new study conducted by Columbia University and Chongqing Medical University shows a clear connection between children conceived and raised near a Chinese coal-fired power plant and reduced neurological development when assessed at age two.

The power plant was located in Tongliang, near Chongqing City, with a population of 800,000. According to Bloomberg, the plant spewed out 2000 micrograms of particles per cubic metre of air, including particulate matter, carbon dioxide, sulfur dioxide, and heavy metals. This number was eight times the amount allowed by U.S. emissions standards.

When researchers heard that the plant would shut down in May 2004, they recruited two cohorts for study: one group of 150 non-smoking mothers in 2002, and a second group of mothers and children in 2005. Umbilical cord blood and maternal blood samples were taken upon birth, and the children’s neurological development was assessed at age two.

Researchers found that the children born before the plant’s shutdown had poorer learning and memory skills. They also had lower levels of a protein required for brain development in the cord blood samples. Parents reported their children’s illnesses, headaches, and lethargy. Lead author of the report, Deliang Tang from Columbia University, said

“I wasn’t anticipating such a clear difference when we compared the first and second cohorts, and this shows how much of an impact effective policies can have on local populations.”

That fetuses are bombarded with toxins in utero isn’t a new story, but that doesn’t make it any less alarming. Toxin Toxout tells of a 2009 study conducted by the Environmental Working Group in the U.S. that found 232 toxic chemicals in the umbilical cord blood of 10 babies. In Canada, the Environmental Defence released a report in 2013 that tested the umbilical cord blood of three newborns for the presence of 310 different synthetic chemicals. In the end, 137 were detected, including fire retardants, DDT, and PCBs.

It is horrifying to think of babies being born pre-polluted. It makes sense that the presence of so many toxins would negatively impact development, just as the Chinese study demonstrates. Deliang Tang is right that we need more and better policies to inhibit the use of these toxins, which could go a long ways toward reducing fetal and childhood exposure. Hopefully the results of this study will encourage the Chinese government to pursue clean energy alternatives.