Michael Casey
BANGKOK,
Thailand -- Children born
after the closure of a coal-burning plant in China
had 60 percent fewer developmental problems, a study released Monday suggests,
giving ammunition to those who argue the country should embrace cleaner sources
of energy.
The
study in the peer-reviewed Environmental Health Perspectives journal found that
after the coal plant was shut in the midwestern city of Tongliang, pregnant mothers
living in the area had far less exposure to pollutants and their children showed
significantly fewer delays in developing motor skills such as muscle
coordination by the age of 2.
"This study provides
direct evidence that the Chinese government's action to shut down a polluting
power plant had measurable benefits on the development of children," said
Frederica Perera, lead author of the
study and the director of the Columbia Center for Children's Environmental
Health in New York.
"These findings have
major implications for environmental health and energy policy in China
and elsewhere," she said.
The
study tested the development of two groups of about 100 children, one group born
before the Tongliang coal plant's closure in 2004 and the other born after it
was shut.
Barbara Finamore,
director of the Natural Resources Defense Council's China program whose group
helped researchers identify a site, said she was hopeful the findings would
persuade authorities to weigh the affordability of coal against the health
costs.
"Coal is much cheaper
than the alternatives. But when you factor in the cost of coal to children's
health, it changes the equation," Finamore said. "With the one-child policy,
children are one of China's most precious resources. They
cannot afford to be raising a new generation of children with serious
developmental difficulties."
China introduced rules in the late 1970s that limit many couples to only one
child.
But
Peter D. Sly, who heads the World Health Organization's Collaborating Center for Research on Children's Environmental Health
and is based in Australia, was more
cautious.
He
said it was an "interesting study" that shows how reducing exposure to
pollutants during gestation can improve health outcomes for children, especially
brain development. But he said the results do not have implications for "modern,
coal-fired power stations" in China.
The
Tongliang coal plant did not have pollution control equipment to limit the
emission of toxins that typically include carbon dioxide, sulfur dioxide,
nitrogen oxide and particulate matter.
"My
personal opinion is that modern power stations may be better, but we don't know
how much better," said Sly, who was not part of the study. "These data are not
strong enough to call for closing all coal-fired power stations but do suggest
the need for studies to examine the potential health effects of modern,
so-called, clean power stations."
China relies on coal for three-quarters of its electricity and has been slow
to switch to cleaner options such as wind, solar and
hydropower.
While it has fueled the country's economic boom, the
burning of coal has caused widespread air pollution in China,
contributed to worsening acid rain and helped make the country the world's top
emitter of carbon dioxide and other heat-trapping gases blamed for global
warming.
The
study found that mothers living near the coal-fired plant breathed in polycyclic
aromatic hydrocarbons, which are produced when coal is burned and were passed
onto their babies through the mother's placenta. Researchers tested the levels
of polycyclic aromatic hydrocarbons in the fetal umbilical cord blood of the
children in the two groups.
Researchers found the group that was born after the
power plant closed had 40 percent lower levels of the contaminant in the cord
blood and a 60 percent reduction in the frequency of "delayed motor
development."
Development delays typically reflect that a child is not
meeting certain benchmarks for his age, for example a 2-year-old who is not yet
climbing stairs well or grasping objects securely, researchers
said.
All
the women in the study were nonsmokers and exposure to secondhand smoke and lead
was carefully measured and recorded to ensure it did not affect the findings,
the researchers said.
"The government action
of shutting down a polluting plant allowed us to do something we couldn't do
before," said Perera, who collaborated with Columbia colleague Deliang Tang, Tin-yu Li of the
Children's Hospital of Chongqing Medical
University as well as other Chinese
scientists.
"In the past, almost
all research has evaluated the adverse effects of pollution," she said. "This in
a very real sense is a good news story."
The China research builds on ongoing work conducted
by Perera and her team which found reduced fetal growth in babies born to
mothers from coal-burning regions of Poland who were exposed to PAH. A
separate study the group did in New York City also found that mothers exposed to
more of the contaminant were likely to have children who scored lower on mental
development tests.
