Shutting down coal and oil-fired power stations leads to healthier babies, according to new research.
Closing the polluting power plants lowers the rate of premature births in neighbouring communities as well as improving fertility.
US researchers compared preterm births and fertility before and after eight power stations in California closed between 2001 and 2011, including San Francisco’s Hunters Point plant in 2006.
Overall, the percentage of preterm births – babies born before 37 weeks of gestation – dropped from seven per cent during a year-long period before plant closure to 5.1 per cent for the year after shutdown.
The 20 to 25 per cent drop in premature birthrates was larger than expected, but consistent with other studies linking birth problems to air pollution around power plants, according to the findings published in the American Journal of Epidemiology.
Another paper, published in the journal Environmental Health, used similar data and found that fertility – the number of live births per 1,000 women – increased around coal and oil power plants after closure.
Lead author of the first study, postdoctoral fellow Dr Joan Casey, of University of California, Berkeley, said: “We were excited to do a good news story in environmental health.
“Most people look at air pollution and adverse health outcomes, but this is the flip side.
“We said, let’s look at what happens when we have this external shock that removes air pollution from a community and see if we can see any improvements in health.”
She said the findings could help policy makers more strategically plan the decommissioning of power plants as they build more renewable sources of energy, in order to have the biggest health impact.
Co-author Professor Rachel Morello-Frosch, also of University of California, Berkeley, said: “We believe that these papers have important implications for understanding the potential short-term community health benefits of climate and energy policy shifts and provide some very good news on that front.
“These studies indicate short-term beneficial impacts on preterm birth rates overall and particularly for women of colour.”
The researchers compared preterm birth rates in the first year following the closure date of each power station with the rate during the year starting two years before the plant’s retirement, so as to eliminate seasonal effects on preterm births.
Dividing the surrounding region into three concentric rings three miles wide, Dr Casey delved into state birth records to determine the rate of preterm births in each ring.
Those living in the closest ring, within three miles of the plant, saw the largest improvement: a drop from seven to 5.1 per cent.
But people living in the next nearest zone showed less improvement.
The researchers also considered the effects of winds on preterm birth rates, and though downwind areas seemed to exhibit greater improvements, the differences were not statistically significant.
As a control, they replicated their analysis around eight power stations that had not closed, and found no before-versus-after difference, which supported the results of their main analysis.
There did not appear to be any effect on births before 32 weeks, which Dr Casey said may reflect the fact that very early births are a result of problems, genetic or environmental, more serious than air pollution.
She added: “It would be good to look at this relationship in other states and see if we can apply a similar rationale to retirement of power plants in other places.”
Dr Pauline Mendola, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, said of the findings: “Perhaps it’s time for the health of our children to be the impetus behind reducing the common sources of ambient air pollution.
“Their lives depend on it.”