By Mary Elizabeth Dallas
TUESDAY, May 22, 2018 (HealthDay News) -- Closing coal and oil plants may lead to fewer premature births and improved fertility in neighboring communities, according to two new studies.
Scientists at the University of California, Berkeley found that preterm deliveries dropped 20 percent to 25 percent in California after eight power plants closed down between 2001 and 2011.
"We were excited to do a good news story in environmental health," said study lead author Joan Casey, a postdoctoral fellow.
"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," Casey said in a university news release.
Researchers compared premature births and fertility rates in women two years before and one year after the closures. The facilities included San Francisco's Hunters Point Power Plant, which was retired in 2006. The women's age, socioeconomic status, education level and race were also taken into account.
Next, the researchers divided the neighboring areas into three rings that measured 3 miles wide. Then they analyzed state birth records to identify trends in premature births within each ring.
The most significant improvement occurred in the ring closest to the plant -- within 3 miles, the researchers said.
Overall, the team found that preterm births -- before 37 weeks of pregnancy -- dropped from 7 percent to about 5 percent.
Among black and Asian women, premature deliveries fell more significantly -- from about 14 percent to a just over 11 percent, the study showed.
Casey said the 20 to 25 percent drop in preterm birth rates was larger than expected, but in keeping with other research tying birth problems to air pollution around power plants.
"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," Casey said.
The researchers compared their findings to an analysis of eight power plants that were still operational and found preterm rates remained the same. They said this supports their conclusion.
The findings appear May 22 in the American Journal of Epidemiology.
A separate study was published May 2 in Environmental Health. For that work, UC Berkeley researchers examined similar data and found that fertility improved around coal and oil power plants once they closed.
But as in the first study, only an association was seen between plant closings and birth outcomes.
"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," said study co-author and professor Rachel Morello-Frosch.
"These studies indicate short-term beneficial impacts on preterm birth rates overall and particularly for women of color," Morello-Frosch added.