(Reuters Health) - - Where communities get their electricity may directly determine their citizens’ health and wellbeing, a new study suggests.

The research links the shut down of two nuclear power plants in the Tennessee Valley during the 1980s to decreased birth weights among babies in the area, and pins the blame on increased pollution from coal power plants.

“Clearly there was an effect of coal emissions driving pollution and - in turn - infant health,” said the study’s author Edson Severnini, of Carnegie Mellon University’s Heinz College in Pittsburgh.

Severnini writes in Nature Energy that nuclear accidents are often followed by backlash against the power source. Three Mile Island Unit 2 reactor near Harrisburg, Pennsylvania, partially melted down in March 1979.

Inspections following that incident led to long shutdowns of nuclear power plants around the U.S., including the Tennessee Valley Authority’s Browns Ferry and Sequoyah plants in 1985, he adds.

Coal-fired power plants picked up the slack in the areas that had been served by the two nuclear plants. For the new study, Severnini used several data sources to look at whether increases in air pollution from the coal power plants had negative effects on infant health.

He found air pollution measured by particles in the air increased from about 40 micrograms per cubic meter to about 50 micrograms in communities closest to one of the coal power plants that increased production to compensate for the idle nuclear plants.

Babies born between March 1985 and September 1986, after the nuclear plant shutdowns, were 0.30 pounds (134 grams) lighter at birth than those born between September 1983 and March 1985, before the shutdowns.

Severnini said the difference in birth weights between the two time periods is roughly the difference in birth weights between a baby born to a mother with a disadvantaged background who received supplemental nutrition during pregnancy and a baby born to a similar mother who didn’t get that help.

“If you compared these effects to the effect of supplementary nutrition to women with a disadvantaged background, the magnitude is comparable in different directions,” he said.

Frank Gilliland, of the Division of Occupational and Environmental Health at the University of Southern California’s Keck School of Medicine, expressed concern about the validity of the results because the magnitude of pollution’s effect on birth weight is larger than previously reported.

In addition, air pollution in the study was assessed using an outdated measure that includes all particles, including those too big to reach the respiratory tract, he said.

Nonetheless, there is an established body of literature that shows a link between increased air pollution and decreased birth weight, said Gilliland, who was not involved with the new study.

“The choices in terms of modes of energy production are important,” he said. “They have consequences.”

Severnini said there are a number of ways air pollution can affect a developing fetus, including by altering its mother’s inflammation levels, blood coagulation and blood pressure. The exact mechanisms are still under evaluation, however.

He told Reuters Health the new study shows it isn’t just the intended consequences of energy choices that matter. “The ultimate goal was to protect public health, but by not taking into account this response, public health was being affected in another way.” The unintended consequences matter, too, Severnini said.

Gilliland said there could be other unintended health consequences to look at including the entire population’s heart and respiratory health and the health impact of climate change.

“I think further research in this area is probably warranted to quantify the other risks associated with the trade off between air-polluting power generation and non-polluting power generation,” he said.

SOURCE: go.nature.com/2nBnVFN Nature Energy, online April 3, 2017.