The author, Edson Severnini, took advantage of a natural experiment to use strict econometric methods to disentangle confounding variables.

Following the 1979 Three Mile Island accident, the Tennessee Valley Authority, a federal electric utility, temporarily closed two nuclear power plants. Severnini shows that power lost from these plants was replaced entirely by coal-powered electricity generation, which increased air pollution.

Exploiting this structural break in the electricity mix, Severnini found both a decline in air quality, and a reduction in birth weights.

Severnini’s methods — which took into consideration the geographical and temporal variation in exposure to the additional pollution — could be used to estimate future health impacts in nations that are closing nuclear plants and replacing them with plants using coal and other fossil fuels such as Germany, Japan, and the USA.

Where the normal operation of coal plants results in significant, measurable health impacts, the Fukushima accident — the second worst in history — will have no quantifiable impact on public health. And yet, in the wake of the 2011 Fukushima accident, Japan closed its nuclear plants and has indicated it will build dozens of new coal plants to replace them [7].

Germany has followed Japan in replacing its nuclear plants with fossil fuels. As a result, Germany’s carbon emissions rose for the second year in a row last year, and coal accounted for 40% of its power generation [8].