Forget, for a moment, the debate over “clean coal” and “dirty coal,” and consider the rock’s impact on human health. Wired.com reported on Thursday that coal being mined in China is linked to an unusually high lung cancer mortality rate among women and nonsmokers in the rural Chinese county of Xuan Wei in Yunnan Province.
Alexis Madrigal reports that in a paper published in December in Environmental Science and Technology, Chinese, British and American researchers have ferreted out a link between the silica in the coal and the massive event that nearly wiped out life at the Permian-Triassic boundary.In developing areas, people inhale particulates from coal burned in rudimentary stoves for heating or cooking. This produces health problems, in fact the World Health Organization estimates that 1.6 million people die each year as a result of indoor air pollution, notes Madigral.
And depending on where and when in the Earth’s crust it was formed, coal from different deposits burns differently—some coal is dirtier than other coal.
The coal in Xuan Wei is mined from a seam formed 250 million years ago during the worst extinction event on record. Bob Finkelman, a geologist at the University of Texas, Dallas, and one of the report’s authors, believes the coal is particularly harmful to human health because it carries unusually high levels of silica that can be traced back to a major volcanic episode that is likely to have contributed to the catastrophic changes on the planet at the Permian-Triassic boundary 250 million years ago.
And the researchers think that the coal burned in Xuan Wei is the cause for the higher cancer deaths there—setting it apart from other regions of China were residents also inhale smoke from coal burned for heating and cooking.
Whatever the cause, the next step is to mitigate the health effects for which this coal appears to be largely responsible. Cleaner-burning stoves, alternative fuel sources and electricity will go far to improve human health in Xuan Wei, and they are already started to be used, but epidemiologists will continue to study this uniquely harmful coal and try to determine ways to reduce its harm.