[LINK] "Chinese Coal Formed During Earth’s Greatest Extinction Is Deadly"

[rfmcdonald]

China, it turns out, can't realistically be held to account for much of its coal's impact on the environment, Wired Science's Alexis Madrigal reports.

A seam of coal formed 250 million years ago during the worst extinction event on record appears to be responsible for the anomalously high lung cancer death rates among women in the rural Chinese county of Xuan Wei in Yunnan Province.

It’s long been known that the lung cancer mortality rates in the region were the worst in the world among female nonsmokers and some anomaly in the coal had been suspected. Lung cancer mortality in the region is up to 20 times the Chinese average. But it’s only in recent years that scientists have focused in on silica in the form of very fine quartz as the mineral that makes burning the stuff so deadly.

Now, in a paper published in December in Environmental Science and Technology, Chinese, British and American researchers have proposed a link between the silica in the coal and the massive event that nearly wiped out life at the Permian-Triassic boundary.

“What we’re saying is that the geologic and climatic events that nearly extinguished life 250 million years ago is still having an impact because its imprint is in the coals that the people are using,” said Bob Finkelman, a geologist at the University of Texas, Dallas. “They are inhaling this material with nanoquartz that was precipitated 250 million years ago and in a sense it’s extinguishing life in the community.”

[. . .]

“Even when you look at coal from a small region, there’s enough variation in the properties that you can’t just call it all coal and expect it to have the same health effects when you burn it,” said Donald Lucas, a physical chemist at Lawrence Berkeley National Laboratory. Lucas co-authored a paper on the nanoquartz in Xuan Wei’s coal with geologist Linwei Tian of Chinese University of Hong Kong who did pioneering work on the subject.

What Finkelman’s work provides is a plausible account of why this particular coal may be enriched with silica. While there are several hypotheses for what caused the mass die-off at the Permian-Triassic boundary 250 million years ago, a major volcanic episode is likely to have contributed to the phenomenon. Massive amounts of gases leaving Siberian basalts are believed to have radically altered the geochemistry of the atmosphere.

“It lead to highly acidic rain which denuded life on the surface of the earth and acidified the rivers and the oceans,” Finkelman explained. “It was so intense that they believe it actually dissolved a lot of the rocks on the surface, mobilizing the silica.”