ScienceDaily (Jan. 6, 2010) — The volcanic eruptions thought responsible for Earth's largest mass extinction -- which killed more than 70 percent of plants and animals 250 million years ago -- is still taking lives today. That's the conclusion of a new study showing, for the first time, that the high silica content of coal in one region of China may be interacting with volatile substances in the coal to cause unusually high rates of lung cancer. The study, which helps solve this cancer mystery, appears in ACS' Environmental Science & Technology.

David Large and colleagues note that parts of China's Xuan Wei County in Yunnan Province have the world's highest incidence of lung cancer in nonsmoking women -- 20 times higher than the rest of China. Women in the region heat their homes and cook on open coal-burning stoves that are not vented to the outside. Scientists believe that indoor emissions from burning coal cause cancer, but are unclear why the lung cancer rates in this region are so much higher than other areas. Earlier studies show a strong link between certain volatile substances, called PAHs, in coal smoke and lung cancer in the region.

The scientists found that coal used in parts of Xuan Wei County had about 10 times more silica, a suspected carcinogen, than U.S. coal. Silica may work in conjunction with PAHs to make the coal more carcinogenic, they indicate. The scientists also found that this high-silica coal was formed 250 million years ago, at a time when massive volcanic eruptions worked to deposit silica in the peat that formed Xuan Wei's coal.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by American Chemical Society.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Large et al. Silica-Volatile Interaction and the Geological Cause of the Xuan Wei Lung Cancer Epidemic. Environmental Science & Technology, 2009; 43 (23): 9016 DOI: 10.1021/es902033j

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

enlarge

Coal from China's Xuan Wei County, widely used for cooking and heating, may contribute to unusually high rates of lung cancer among women in the region. (Credit: US Department of Energy)

Related Stories

World's Biggest Extinction Event: Massive Volcanic Eruption, Burning Coal and Accelerated Greenhouse Gas Choked out Life (Jan. 25, 2011) — About 250 million years about 95 per cent of life was wiped out in the sea and 70 per cent on land. Researchers now believe they have discovered evidence to support massive volcanic eruptions burnt ...  > read more

New Culprit in Earth's Massive Extinction: Mercury (Jan. 9, 2012) — Researchers have discovered a new culprit likely involved in Earth's greatest extinction event: an influx of mercury into the ...  > read more

New Process Promises To Reduce Costs Of A Clean-Coal Technology (July 16, 2007) — Scientists in China are reporting an advance in clean-coal technology that could substantially reduce the cost of producing clean-burning fuels from underground deposits of coal. In a study scheduled ...  > read more

Coal-Mining Hazard Resembles Explosive Volcanic Eruption, Study Shows (Oct. 1, 2009) — Worldwide, thousands of workers die every year from mining accidents, and instantaneous coal outbursts in underground mines are among the major killers. But although scientists have been ...  > read more

Search ScienceDaily