8:05am

Tue April 17, 2012
Health and Welfare

Correlations between Mining and Health

The scholar who has done the most to connect mountaintop removal coal mining with public health issues explained and defended his work last week during a lecture at Morehead State University. The studies by Michael Hendryx and his colleagues at West Virginia University have become controversial because they show correlations between coal mining and public health, not that mining causes health problems. Showing the relationship between two separate things iscorrelation; showing that one thing causes another is causation.

Hendryx said factors that have the most impact on public health are really basic things, including education, income and poverty. In Central Appalachia, which includes Eastern Kentucky, upper East Tennessee, the southern half of West Virginia and southwest Virginia, those factors are all lowest in places where the heaviest mining occurs. His initial analysis found that mortality rates in the coal-mining region of Central Appalachia are 97 percent higher than in the rest of the region. Among the obvious causes are high rates of poverty, smoking, diabetes and obesity, but Hendryx said he and his research team found that “There’s something left over that’s unique to mining environment” after controlling data for those other factors.

High rates of chronic heart, lung and kidney disease, and some types of cancer, “are concentrated most in those areas where mining takes place, especially mountaintop mining,” Hendryx said.

The same patterns are seen with birth defects. From 1996 to 2003, birth defects were reported in 235 of every 10,000 births in counties with mountaintop removal mining, compared to 183 in counties with other types of coal mining and 144 in counties without it. The study found a 63 percent higher risk of birth defects in mountaintop-removal mining areas over non-mining areas.

Though birth defects were seen in all organ systems, heart defects were the most prevalent. Over time, heart and lung defects occurred 181 percent more in areas where mountaintop removal mining occurs.

Much criticism about Hendryx’s studies comes from them being about correlations, not causations.

“Dr. Michael Hendryx is an anti-coal ideologue who is masquerading again as an ‘objective researcher’,” Kentucky Coal Association President Bill Bissett said in an email. “From speaking engagements to environmental activists to a failed attempt to influence the Kentucky General Assembly, his research always comes to a conclusion against the mining of coal to fit his personal bias and political objectives."

In an editorial in West Virginia’s State Journal, Bissett said Hendryx uses public health data to “make leaps of causality that the unhealthy lifestyles in Appalachia are connected to coal mining.”

At Morehead, Hendryx noted several times that his studies reveal correlations, and said he would be the first to admit the studies are limited. But he also said the studies don’t reveal just one set of correlations, but an entire pattern of correlations.

“We have a correlation that shows the people that live in these areas have this set of health problems, they don’t have this other type of health problems,” Hendryx said. “It’s not just because of smoking or poverty or age. It’s stronger as levels of mining go up, it’s stronger as levels of mountaintop mining increase.”

He added that mining-specific effects for diabetes go away when studies are controlled for age, weight and other health indicators. Those mining-specific effects don’t go away for some cancers, chronic heart, lung and kidney disease or birth defects.

Hendryx said he’s now working with other researchers at WVU and the U.S. Geological Survey to find environmental evidence to support the correlations he’s found in his previous studies.

The USGS is collecting air, water and soil samples from mountaintop mining areas. Hendryx will analyze the data from those collections. He said this study is different from past studies because collections are being made in residential areas. Most other studies haven’t done that, he said.

Dust samples have been taken at non-mining areas and mountaintop removal mining areas, and examination of those samples reveals they consist mostly of what would be in overburden, or rock and other material exploded to expose coal seams. The process releases heavy metals like silicon, sulfur, aluminum and iron, Hendryx said.

Animal studies have been conducted with some samples. Hendryx said scientists allow rats to inhale an amount of the dust equivalent to three years of exposure. In one study, cells in the rats’ hearts died, and in another, the blood vessels were damaged, reducing their ability to expand and contract normally.

Hendryx acknowledged that the studies are very preliminary, but said they will be helpful in going beyond ecological studies that only show correlations between where people live and the health outcomes. He said environmental studies would eventually be linked to direct biological measures.

He said all of his studies are limited, but that even if the exact causes of Appalachian health disparities aren’t known, it would be “unethical and inappropriate” to ignore the correlations.

“We need to act now and do the things that we can to try and improve those conditions,” he said.

Ivy Brashear, a native of Viper, Ky., and a former reporter for the Hazard Herald, is a graduate student in the Department of Community and Leadership Development in the College of Agriculture at the University of Kentucky and an assistant in the Institute for Rural Journalism and Community Issues, based in UK’s College of Communication and Information.