The limits of scientific certainty and the need for positive change

Michael Hendryx is a pioneering research investigator focused on the impacts of uneven environmental exposures faced by socioeconomically disadvantaged groups. In 2006, Michael started a research program on public health disparities for people in Appalachia who live in proximity to coal mining, with a focus on mountaintop removal. This research has shown that people who live close to mountaintop removal are at increased risk for a wide set of health problems including respiratory illness, cardiovascular disease, birth defects, cancer, and others. Michael spoke at TEDMED 2017, and you can watch his Talk here.


I have committed the last 12 years of my professional life to conducting research on public health conditions in Appalachian coal mining communities. I have focused in particular on a highly destructive form of surface coal mining called Mountaintop Removal. As I described in my TEDMED talk, mountaintop removal involves the heavy use of explosives to reach the buried coal, wholesale destruction of forests and streams, and production of water and air pollution over a large footprint in central Appalachia that is home to over a million people.

MTR site above a town. (Source: Paul Corbit-Brown)

As I write this blog, I am surprised to see these words on the screen: Appalachian coal mining has become a central part of my research career. I am not from Appalachia. I was born in Illinois and have spent most of my life in the Midwest and West. I knew very little about coal mining or its environmental, ecological, economic and public health harms before taking a faculty position at West Virginia University in 2006. But as I learned about the issue, and began to examine it from a public health perspective, I gradually became convinced that this mining practice was truly harmful to the health of nearby community residents.

In retrospect it may seem obvious that this is so, but the work faced two constraints: the impossibility of conducting the “perfect” study to establish definitive cause between mining and public health, and the doubt and resistance, not only from politicians and the industry (predictable) but from research colleagues who were sure (without actually studying the issue) that the health problems must be due to the usual suspects of smoking, obesity and poverty that plague mining-dependent communities. Certainly blowing up mountains over people’s heads couldn’t harm their health! Could it?

As I contemplated my TEDMED talk and considered the message I wanted to offer, I realized that I wanted to raise awareness about mountaintop removal throughout the TEDMED community, but I also wanted to say something to the larger scientific community that was not dependent on a single environmental issue, but that perhaps could aspire to a larger resonance. Initially, I wasn’t sure myself what this would be, but I knew it was something about the tension between science and advocacy, which morphed into a statement about the limits of science in the face of an ethical imperative. From someone like me who prides himself on the power of empirical evidence, this is quite a statement about scientific limits!

It’s a well-known idea in environmental science: the precautionary principle. If there is evidence that health is impaired, and if there is evidence of environmental risk that may reasonably contribute to that impairment, then appropriate action is necessary to reduce the risk even if all causal links are not understood.

Since 2006 I, with many co-authors, have published more than 30 research papers in academic journals that document environmental and public health conditions in mining communities. For me the answer is undeniable, despite the lack of the perfect causal study: mountaintop removal mining is harmful to public health. It should be discontinued to protect human health. I think we have reached the point where further studies are frankly unnecessary, except to keep the issue in the public eye. Additional studies carry the risk of doing a disservice to the people who live in these communities, as we can study the issue to death without ever convincing the politicians and industrialists who are motivated and rewarded by doubt. As I said in my talk, “There can always be doubt, if doubt is what you seek.”

Instead of continuing to document problems, it is past time to move to solutions. It is a fact that the physical reserves of recoverable coal in Appalachia are in sharp decline. It is a fact that the world is moving away from coal to other energy sources. Coal mining as an economic force in Appalachia is subsiding. This has nothing to do with a so-called ‘war on coal.’ It is a consequence of geological and economic reality.

The solutions, in my view, lie in the power, imagination and energy of the people of Appalachia. I have encountered many examples of efforts underway to promote a transition to a strong and sustainable economy for the region as coal approaches its death rattle. I anticipate that these incipient efforts will eventually lead the way to greater opportunity and health for the region. Vested political and economic interests still refuse to acknowledge or support the change, but eventually they will have no choice.