Appalachian Mountain Air: Good for the soul…but what about the heart?

by Allyson Green on March 11, 2013

Imagine being crammed into the back seat of a car winding its way up the side of a mountain (maybe winding a bit too fast for comfort), sneaking glances out the window and over the cliff, wishing there was a guardrail between you and that cliff. You see a clearing in the trees up ahead where the road comes to its highest point, and knowing there must be a scenic overlook, you convince the driver to stop for a picture just as you’re feeling the need for some fresh air and solid ground. You jump out of the car and take a deep breath before soaking in the scenery.  If this mountain road happened to be Route 160 crossing over Black Mountain from Kentucky to Virginia here in the U.S., the fresh air might settle your stomach, but you’ll find something unsettling about magnificent scenic view before you. And according to a recent study out of West Virginia University, that fresh mountain air in your lungs might actually unsettle your cardiovascular system if you breathe it for more than a year.

From that scenic overlook atop Black Mountain, you’ll see the rolling Appalachian Mountains in the distance. But a closer look reveals a stark lack of mountain peaks in the foreground.

What was once a green, forested mountain peak is now a sprawling coal mine. Coal produces 30.3% of the world’s energy and 45% of the electricity in the U.S. Much of that coal is still mined using underground methods, but surface mining is on the rise, especially in the Appalachian region of the U.S. where the number of surface mines grew from 652 to 689 between 2010-2011. Mountaintop removal surface mining (MTR), the kind you see on Black Mountain, basically scrapes the top of a mountain off to get to the underlying coal, like taking the top layer off a piece of cake to expose the precious frosting layer in the middle.

Taking the top off a mountain is no small task. It requires massive machinery and large amounts of explosives. The process releases tiny particles into the air that can be swept down the slopes to neighboring communities—communities that have higher mortality rates from chronic cardiovascular disease than non-MTR communities in the region. We know that smoking, obesity, and diet, are important risk factors for cardiovascular disease, but studies have linked heart disease with proximity to coal mining sites even when other risk factors are accounted for. So, what else could be contributing to cardiovascular problems near MTR sites? The researchers from West Virginia University suggest it could be those tiny particles produced by MTR that get into the lungs and into the smallest blood vessels in those residents’ bodies.

To test the effect of this particulate matter on cardiovascular function, the researchers collected air samples from two different sites a mile away from an MTR site in West Virginia. Since communities near MTR sites are often old coal camps built as company towns right next to underground mines, it’s not uncommon to find houses within a mile of an active mine now or even right in someone’s backyard like the picture below. This fact helps make the air sample relevant to real-life exposures.

After testing the sample to see what kind of particles it actually contained (mostly sulfur and silica, by the way—major components of the actual rock from the mountain), the researchers then exposed rats to the air sample by mixing it with a saline solution and injecting it into the trachea. Now, this is where the study strays from real-life exposures: rats are not humans, and particulate matter doesn’t generally enter our lungs through a needle. We usually just inhale it.

This doesn’t mean we should dismiss the results of the research, though. Both the use of animal models and the injection exposure technique (called intratracheal instillation) are common research methods that allow us to better understand physiological responses to toxic substances like particulate matter. It’s not a perfect model—it won’t tell us exactly what could happen to a real person breathing in this air—but no such thing exists in science. We use models to make predictions, knowing those models can’t represent everything perfectly (Note: Remember making molecules out of toothpicks and marshmallows in school? That was a model that helped you visualize how atoms come together to make things like water… but we know that a water molecule doesn’t look and act exactly like a marshmallow-toothpick sculpture).

After these rats were exposed to the particulate matter from the MTR site, researchers performed standard tests to measure cardiovascular function. Their results showed some significant differences between rats exposed to the MTR particulate matter and those who were not. Tiny blood vessels called arterioles in heart and the mesentery (tissue supplying blood to the small intestine) did not dilate and constrict normally after exposure.

This evidence of blood vessels not opening and closing like they should is the first to connect MTR exposures to an actual physiological response linked with cardiovascular disease. With this being the first of hopefully many studies looking more closely at this relationship, it raises many more questions to be explored:

  • How much particulate matter are residents near MTR sites actually exposed to?
  • How much particulate matter do humans need to be exposed to before seeing this kind of response in blood vessels?
  • How does particulate matter exposure interact with other cardiovascular risk factors like smoking and obesity?
  • What other health effects are linked with this particulate matter exposure?
  • Does particulate matter from all MTR sites elicit the same response?
  • How does the response differ in adults and kids, in men and women, in young and old folks?
  • What is the cumulative impact of being exposed to not just particulate matter but to exhaust from machinery and coal trucks, mine run-off into local streams, and potentially higher stress levels over many years of living next to an MTR site?

Studies like this using animals in a lab rather than humans in real-life scenarios are important in guiding future research. Humans are complicated, as are real-life exposures to toxic substances like particulate matter. Maybe the next study can build from this research with MTR community residents  strapping on air monitors, heart rate monitors, and blood pressure cuffs to measure their actual exposures and responses. Or maybe we’ll start to see real-time air sampling labs springing up across the hollows and scenic overlooks of Appalachia. In the meantime, we can add cardiovascular impacts to the list of hidden costs associated with flipping on the lights. And we can keep exploring these mountain backroads, knowing that as our heart rate and car sickness rises with altitude, our temporary ills don’t compare with the chronic conditions faced by residents down below.

David Reedy March 11, 2013 at 1:30 pm

Well written. I liked how you clearly pointed out the drawbacks of rats vs humans and then made a strong argument for the importance of these rat studies.

Allyson Green March 11, 2013 at 2:21 pm

Thanks, David! The usefulness of animal studies is not something I ever thought about before taking a physiology class–I just figured we should go straight to the source and work with humans! Apparently that’s not so easy… :)

Mary Ellen Anderson March 11, 2013 at 3:15 pm

Well written, easily understood, and important for informing most of the general population of the cost of their comforts. A once lovely area is essentially being ravished at the cost of the land and health of its inhabitants. We should be able to do better.

Allyson Green March 11, 2013 at 8:33 pm

The environmental, social, and health effects are felt in other coal mining areas, too (out west and in IL), but Appalachia has been leading the way in fighting for well-being. Someday we will do better! Thanks for reading!

Michael March 11, 2013 at 7:23 pm

The price of coal is going down as utilities switch to natural gas and the remaining coal burners prefer the cleaner stuff from the Powder River Basin. I wonder if the proceeds from Appalachian mining match the costs anymore?

Allyson Green March 11, 2013 at 8:30 pm

It sounds like the costs have finally caught up with the proceeds in Appalachia (according to this Bloomberg piece: http://www.bloomberg.com/news/2012-03-21/appalachian-coal-fights-for-survival-on-shale-boom-commodities.html), but industry still wants Appalachian coal because it burns better (although dirtier) and is cheaper to ship in the eastern U.S. (http://www.statejournal.com/story/20881915/appalachian-basin-coal-seems-to-be-struggling-more-than-coal-from-other-regions). It’ll be interesting to see how fluctuating prices and new regulations on cross-state air pollution affect coal production and use this year!

Angela March 13, 2013 at 7:18 am

Hi Allyson! Thank you for writing about coal at a time when it appears to be coming back into fashion as an energy source (e.g. in Germany, after the Fukushima disaster). I liked the intro ‘teaser’ with the fresh, but dangerous mountain air, and also, like David, the explanations around the rat studies, and how these might be extended through experiments involving humans.

Allyson Green March 13, 2013 at 6:48 pm

Thanks, Angela! Interesting to hear that coal is seeing a resurgence in Germany after Fukishima. It would be fascinating to sit in on conversations where people are weighing the risks and benefits of coal vs. nuclear both on the policy end, personally, and throughout the energy industry. What makes people decide one is worth the risk and another is not?

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