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Hurricane Florence: déjà-vu all over again

Translational Ecology
by Bill Schlesinger
Mon Sep 24th, 2018

Adapted from an op-ed in the Raleigh News and Observer, 21 September 2018

We have dramatically reduced illness and mortality from infectious disease through the miracles of modern medicine, vaccination, and public health education. Now environmental exposures challenge future health outcomes. In North Carolina, Hurricane Florence provides a stark demonstration of how runoff and overflows can contaminate waterways with hog waste and coal-ash leachates.

Just as state legislators in North Carolina seem destined to roll back the regulation of confined animal feeding operations (CAFOs) and the EPA seeks to loosen the standards for emissions from coal ash ponds, driven by corporate pressures to foster economic growth, medical researchers find significant health impacts from these operationsTwo papers from physicians in the Duke University Medical School are of particular note in the latest issue of the North Carolina Medical Journal.

Reviewing various studies published over the past decade, Drs. Julia Kravchenko and H. Kim Lyerly found higher rates of mortality in populations located close to coal ash ponds, which are a source of arsenic, selenium, vanadium and other metals that leach into local surface and groundwater supplies. Through extensive chemical analysis, Drs. Jennifer Harkness and Avner Vengosh of Duke’s Nicholas School of the Environment link high concentrations of these elements in surface waters to leakage from coal-ash ponds. High runoff waters from Hurricane Florence caused a major coal ash contamination of the Cape Fear River. Storage of coal ash is normally located near electric utility power plants, which are themselves a source of air pollution by toxic metals and ozone.

Florence also caused a number of hog-waste ponds to overflow into regional waterways, contaminating their waters with nitrogen and bacterial pollution from fecal matter. The citizens of North Carolina have experienced this before, especially during Hurricane Floyd. Unfortunately, the elected officials in the State seem to cast a blind eye to contamination from Confined Animal Feeding Operations (CAFOs), which house chickens and hogs.

Upstream of Wilmington, a chemical company has discharged toxic perfluoroalkyl and polyfluoroalkyl substances, or PFAS, including a compound known as GenX, to the Cape Fear River for nearly 40 years. No one wakes up in the morning tasting these molecules in their water, but they are known carcinogens that can be expected to increase the rate of cancer in humans. These emissions should have been halted by appropriate enforcement of the Clean Water Act and the Toxic Substances Control Act. One can only wonder how these chemicals were dispersed by the runoff waters from Hurricane Florence.

Once a model for other states, North Carolina’s Clean Smokestacks Act of 2002 regulated gaseous emissions from power plants, and substantially improved air quality across North Carolina, resulting in lower rates of mortality from air pollutant gases in recent years. But citizens of North Carolina are still exposed to significant air pollution, especially from fine particles derived from ammonia emissions from agricultural operations in the eastern counties. Dr. Julia Kravchenko and her colleagues found higher mortality in communities, defined by zip code, that were in close proximity CAFOs in eastern North Carolina.

In addition to water pollutants, CAFOs are known sources of a variety of air pollutants, including ammonia and hydrogen sulfide. These results are consistent with observations of higher morbidity due to fine particulate air pollution, which forms from reactions of these gases to form particles in the atmosphere. Globally, air pollution exposure to fine particles is estimated to kill more than 3 million people each year, through increased rates of cardiovascular disease and stroke. North Carolina contributes its share.

Health problems associated with environmental contamination are not new. The origin of most contaminations stems from corporate practices and strong lobbying to continue them. Often the assumption is that flooding does not occur very often, but we’ve seen widespread contamination from two hurricanes within the past couple of decades. Many of the contaminations are focused in communities of color and low income, as if these social groups do not matter. Greater economic activity can benefit all citizens, but only if all the citizens are alive to enjoy it.


Harkness, J.S., B. Sulkin and A. Vengosh. 2016. Evidence for coal ash ponds leaking in the southeastern United States. Environmental Science and Technology 50: 6583-6592.

Kravchenko, J. and 4 others. 2018. Mortality and health outcomes in North Carolina communities located in close proximity to hog concentrated animal feeding operations. N.C. Medical Journal 79: 278-288.

Kravchenko, J. and H.K. Lyerly. 2018. The impact of coal-powered electrical plants and coal ash impoundments on the health of residential communities. N.C. Medical Journal 79: 289-300.

Ruhl, L. and 6 others. 2012. The impact of coal combustion residue effluent on water resources: A North Carolina example. Environmental Science and Technology 46: 12226-12233.

Schwartz, G.E. and 7 others. 2016. Leaching potential and redox transformations of arsenic and selenium in sediment microcosms with fly ash. Applied Geochemistry 67: 177-185.