The United States produces nearly one-fifth of the world’s coal-fired electricity and ranks second in gigawatt-hours produced from coal power. The developing nations of China and India are first and third, respectively.

According to a 2014 Environment America report, the six dirtiest plants in the U.S. in terms of carbon emissions are as follows, starting with the dirtiest: Plant Scherer, Macon, Georgia; Gibson Generating Station, Owensville, Indiana; Bruce Mansfield Power Station, Shippingport, Pennsylvania; Rockport Generating Station, Rockport, Indiana; James M. Barry Electric Generating Plant, Mobile, Alabama; and General James Gavin Power Plant, Cheshire, Ohio. These plants also release hefty amounts of mercury, sulfur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2) and particulate matter. Because the prevailing winds come from the west and southwest, the Northeast is the recipient of the toxic emissions from at least four of these power plants as well as numerous others. The emissions from burning coal contain many toxic compounds, but the main compounds are SO2 (precursor to acid rain), NOx (NO, and NO2, precursors to ozone and acid rain), mercury, carbon dioxide (CO2) and particulate matter (PM).

Although much could be written about all these pollutants, this article will address acid rain and to some extent mercury. Acid rain was a common term heard in the 1980s and 1990s until other issues took the spotlight, but acid rain is still very much a problem in the U.S. and particularly the Adirondack Mountains. Scientists in the U.S. have been documenting ecological damage caused by acid rain since the 1970s in the region most affected — the Northeast.

“In 1990, Congress amended the Clear Air Act and instructed the U.S. Environmental Protection Agency (EPA) to create the nation’s first acid rain control program. In 1992, the Bush Administration boasted that the new program would ‘end acidity in Adirondack lakes and streams.’ But many recognized right away that the program would be inadequate to stop the destruction in the Adirondack Park and the nation’s other sensitive ecosystems.” (http://www.adirondackcouncil.org/page/acid-rain-86.html).

To make a very long story short, emissions from coal-fired power plants were reduced, but in 1996, the EPA issued a report that stated that the acid rain program would only delay the damage caused in the Northeast, not end it. Acid rain is detrimental to ecosystems in a number of ways, including lowering the pH of some watersheds so they cannot sustain aquatic life, leaching essential minerals out of soil so that forests are severely damaged, leaching mercury out of soils into water so our drinking water as well as fish and birds are contaminated.

A few examples of the damage acid rain has already caused: Many areas in the Northeast have a fish consumption advisory against eating certain fish due to mercury contamination. Studies are being conducted in the Northeast on the mercury contamination of loons, and according to Zoe Smith, director of the Wildlife Conservation Society’s Adirondack Program, “Seventy-five percent of the loons that we sampled were at either moderate or high risk from mercury in their blood.” (https://green.blogs.nytimes.com/2012/06/28/mercury-afflicts-much-loved-loons/?_r=0) Hardwood forest growth in New Hampshire’s Hubbard Brook has been severely impacted because essential minerals have been leached out of the soil by acid rain. Many ponds and lakes in the Northeast do not support aquatic life anymore. I could list many more but for the sake of brevity will not.

Once an ecosystem is acidified, it can take decades to centuries to recover. The SO2 emissions largely responsible for acid rain in the Northeast have dropped significantly since the mid 1990s, thanks to the EPA. Without the EPA, emissions would have continued unchecked, and the damage to the Northeast would be much more extensive. As it is now, “By 2040, according to an EPA report, 43% of the 2,800 lakes and ponds in the Adirondacks are likely to have a pH under 5.0, the critical threshold for most fish and many other species. That is an increase of 27% now.” (http://www.adkmuseum.org/acidrain/problem.shtml) Part of the reason for this is continuing emissions, the fact that most of the Northeast does not have much buffering capacity against acid rain, and most of the buffering capacity has already been compromised. Clearly, emissions need to be further reduced for the health of the ecosystems of the whole Northeast. The technology exists to reduce emissions from power plants, but many of the older plants do not employ this technology.

Acid rain also has an impact on the economy of the Northeast by decreasing crop and timber harvest yields, decreasing maple syrup production (maple trees seem to be especially susceptible to acid rain), and decreasing recreational and sustenance fishing. And none of this addresses the impact on human health, including contamination by mercury (a neurotoxin which is being linked to autism) and the inhaling of particulates present in the emissions that lodge deep into lungs.

“Particulates related to acid rain include fine particles of SOx and nitrates. These particles can travel long distances and, when inhaled, penetrate deep into the lungs. Acid rain and the pollutants that cause it can lead to the development of bronchitis and asthma in children. Acid rain is also believed to be responsible for increasing health risks for those over the age of sixty-five; those with asthma, chronic bronchitis, and emphysema; pregnant women; and those with histories of heart disease.” (http://www.encyclopedia.com/science-and-technology/biology-and-genetics/environmental-studies/acid-rain)

The bottom line is the Northeast (and the whole country) cannot afford to relax existing pollution controls and must strive to implement more stringent controls. Reducing or ignoring pollution controls harms both citizens health and welfare, the economy and the environment. To see what our country would look like without the EPA and pollution control, just look at China and India — countries where people wear respiratory masks just to go outside and where visibility is severely limited due to excessive smokestack emissions. There are many studies being conducted on the health effects of pollution, and it is estimated that 5.5 million people in the world die prematurely due to air pollution, with 200,000 of those deaths in the U.S. (http://www.bbc.com/news/science-environment-35568249) The argument that pollution controls are expensive and hurt the economy does not account for the reality that not reducing pollution has a much higher cost to human health, the economy and the environment.

Cheryl Joyce is a professor of chemistry at Paul Smith’s College in Paul Smiths.