Air Pollution's Impact On The Smokies' Environment

The Great Smoky Mountains National Park, which straddles the border between North Carolina and Tennessee, is one of the most popular national parks in the US, attracting over 14 million visitors in 2021. However, the park and its visitors are facing a serious threat from air pollution. The burning of fossil fuels, industrial emissions, and vehicle exhaust all contribute to a haze that hangs over the mountains, obscuring the views and causing a range of health and environmental issues. This haze, which can be as harmful as cigarette smoke, is caused by a combination of sulfur and nitrogen oxide emissions, which react with water vapour and ammonia in the atmosphere to form particulate matter. This haze has been linked to respiratory illnesses and can have long-term health effects on those who breathe it in. In addition, the high levels of nitrogen and sulfur deposition in the park have led to acid rain and stream acidification, damaging plant life and waterways and threatening the native brook trout population. While there have been some improvements in air quality in recent years, largely due to the retirement of several coal plants, more action is needed to protect the fragile ecosystem of the Great Smoky Mountains and the health of those who visit and live nearby.

The impact of fossil fuel burning

The Great Smoky Mountains National Park is affected by air pollution from the burning of fossil fuels. This includes coal, oil, and gas, which are mostly emitted from sources outside the park, such as power plants, industry, and automobiles. The height and structure of the mountains, combined with weather patterns, trap and concentrate these pollutants, degrading the park's natural resources and harming human health.

The burning of fossil fuels produces tiny airborne sulfate particles, which scatter light and reduce visibility. This haze, distinct from the natural mist-like clouds of the Smokies, obscures views and affects how well and how far one can see. The average visibility in the southern Appalachians has decreased by 40% in winter and 80% in summer since 1948. Visitors to the park are impacted by this, as scenic views are an important part of their experience.

In addition to the visual impact, the ground-level ozone created by the interaction of nitrogen oxides and hydrocarbons in the presence of sunlight poses a threat to human health. Ozone is a powerful respiratory irritant and can cause coughing, sinus inflammation, chest pains, scratchy throat, and even permanent damage to lung tissue. It is especially harmful to children, the elderly, and those with existing health problems.

To address these issues, the Clean Air Act was passed in 1970, establishing policies to preserve, protect, and enhance air quality. The Act designated national parks exceeding 6,000 acres as Class I areas, worthy of the greatest degree of air quality protection. While there have been improvements, such as reduced haze and acid rain, more efforts are needed to reach the EPA's goal of restoring natural visibility conditions in Class I areas by 2064.

The health risks of air pollution

Air pollution is a major threat to human health and the environment. It is caused by the presence of contaminants in the atmosphere, such as dust, fumes, gas, mist, odour, smoke or vapour, which can have detrimental effects on the body when inhaled. These pollutants can enter the body through the respiratory tract and lead to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells. This can impact almost every organ in the body, including the lungs, heart, and brain, ultimately leading to disease.

The specific diseases most strongly linked to air pollution exposure include stroke, ischaemic heart disease, chronic obstructive pulmonary disease, lung cancer, pneumonia, and cataract (in the case of household air pollution). There is also evidence to suggest that air pollution exposure is linked to an increased risk of adverse pregnancy outcomes, other cancers, diabetes, cognitive impairment, and neurological diseases. Fine particulate matter, which can penetrate deep into the lungs and enter the bloodstream, is a particularly important source of health risks.

Children, the elderly, and pregnant women are especially vulnerable to the health effects of air pollution. Additionally, people living in areas with high levels of air pollution, low socioeconomic neighbourhoods, or near industrial sources of pollution may be at higher risk. Genetic factors, comorbidities, nutrition, and sociodemographic factors can also influence an individual's susceptibility to the health impacts of air pollution.

In the case of the Great Smoky Mountains National Park, air pollution has been a persistent issue, mainly originating from outside sources such as power plants, industry, and automobiles. The burning of fossil fuels, inadequate pollution control equipment, and the concentration of pollutants by the mountains' physical structure and weather patterns have contributed to the problem. Visitors to the park have experienced reduced visibility, respiratory irritation, and potential long-term health effects from exposure to ground-level ozone and fine particulate matter.

While there have been improvements in air quality in recent years, with reduced acid rain, haze, and unhealthy days, more work needs to be done to protect public health and the environment from the harmful effects of air pollution.

Visibility reduction and the effect on tourism

The Smokies, or the Great Smoky Mountains National Park, is the most-visited national park in America, attracting over 14 million people in 2021. Visitors to the park expect to find clean air and clear views. However, air pollution, primarily caused by the burning of fossil fuels, has been obscuring the views and negatively impacting the experience of tourists.

The natural haze that gives the Smokies their name is being exacerbated by human-created pollution, creating a haze that can be as harmful as cigarette smoke to those who breathe it. This haze is caused by the interaction of sulfur and nitrous oxide emissions, primarily from industrial plants and power plants, with water vapour and ammonia in the atmosphere. The height and physical structure of the mountains, combined with predominant weather patterns, trap and concentrate these human-made pollutants, creating a whitish haze that obscures the views.

This reduction in visibility not only affects how far one can see but also reduces how well one can see. The haze caused by pollution can make colours appear washed out and obscure landscape features. On the haziest days, visibility can be reduced to under nine miles, and even on clearer days, it is limited to 46 miles or less, far from the natural visual range of about 110 miles. This degradation of visibility negatively impacts the experience of tourists who come to the park to enjoy the scenic views.

In a 1996 survey, 74% of summer visitors to the Smokies stated that clean air was "extremely important" to them during their stay, while 84% said that scenic views were "extremely important". The reduction in visibility due to air pollution, therefore, has the potential to deter tourists from visiting the park, impacting the local economy.

While there have been some improvements in air quality in recent years, with visibility increasing from 25 miles in 1990 to 46 miles today, more efforts are needed to meet the Clean Air Act goal of no human-caused impairment. The National Park Service is working to address the issue through science, policy, and planning, and partnerships with local communities have also been instrumental in driving change. These collective efforts give hope for further improvements in visibility and a better experience for tourists visiting the Smokies.

The role of wind currents in transporting pollutants

The Great Smoky Mountains National Park in North Carolina and Tennessee is affected by air pollution transported by wind currents from urban areas, industrial sites, and power plants. The height and physical structure of the mountains, combined with predominant weather patterns, trap and concentrate human-made pollutants in and around the national park.

The wind currents moving toward the southern Appalachians carry pollutants from both near and far sources. The mountains act as a natural barrier, trapping the pollutants in the surrounding area. The physical structure and height of the mountains, combined with the prevailing wind patterns, create an ideal condition for the accumulation of human-made pollutants. This leads to a degradation of the park's natural resources and a negative impact on visitor experiences.

The burning of fossil fuels, such as coal, oil, and gas, is the primary source of pollution in the region. Inadequate pollution control equipment in power plants, factories, and automobiles contributes significantly to the issue. The wind transports these pollutants, including sulfur and nitrogen compounds, into the park, where they cause harm to the natural environment and impact the health of those who visit.

The air pollution in the Great Smoky Mountains has led to a reduction in visibility, with a whitish haze obscuring the once-scenic views. The average visibility in the southern Appalachians has decreased by 40% in winter and 80% in summer since 1948. This haze is caused by tiny airborne sulfate particles produced by the burning of fossil fuels, which scatter light and reduce visibility. The annual average visibility in the Great Smoky Mountains National Park is now 25 miles, compared to the natural condition of 93 miles.

In addition to the impact on visibility, the wind-borne pollutants also have detrimental effects on the park's natural resources. The high levels of nitrogen and sulfur deposition lead to acid rain and acid clouds, with pH levels as low as 2.0. This acidification process harms the forest soils, streams, and vegetation. The release of toxic aluminum, for instance, poses a threat to both vegetation and stream life. The nitrogen saturation in certain high-elevation soils limits the availability of essential nutrients for plants, further compounding the issue.

The impact of air pollution on the region's waterways

The impact of air pollution on the waterways of the Great Smoky Mountains National Park is a pressing issue. The park, which spans North Carolina and Tennessee, is known for its natural beauty, but its streams and waters are under threat from human-made pollution.

Nitrogen and sulfur compounds are major contributors to the air pollution affecting the waterways. These compounds, emitted primarily by industrial sites and power plants, as well as traffic, can cause eutrophication and acidification. Eutrophication increases soil and water nutrients, leading to changes in species composition and growth patterns. Acidification, on the other hand, leaches important cations from soils, lakes, ponds, and streams, reducing habitat quality. The park has been found to receive the highest level of acid deposition of any monitored national park, with high ridge-top ecosystems being particularly vulnerable.

The impact of these compounds on the waterways is significant. Streams in the park have been designated as "impaired" due to acidification, with some streams having nitrate levels approaching the public health standard for drinking water. The increased nitrogen saturation in the waterways also reduces the availability of nutrients for plants and can lead to the release of toxic forms of aluminum, further endangering aquatic life such as the native brook trout.

In addition to nitrogen and sulfur compounds, other pollutants such as mercury and pesticides are also of concern. These toxic contaminants can travel long distances and accumulate in the tissue of organisms, leading to reduced reproductive success, impaired growth, and decreased survival rates. Mercury concentrations in some fish sampled at the park have exceeded the threshold for human consumption, posing potential health risks to visitors who fish in these waterways.

The air pollution affecting the waterways of the Great Smoky Mountains National Park is not only detrimental to the environment but also to human health and well-being. Visitors to the park, who come to enjoy the scenic views and natural beauty, are instead exposed to poor air quality that can have long-term health effects.

Addressing the impact of air pollution on the waterways requires a multi-faceted approach. While the Clean Air Act and the efforts of organizations like the National Park Service and the Southern Alliance for Clean Energy have led to some improvements, more stringent measures are needed to protect the fragile ecosystems of the Great Smoky Mountains.

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