Air Quality

The Air Quality toolbox is a ‘work in progress’ and represents information available to date on this subject. To suggest new materials for inclusion, email Lisa Ronald at


According to the National Research Council, in 1993 visibility in western wilderness was about half of what it would be without air pollution, and in eastern wilderness, about 1/5 of natural conditions. Clean air is necessary for natural ecosystems to properly function inside wilderness. It is also integral to visitor experience as most visitors who come to wilderness areas expect clear views. Yet, many remote areas are affected by air pollution because it can be transported significant distances by winds and atmospheric currents. And, of course, some wilderness areas are nearby urban centers or industrial development which create more direct impacts.

According to the National Survey on Recreation and the Environment, 93% of the public value wilderness for the protection it provides to air quality (this is the single most identified value of wilderness). Indeed, because the Clean Air Act identifies certain wilderness areas as Class I, and because attaining that goal can only be met by also improving the air quality of the surrounding area, wilderness designation is then a source, so to speak, of cleaner air in the surrounding area.

Air Quality and the Wilderness Act

Though maintaining clean air and visibility is important to wilderness character and so is implied as a goal of the Wilderness Act of 1964, air quality management is not mentioned specifically in the Wilderness Act or in any wilderness enabling laws. Protecting air quality is necessary if wilderness is to be managed “so as to preserve its natural conditions” as the Wilderness Act describes. Maintaining air quality in a natural condition is necessary for a wilderness area to retain its “primeval character and influence” as also described in the Wilderness Act.

Preserving Wilderness Character is the mandate of the Wilderness Act. Section 4(b) requires each agency to “preserve the wilderness character of the area …”. The qualities of wilderness character are described in the definition of wilderness found in Section 2(c) of the Wilderness Act. Five qualities are identified: Untrammeled, Natural, Undeveloped, and Outstanding Opportunities for Solitude and a Primitive and Unconfined type of Recreation, and Other Features of Value. Preserving these five qualities preserves wilderness character as a whole. Air quality issues are most closely linked and directly relevant to two of the five qualities of wilderness character: the Natural and Other Features of Value Qualities.

The Natural quality of Wilderness Character is described in the Wilderness Act in this way “… retaining its primeval character and influence…”, and “… protected and managed so as to preserve its natural conditions …” This means that physical and biological functions and processes are not influenced by intended or unintended effects of modern civilization. Air quality in wilderness is natural when it does not contain contaminants caused by modern human activity. When contaminants reach certain levels, they can manifest themselves in damage to the ecosystem, i.e. the natural quality; for example vegetation or fisheries decline.

The Wilderness Act describes the Other Features of Value quality it in this way “may also contain ecological, geological, or other features of scientific, educational, scenic, or historical value.” Though not all wilderness areas contain these features, where they do exist, they must be preserved as a component of wilderness character. Where features of scenic value exist as a part of wilderness character, they can be degraded by the loss of visibility caused by air pollution.

Air Quality and the Clean Air Act

Federal land management agencies have a responsibility to protect air quality and resources in wilderness areas that might be adversely affected by air pollution. This responsibility is conferred by the Wilderness Act, with regulatory tools to achieve those goals established under the Clean Air Act. Fulfilling this responsibility requires an active role in air quality management. Engaging with other federal agencies, states, industry, and the public is important for advancing emission control or reduction strategies affecting wilderness areas. Wilderness managers have a critical role in inventorying and defining the wilderness values sensitive to air quality (these resources are called Air Quality Related Values), monitoring those resources, complying with CAA requirements, and engaging in emission control or reduction strategies through state or federal regulatory processes.

Under the CAA, there are 139 Class I wilderness areas which receive the greatest air quality protection. All other wilderness areas are managed as Class II which may receive lesser protection. However, all wilderness areas receive protection to at least the National Ambient Air Quality Standards (NAAQS), and any diminishment of air quality (in those places exceeding the NAAQS) is limited by the CAA program to prevent significant deterioration of air quality. This program emphasizes preservation, protection, and enhancement of the air quality in wilderness areas.

Though Class I areas receive the greatest protection, there are many Class II wilderness areas that are contiguous to, or very near Class I wilderness areas, and will consequently receive a benefit from their Class I neighbor. For example, the NPS’s Buffalo National River Wilderness is a Class II wilderness contiguous to the FS’s Upper Buffalo Wilderness, a Class I wilderness. Protection of the Upper Buffalo Wilderness air quality positively benefits the Buffalo National River Wilderness as well. Air quality issues typically extend beyond wilderness boundaries and agencies should collaborate on air quality protection to provide for its best possible protection. The Senate Report on the 1977 CAA stated that “the Federal Land Manager should assume an aggressive role in protecting the air quality values of land areas under his jurisdiction.”

Using This Toolbox

This toolbox will help wilderness managers understand:

  • The Legal framework for air quality management in Wilderness
  • Agency policies regarding air quality in Wilderness
  • The air pollutants of concern for wilderness areas and how they impact wilderness character
  • What natural resources in Wilderness are sensitive to air pollution
  • Management actions to take in protecting wilderness character
  • Monitoring resources
  • How do you determine the status of air quality in your wilderness area?
  • What is the legal framework for managing air quality in your wilderness area & what can you do about air quality?


Protecting Wilderness Air Quality

Agency Policy


Case Studies

Air Quality Issues Originating within Wilderness

Fire Management


For many visitors, a campfire is beloved part of a wilderness experience.  A campfire is scarcely going to impact air quality in the wilderness as a whole, but consider the impact to air quality for the visitor immediately adjacent to the fire.

Too many visitors see their campfire as a quick and convenient way to eliminate their trash, so it does not have to packed it out.  What becomes of that trash?  Most of it remains as lumps or globs of trash in a campfire ring for the next visitor to encounter; some of it is volatized and is inhaled as air pollution by those sitting around the campfire.  In fact, the next person to use the campfire ring will also get a dose of contaminates as those remaining partially burned globs are re-kindled. 

Visitors need to know that burning foil, plastic, and styrofoam releases acidic gasses, heavy metals, particulates, and toxic chemicals such as dioxin, benzyne, cadmium, and styrene.  Exposure to these toxins may cause developmental problems in children and can increase the risk of developing cancer.

Even burning paper has its problems.  Many papers are treated with plastic and include inks, both of which can emit toxic chemicals when burned.  Burning paper, including clean paper, is simply a bad first step which often escalates to throwing in more problematic trash as well.

The best practice:  If you pack it in, pack it out.