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Air Pollution Impacts

Hawai'i Volcanoes National Park

Natural and scenic resources in Hawai'i Volcanoes National Park (NP) are susceptible to the harmful effects of air pollution. The Kilauea Volcano is a significant source of air pollution in the park, emitting particulate matter and sulfur dioxide that can harm human health and impact scenic resources. Human-caused air pollution also affects the park. Click on the tabs below to learn more about air pollutants and their effect on natural and scenic resources at Hawai'i Volcanoes NP.

  • Sulfur & Nitrogen
  • Visibility
  • Ozone
Photograph of ranger at Halema‘uma‘u Crater on the summit of Kīlauea volcano at Hawaii Vollcanoes NP, HI.
The Kilauea Volcano (pictured here) is the main contributor of sulfur dioxide at Hawai’i Volcanoes NP, HI.

Nitrogen (N) and sulfur (S) compounds deposited from air pollution can harm vegetation, soils, and surface waters throughout Hawai'i Volcanoes NP. Nitrogen acts as a fertilizer; disrupting soil nutrient cycling, altering plant communities, and contributing to overenrichment and eutrophication in surface waters. Ecosystem sensitivity to nutrient N enrichment at Hawai'i Volcanoes NP relative to other national parks is high (Sullivan et al. 2011a; Sullivan et al. 2011b [pdf, 4.4 MB]). Lowland grasslands and meadow communities at the park may be particularly vulnerable to changes caused by nitrogen deposition. Invasive grasses tend to thrive in areas with high nitrogen deposition, displacing native vegetation adapted to low nitrogen conditions (e.g., Brooks 2003, Schwinning et al. 2005). Non-native plants and wildlife introduced by humans severely threatens native flora and fauna at the park.

N, together with S, can also acidify surface waters and soils, precluding the survival of sensitive species and inhibiting natural processes. The ecosystem sensitivity to acidification from N and S at Hawai’i Volcanoes NP relative to other national parks is high (Sullivan et al. 2011c; Sullivan et al. 2011d [pdf, 1.8 MB])

The park’s streams and ponds may be particularly sensitive to sulfur compounds emitted from the Kilauea Volcano. Previous records indicate that the wet deposition of sulfur is very high at the park, as might be expected because of Kilauea’s sulfur dioxide emissions.

Sulfur Dioxide at Hawai'i Volcanoes NP and Public Health Concerns

The primary source of sulfur dioxide emissions at Hawai'i Volcanoes National Park (NP) is natural volcanic activity. The park is a unique unit within the national park system because it periodically has extremely high concentrations of sulfur dioxide - far higher than any other national park or even most urban areas. Concentrations of sulfur dioxide in the park's air often exceed the National Ambient Air Quality Standards set by the U.S. Environmental Protection Agency to protect public health. Power plants, industries and automobiles also emit sulfur dioxides (and nitrogen oxides).

Sulfur dioxide (SO2) irritates the skin and mucous membranes of the eyes, nose, throat, and lungs. High concentrations of SO2 can cause inflammation and irritation of the respiratory system, particularly during heavy physical activity. The resulting symptoms may include pain when taking a deep breath, coughing, throat irritation, and breathing difficulties. High concentrations of SO2 can affect lung function, worsen asthma attacks, and aggravate existing heart disease in sensitive groups. Given these concerns, a SO2 Advisory System was established at Hawai’i Volcanoes NP. more »






Visitors come to Hawai'i Volcanoes NP to experience the heartbeat of a volcanic landscape. The landscape ranges over varied ecosystems with many unique plant and wildlife species, from Mauna Loa's vast alpine crater at 13,667 feet in elevation down to the wind-swept shores of the Pacific Ocean. The air is generally very clean in the park so even a very small amount of particle pollution can cause a noticeable haze. If Kilauea is active, park vistas are obscured by volcanic smog or "vog", and particulate pollution. While the volcano dominates total emissions, local human-caused sources like power generating stations and automobiles can also contribute to haze and visibility impairment. Additionally, organic compounds, soot, dust, and marine aerosols reduce visibility.

Visibility effects at Hawai'i Volcanoes NP include:

  • Reduced visibility, at times, due to human-caused haze from fine particles of air pollution;
  • Reduction of the average natural visual range from about 150 miles (without pollution) to about 110 miles because of pollution at the park;
  • Reduction of the visual range to below 35 miles on high pollution days.

(Source: IMPROVE 2013)

Images of good and poor visibility at Hawaii Volcanoes National Park, Hawaii
Air pollutants can affect visibility at Hawai'i Volcanoes NP, Hawai'i (clear to hazy from left to right)

Fine particles at Hawai'i Volcanoes NP and Public Health Concerns

Concentrations of fine particles in the park's air sometimes exceed the National Ambient Air Quality Standards set by the U.S. Environmental Protection Agency to protect public health. This is largely a result of Kilauea eruptions. Fine particles, defined as those smaller than 2.5 microns, originate from either direct emissions from a source, such as volcanoes, power plants and fires, or are formed downwind from sources by gases and aerosols that react in the atmosphere.

Because of their small size, fine particles can get deep into the lungs and cause serious health problems. Numerous scientific studies have linked particle pollution exposure to irritation of the airways, coughing, difficulty breathing, aggravated asthma, chronic bronchitis, heart attacks, and premature death in people with heart or lung disease.

Additional Information:

  • Explore scenic vistas through a live webcam at Hawai'i Volcanoes National Park!
  • View of Halema´uma´u Crater more »
  • Current Sulfur Dioxide and Fine Particulate Conditions more »

Get Visibility Data »


Scenic photograph of Hawai'i Volcanoes NP.
Elevated ozone levels can harm human health and damage sensitive plants, as well as contribute to smog.

Naturally-occurring ozone in the upper atmosphere absorbs the sun's harmful ultraviolet rays and helps to protect all life on earth. However, in the lower atmosphere, ozone is an air pollutant, forming when nitrogen oxides from vehicles, power plants, and other sources combine with volatile organic compounds from gasoline, solvents, and vegetation in the presence of sunlight. In addition to causing respiratory problems in people, ozone can injure plants. Ozone enters leaves through pores (stomata), where it can kill plant tissues, causing visible injury, or reduce photosynthesis, growth, and reproduction.

A number of ozone-sensitive plant species occur in the park (e.g., Liquidambar styraciflua [Sweetgum], Pinus radiata [Monterey pine], Sambucus mexicana [Mexican elder]), however these non-native species are rare (Kohut 2004, [pdf, 87.8 KB]). No information is available on ozone impacts to native species. Past monitoring found relatively low levels of ozone in the park that would be unlikely to cause ozone injury to plants. Search the list of ozone-sensitive plant species (pdf, 184 KB) found at each national park.


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Studies and Monitoring icon

Studies and monitoring help the NPS understand the environmental impacts of air pollution. Access air quality data and see what is happening with Studies and Monitoring at Hawai'i Volcanoes NP.

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Last Updated: December 30, 2016