Park Air Profiles - Glacier National Park

Hidden Lake
Visitors come to Glacier NP to view active glaciers and beautiful lakes and streams.

Air quality at Glacier National Park

Most visitors expect clean air and clear views in parks. Glacier National Park (NP), Montana, boasting glacial vistas and relatively pristine surface waters, is downwind of many pollutant sources, including power plants, agricultural areas, oil and gas development, and other industry. Air pollutants blown into the park can harm natural and scenic resources such as soils, surface waters, plants, wildlife, and visibility. The National Park Service works to address air pollution effects at Glacier NP, and in parks across the U.S., through science, policy and planning, and by doing our part.

Mercury and toxics

Park visitor fishing at Quartz LakeFish consumption advisories are in effect for some lakes at Glacier NP due to fish found with levels of mercury that exceed safe human consumption thresholds.

Airborne mercury, and other toxic air contaminants, when deposited are known to harm birds, salamanders, fish and other wildlife, and cause human health concerns. These substances enter the food chain and accumulate in the tissues of organisms causing reduced reproductive success, impaired growth and development, and decreased survival.

Research findings from the Western Airborne Contaminants Assessment Project (WACAP), Rocky Mountain Regional Snowpack Chemistry Monitoring Study, Glacier National Park Fisheries Inventory and Monitoring, and other studies found airborne contaminants in fish, vegetation, snow, and lake sediments in the park (Downs and Stafford 2009; Downs et al. 2011; Hageman et al. 2006; Ingersoll et al. 2007; Krabbenhoft et al. 2002; Landers et al. 2010; Landers et al. 2008; Mast et al. 2006; Watras et al. 1995). .

The park is investigating the presence of selenium in fish (Downs et al. 2011). Growing scientific evidence suggests that selenium affects the fate of mercury in aquatic food chains and may moderate its toxicity. However, the protective effects of selenium against mercury toxicity rely on a fine balance of selenium in the diet as it can also be toxic to organisms (Peterson et al. 2009).

Mercury and toxics effects:

  • Concentrations of a combustion by-product, Polycyclic aromatic hydrocarbons (PAHs), in snow, lichen, and sediment is 3.6 to 60,000 times greater in the park’s Snyder Lake watershed than in other western and Alaskan national park watersheds; levels attributable to emissions from a local aluminum smelter. Although the smelter is now closed, PAHs deposited from its emissions persist in the park’s ecosystems (Usenko et al. 2010).
  • Levels of historic-use pesticides dieldrin and DDT in fish exceed safe consumption thresholds for human and wildlife health, and concentrations of current-use pesticides in fish are higher than in other western U.S. national parks (Ackerman et al. 2008; Landers et al. 2010; Landers et al. 2008).
  • Concentrations of mercury in fish from numerous lakes in the park exceed safe consumption thresholds for human and wildlife health (Downs and Stafford 2009; Downs et al. 2011), prompting guidelines for fish consumption (GNP 2009).
  • Mercury levels associated with tissue damage in fish kidney and spleen (Schwindt et al. 2008);
  • Male intersex fish (the presence of both male and female reproductive structures in the same fish) found in the park, a response that indicates exposure to contaminants (Schwindt et al. 2009). Follow-up research is examining the extent to which contaminants are disrupting reproductive organs in park fish.

Glacier NP has been monitoring atmospheric mercury deposition since 2003. Explore air monitoring »

Nitrogen and sulfur

Nitrogen and sulfur compounds deposited from the air may have harmful effects, including acidification. Surface waters in some park watersheds are sensitive to acidification from sulfur and nitrogen deposition. Watersheds that receive glacial runoff are less sensitive to acid deposition due to buffering minerals like calcium in the runoff (Ellis et al. 1992; Clow et al. 2002; Nanus et al. 2009; Peterson et al. 1998; Sullivan et al. 2011c; Sullivan et al. 2011d). Additionally, some plants are more sensitive to acidification than others, search for acid-sensitive plant species found at Glacier NP.

Excess nitrogen can also lead to nutrient enrichment, a process that changes nutrient cycling and alters plant communities. Healthy ecosystems can naturally buffer a certain amount of pollution, but as nitrogen accumulates, a threshold is passed where the ecosystem is harmed. “Critical load” is a term used to describe the amount of pollution above which harmful changes in sensitive ecosystems occur (Porter 2005). Nitrogen deposition exceeds the critical load for one or more park ecosystems (NPS ARD 2018). Certain vegetation communities in the park, including alpine and wetland, are at high risk of nitrogen enrichment (Bowman 2009; Sullivan et al. 2011a; Sullivan et al. 2011b). Research in the park’s Snyder and Oldman Lakes indicates that aquatic communities appear undisturbed by nitrogen deposition to that area, which suggests these lakes are phosphorus-limited (Ellis et al. 1992; Saros 2009).

Other factors such as climate change may exacerbate the effects of nitrogen deposition. Glaciers act as sinks for atmospheric pollutants, accumulating nitrogen over time. As the climate continues to warm, melting glaciers will release stored nitrogen to downstream lakes, disrupting natural nutrient cycling and changing lake ecosystems (Saros et al. 2010).

Visit the NPS air quality conditions and trends website for park-specific nitrogen and sulfur deposition information. Glacier NP has been monitoring atmospheric nitrogen and sulfur deposition since 1980. Explore air monitoring »

Ground-level ozone

Quaking Aspen trees Quaking Aspen is one of the ozone sensitive species found at Glacier NP.

At ground level, ozone is harmful to human health and the environment. Ground-level ozone does not come directly from smokestacks or vehicles, but instead is formed when other pollutants, mainly nitrogen oxides and volatile organic compounds, react in the presence of sunlight.

Over the course of a growing season, ozone can damage plant tissues making it harder for plants to produce and store food. It also weakens plants making them less resistant to disease and insect infestations. Relatively low ozone exposure levels at Glacier NP make the risk of vegetation injury to plants low (Kohut 2004). Ozone-sensitive plants in Glacier NP include Populus tremuloides (quaking aspen) and Salix scouleriana (Scouler’s willow). Search ozone-sensitive plant species found at Glacier NP.

Visit the NPS air quality conditions and trends website for park-specific ozone information. Glacier NP has been monitoring ozone since 1992. View live ozone and meteorology data, and explore air monitoring »

Visibility

Granite Park Clean, clear air is essential to appreciating the scenic vistas at Glacier NP.

Visitors come to Glacier NP to enjoy spectacular views of active glaciers and the rugged topography and stunning lakes and streams left by the colossal glaciers of the past. Park vistas are sometimes obscured by haze, reducing how well and how far people can see. Visibility reducing haze is caused by tiny particles in the air, and these particles can also affect human health. Many of the same pollutants that ultimately fall out as nitrogen and sulfur deposition contribute to this haze. Organic compounds, soot, dust, and wood smoke reduce visibility as well. Significant improvements in park visibility have been documented since the late 1980’s. Still, visibility in the park is a long way from the Clean Air Act goal of no human caused impairment.

Visibility effects:
  • Reduction of the average natural visual range from about 145 miles (without the effects of pollution) to about 95 miles because of pollution at the park;
  • Reduction of the visual range to below 50 miles on high pollution days.

Visit the NPS air quality conditions and trends website for park-specific visibility information. Glacier NP has been monitoring visibility since 1988. View live webcams and explore air monitoring »

Ackerman, L. K., Schwindt, A. R., Massey Simonich, S. L., Koch, D. C., Blett, T. F., Schreck, C. B., Kent, M. L., Landers, D. H. 2008. Atmospherically Deposited PBDEs, Pesticides, PCBs, and PAHs in Western U.S. National Park Fish: Concentrations and Consumption Guidelines. Environmental Science and Technology 42: 2334–2341.

Bowman, W. D. 2009. Critical loads of atmospheric N deposition in alpine vegetation in Rocky Mountain and Glacier National Parks. NPS Final Completion Report.

Clow, D. W., Sickman, J. O., Striegl, R. G., Krabbenhoft, D. P., Elliott, J.G., Dornblaser, M., Roth, D. A., and Campbell, D.H. 2003. Changes in the chemistry of lakes and precipitation in high-elevation national parks in the western United States, 1985–1999. Water Resour. Res. 39(6): 1171.

Clow, D. W., Striegl, R. G., Nanus, L., Mast, M. A., Campbell, D. H., Krabbenhoft, D. P. 2002. Chemistry of Selected High-Elevation Lakes in Seven National Parks in the Western United States. Water, Air, and Soil Pollution: Focus 2: 139–164.

Downs, C. C. and Stafford, C. 2009. Glacier National Park Fisheries Inventory and Monitoring Annual Report, 2008. National Park Service, Glacier National Park, West Glacier, Montana.

Downs, C. C., Stafford, C., Langner, H., and Muhlfeld, C. C. 2011. Glacier National Park Fisheries Inventory and Monitoring Bi-Annual Report, 2009–2010. National Park Service, Glacier National Park, West Glacier, Montana.

Ellis, B. K., Stanford, J. A., Craft, J. A., Chess, D. W., Gregory, G. R., and Marnell, L. F. 1992. Monitoring of water quality of selected lakes in Glacier National Park, Montana: Analysis of data collected, 1984–1990. Open File Report 129-92 in conformance with Cooperative Agreement CA 1268-0-9001, Work Order 6, National Park Service, Glacier National Park, West Glacier, Montana. Flathead Lake Biological Station, The University of Montana, Polson.

[GNP] Glacier National Park. 2009. Contaminants in Fish and the Human Health Perspective. National Park Service, Glacier National Park, West Glacier, Montana.

Hageman, K. J., Hafner, W. D., Campbell, D. H., Jaffe, D. A., Landers, D. H., Massey Simonich, S. L. 2010. Variability in Pesticide Deposition and Source Contributions to Snowpack in Western U.S. National Parks. Environmental Science and Technology 44: 4452–4458.

Ingersoll, G. P., Mast, M. A., Nanus, L., Handran, H. H., Manthorne, D. J., and Hultstrand, D. M. 2007. Rocky Mountain snowpack chemistry at selected sites, 2004: U.S. Geological Survey Open-File Report 2007-1045, 15 p. Available at http://pubs.usgs.gov/of/2007/1045/.

Kohut, R. 2004. Assessing the Risk of Foliar Injury from Ozone on Vegetation in Parks in the Rocky Mountain Network. Available at https://irma.nps.gov/DataStore/Reference/Profile/2181542.

Kohut R.J. 2007. Ozone Risk Assessment for Vital Signs Monitoring Networks, Appalachian National Scenic Trail, and Natchez Trace National Scenic Trail. NPS/NRPC/ARD/NRTR—2007/001. National Park Service. Fort Collins, Colorado. Available at https://www.nps.gov/articles/ozone-risk-assessment.htm.

Krabbenhoft, D. P., Olson, M. L., Dewild, J. F., Clow, D. W., Striegl, R. G., Dornblaser, M. M., and VanMetre, P. 2002. Mercury loading and methylmercury production and cycling in high-altitude lakes from the western United States. Water, Air, and Soil Pollution, Focus 2: 233–249.

Landers, D. H., Simonich, S. M., Jaffe, D. A., Geiser L. H., Campbell, D. H., Schwindt, A. R., Schreck, C. B., Kent, M. L., Hafner, W. D., Taylor, H. E., Hageman, K. J., Usenko, S., Ackerman, L. K., Schrlau, J. E., Rose, N. L., Blett, T. F., and Erway, M. M. 2008. The Fate, Transport, and Ecological Impacts of Airborne Contaminants in Western National Parks (USA). EPA/600/R—07/138. U.S. Environmental Protection Agency, Office of Research and Development, NHEERL, Western Ecology Division, Corvallis, Oregon. Available at https://irma.nps.gov/DataStore/Reference/Profile/660829.

Landers, D. H., Simonich, S. M., Jaffe, D. A., Geiser L. H., Campbell, D. H., Schwindt, A. R., Schreck, C. B., Kent, M. L., Hafner, W. D., Taylor, H. E., Hageman, K. J., Usenko, S., Ackerman, L. K., Schrlau, J. E., Rose, N. L., Blett, T. F., and Erway, M. M. 2010. The Western Airborne Contaminant Assessment Project (WACAP): An Interdisciplinary Evaluation of the Impacts of Airborne Contaminants in Western U.S. National Parks. Environmental Science and Technology. Vol 44: 855–859.

Mast, M. A., Foreman, W. T., and Skaates, S. V. 2006. Organochlorine compounds and current-use pesticides in snow and lake sediment in Rocky Mountain National Park, Colorado, and Glacier National Park, Montana, 2002–03. U.S. Geological Survey, SIR 2006-5119. Reston, VA. Available at https://pubs.usgs.gov/sir/2006/5119/.

Nanus, L., Williams, M. W., Campbell, D. H., Tonnessen, K. A., Blett, T., and Clow, D. W. 2009. Assessment of lake sensitivity to acidic deposition national parks of the Rocky Mountains. Ecological Applications 19(4): 961–973.

[NPS] National Park Service. 2010. Air Quality in National Parks: 2009 Annual Performance and Progress Report. Natural Resource Report NPS/NRPC/ARD/NRR—2010/266. National Park Service, Denver, Colorado. Available at https://irma.nps.gov/DataStore/Reference/Profile/2166247.

Peterson, S. A., Ralston, N. V. C., Peck, D. V., Van Sickle, J., Robertson, D. V., Spate, V. L., Morris, J. S. 2009. How might selenium moderate the toxic effects of mercury in stream fish of the western U.S.? Environ Sci Technol 43: 3919–3925.

Peterson, D. L., Sullivan, T. J., Eilers, J. M., Brace, S., Horner, D., Savig, K., and Morse, D. 1998. Assessment of air quality and air pollutant impacts in national parks of the Rocky Mountains and northern Great Plains. Report NPS/CCSOUW/NRTR—98/19. National Park Service, Air Resources Division, Denver, CO. Chapter 6: Glacier National Park. Available at https://irma.nps.gov/DataStore/Reference/Profile/11733.

Porter, E., Blett, T., Potter, D.U., Huber, C. 2005. Protecting resources on federal lands: Implications of critical loads for atmospheric deposition of nitrogen and sulfur. BioScience 55(7): 603–612. https://doi.org/10.1641/0006-3568(2005)055[0603:PROFLI]2.0.CO;2

Saros, J. E., Rose, K. C., Clow, D. W., Stephens, V. C., Nurse, A. B., Arnett, H. A., Stone, J. R., Williamson, C. E., Wolfe, A. P. 2010. Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive Nitrogen. Environmental Science and Technology 44(13): 4891–4896.

Saros, J. 2009. Inferring Critical Nitrogen Deposition Loads to Alpine Lakes of Western National Parks and Diatom Fossil Records. NPS Final Report. 13 pp.

Schwindt, A. R., Kent, M. L., Ackerman, L. K., Massey Simonich, S. L., Landers, D. H., Blett, T., Schreck, C. B. 2009. Reproductive Abnormalities in Trout from Western U.S. National Parks. Transactions of the American Fisheries Society 138: 522–531.

Schwindt, A. R., Fournie, J. W., Landers, D. H., Schreck, C. B., Kent, M. 2008. Mercury Concentrations in Salmonids from Western U.S. National Parks and Relationships with Age and Macrophage Aggregates. Environmental Science and Technology 42(4): 1365–1370.

Sullivan, T. J., McDonnell, T. C., McPherson, G. T., Mackey, S. D., Moore, D. 2011a. Evaluation of the sensitivity of inventory and monitoring national parks to nutrient enrichment effects from atmospheric nitrogen deposition: main report. Natural Resource Report NPS/NRPC/ARD/NRR—2011/313. National Park Service, Denver, Colorado. Available at https://www.nps.gov/articles/nitrogen-risk-assessment.htm

Sullivan, T. J., McDonnell, T. C., McPherson, G. T., Mackey, S. D., Moore, D. 2011b. Evaluation of the sensitivity of inventory and monitoring national parks to nutrient enrichment effects from atmospheric nitrogen deposition: Rocky Mountain Network (ROMN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/324. National Park Service, Denver, Colorado. Available at https://irma.nps.gov/DataStore/Reference/Profile/2168730.

Sullivan, T. J., McPherson, G. T., McDonnell, T. C., Mackey, S. D., Moore, D. 2011c. Evaluation of the sensitivity of inventory and monitoring national parks to acidification effects from atmospheric sulfur and nitrogen deposition: main report. Natural Resource Report NPS/NRPC/ARD/NRR—2011/349. National Park Service, Denver, Colorado. Available at https://www.nps.gov/articles/acidification-risk-assessment.htm.

Sullivan, T. J., McPherson, G. T., McDonnell, T. C., Mackey, S. D., Moore, D. 2011d. Evaluation of the sensitivity of inventory and monitoring national parks to acidification effects from atmospheric sulfur and nitrogen deposition: Rocky Mountain Network (ROMN). Natural Resource Report NPS/NRPC/ARD/NRR—2011/349. National Park Service, Denver, Colorado. Available at https://irma.nps.gov/DataStore/Reference/Profile/2170599.

Sullivan T.J. 2016. Air quality related values (AQRVs) in national parks: Effects from ozone; visibility reducing particles; and atmospheric deposition of acids, nutrients and toxics. Natural Resource Report. NPS/NRSS/ARD/NRR—2016/1196. National Park Service. Fort Collins, Colorado. Available at https://www.nps.gov/articles/aqrv-assessment.htm

Usenko, S., Massey Simonich, S. L., Hageman, K. J., Schrlau, J. E., Geiser, L., Campbell, D. H., Applyby, P. G., Landers, D. H. 2010. Sources and Deposition of Polycyclic Aromatic Hydrocarbons to Western U.S. National Parks. Environmental Science and Technology 44: 4512–4518.

Watras, C. J., Morrison, K. A., Bloom, N. S. 1995. Mercury in remote Rocky Mountain Lakes of Glacier National Park, Montana, in comparison with other temperate North American regions. Canadian Journal of Fisheries and Aquatic Sciences 52(6): 1220–1228.

Last updated: September 5, 2018