Some Air Quality Facts in the Smokies
- Great Smoky Mountains NP receives more nitrogen and sulfur from the air
than any other monitored site in North America.
- The average acidity (pH) of rainfall in the park is 4.5, 5-10 times more
acidic than normal (5.6). Clouds with acidity as low as 2.0 pH bathe the high
elevation forests during part of the growing season.
- As a result of air pollution, high elevation streams in the park are so
acidified that the health of ecosystem is in jeopardy.
- Ozone symptoms are worse at high elevations since bad air tends to get trapped
by mountain peaks, this phenomenon is called an inversion.
- Average visibility in the park is now 25 miles compared to 93 miles in natural
conditions. In the summer months, the average drops to just 9 miles. During
severe haze episodes, visibility is less than one mile.