Concentration of pollen grains in the air for Saturday will be greater than today's levels in the high range. The cause for the rising pollen levels is drier air.
Smog Threatens Visitors to U.S. National Parks: Report
FRIDAY, July 31, 2015 (HealthDay News) -- Air pollution afflicts many national parks across the United States, a new study suggests.
Air quality in some of the parks is as bad or worse than in some major cities because of pollution from sources such as coal-fired power stations, the National Parks Conservation Association ... Full Article »