Pollen concentrations for Saturday will be falling in the low range. This decrease is due to falling temperatures, rising relative humidity and weaker winds.
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 »