 (CC) Photo: Tom Bougher A point source of Industrial air pollution. |
 (CC) Photo: Mila Zinkova Sulfur dioxide emissions from the Halemaumau vent in in Kīlauea, Hawaii |
 (CC) Photo: Erik Charlton Wildfire near Santa Barbara, California. |
 (PD) Photo: National Park Service Point sources of Industrial air pollution. |
 © Photo: Kenn Kiser A point source of industrial air pollution. |
 (PD) Photo: U.S. Agency for International Development A point source of industrial air pollution. |
 (PD) Photo: U.S. EPA Point sources of industrial air pollution |
 (PD) Photo: NOAA George E. Marsh Album Dust storm approaching Stratford, Texas in 1935 |
 (CC) Photo: Owen Byrne Air pollution sources in Dartmouth, Nova Scotia, Canada. |
 (CC) Photo: Hrönn Traustadóttir Iceland's Eyjafjallajökull Glacier volcano eruption in 2010 |
 (PD) Photo: Mircea Madau Lightning over Oradea, Romania in August 2005 |
 (PD) Photo: U.S. EPA 1999 Dust storm in Phoenix, Arizona |
