In a study published in the journal Science, researchers found that a brown pollution cloud over south Asia and the Indian Ocean is largely the result of burning wood and dung for cooking and heating. (scientificamerican.com)
He says that the «key point is that the urban pollution cloud comprises predominantly small acidic particles... which penetrate indoors and persist for long periods in air, whereas industrial dust clouds consist mainly of much larger particles». (newscientist.com)
In Hannah's game, which is now available for free on the Kodu Game Lab site, a player must solve puzzles and collect coins in order to remove soot from trees, zap pollution clouds to clean the air, and convince friends to plant more trees, all in an effort to save the environment. (dotearth.blogs.nytimes.com)