High winds in Mason City Wednesday blew up some dirty air that’ve created concern for the Department of Natural Resources. D-N-R air information specialist Brian Button says the wind apparently blew up dust from cement plants, and led to unhealthy air quality levels. Button says the cement plants have been working to control emissions. He says they’re trying to control emissions form vents and smoke stacks as well as piles of material. Button says they don’t know exactly where the emissions came from. Button says the last unhealthy air was recorded in Mason City back in February of 2002. He says the latest event raises a concern. He says they deal with a three-year standard, and if there’s another event, it would be the third in three years, putting the area on the cusp of not meeting healthy air standards. Button says the state overall has had few problems with dirty air. He says the conditions have been good this winter and most of last summer, with few problems with smog. Button says we’re meeting federal air quality standards, and our air is a lot cleaner than a lot of states. Button says you can view current air quality conditions in Iowa and nationally at www.iowacleanair.com.