tailieunhanh - Iowa Air Pollution: Take a deep breath

The USC Children’s Health Study suggests that children with asthma living in a community with high particle concentrations may have suppressed lung growth. After children moved into cleaner cities their lung growth returned to the normal rate, but they did not recover the lost potential growth, according to John Peters, the study's principle investigator. It is difficult to positively assign a quantitative risk associated with particulate matter because nearly all studies of its health effects find other pollutants present that may account for some of the effects. Part of the problem is due to the nature. | Iowa Air Pollution Iowa Association of Naturalists Iowa Environmental Issues Series __ Iowa Air Pollution Iowa Air Pollution Take a deep breath When we think of Iowa we think of a rural state with clean clear air. When we take a deep breath we take comfort in knowing the air is clean and healthful. We imagine ourselves to be immune from the choking filth of big industrial cities. Although headlines may tell stories of polluted water and eroding farm land we are confident that Iowa s air is clean. However in some places in Iowa air pollution is a problem. Iowa Association of Naturalists 1 Iowa Air Pollution Something in the air A variety of substances are floating around in Iowa s air. Many of the more harmful substances are created through human activities. These pollutants are classified according to their makeup and their effects on people. Particulate pollutants consist of fine particles of dust soot or other materials carried in the air. Six chemical pollutants consisting of various chemical substances have been closely monitored throughout recent decades. These chemicals may be directly harmful to people or may become harmful when they react with other chemicals in the atmosphere. Some particulate and chemical pollutants are deadly. These hazardous air pollutants may be radioactive carcinogenic or have other toxic effects. Monitoring Iowa pollution Air pollutants are monitored and regulated by the Iowa Department of Natural Resources DNR . The federal Clean Air Act of 1990 requires states and businesses to maintain levels of known pollutants below National Ambient Air Quality Standards NAAQS . Businesses and utilities must keep their emissions below the amounts allowed by the State of Iowa and the Clean Air Act. If they are not able to meet these standards major emitters must use the lowest achievable rate technology to reduce emissions. Any increase in emissions must be