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Inhalable coarse particles —form of the 24-hour standard <br />• An area will meet the 24-hour PM10 standard when the 150µg/m3 level is not exceeded <br />more than once per year on average over a three year period. This is the same form as the <br />current 24-hour standard. <br />SOURCES OF PARTICLE POLLUTION <br />Fine particles <br />• Fine particles can be emitted directly, such as in smoke from a fire, or they can form from <br />chemical reactions of gases such as sulfur dioxide, nitrogen dioxide and some organic <br />gases. <br />• Sources of fine particle pollution (or the gases that contribute to fine particle formation) <br />include power plants, gasoline and diesel engines, wood combustion, high-temperature <br />industrial processes such as smelters and steel mills, and forest fires. <br />Coarse particles <br />• Coarse particles can be generally divided into rural, natural crustal material such as dust <br />and urban particles such as road dust kicked up by traffic (called resuspended dust), <br />construction and demolition, industries; and biological sources. <br />PARTICLE POLLUTION AND PUBLIC HEALTH <br />Thousands of new scientific studies on particulate matter have been published and peer- <br />reviewed since EPA last reviewed the standards in 1997, and before the "cutoff date" for <br />inclusion in the "criteria document" of studies for this review. These include several <br />studies used in the 1997 review that have been extended, and the data reanalyzed. <br />The majority of the studies assessed for the current review were published prior to 2003. <br />To ensure that the EPA Administrator was fully aware of new science before making a <br />final decision on the standards, EPA conducted a survey and provisional assessment of <br />relevant new studies. The Agency did not rely on these studies in making its decision on <br />the standards, however, because they have not been through as rigorous a level of review <br />as the science on which the Agency based its December 2005 proposal. EPA will <br />consider these studies in its next review. <br />Exposure to fine particle pollution <br />• Health effects associated with short-term exposure to fine particles (PM2.5) include: <br />o Premature death in people with heart and lung disease <br />o Non-fatal heart attacks <br />o Increased hospital admissions, emergency room visits and doctor's visits for <br />respiratory diseases <br />o Increased hospital admission and ER visits for cardiovascular diseases <br />o Increased respiratory symptoms such as coughing, wheezing and shortness of breath <br />o Lung function changes, especially in children and people with lung diseases such as <br />asthma. <br />o Changes in heart rate variability <br />o Irregular heartbeat <br />0 <br />