Coarse Particulate Matter (PM10) is defined as particulate matter with a diameter of less than 10 micrometers. Geologic and chemical weathering of rocks, pollination of plants, and combustion of fuel are some of the ways that PM10 can be created. Particulate matter can contribute to increased weathering of geologic and anthropogenic (human-made) materials, thereby creating more particulate matter.
As of December 17, 2006, the U.S. EPA revoked the annual PM10 standards since there was not predominant evidence showing adverse health effects related to long term exposure. Since December 31, 2004 we no longer monitor for PM10 but the monitors have been converted to measure PM2.5 at two sites: downtown Akron and East High School in Akron.
More in depth information about particulate matter is available through the EPA including basic information, health and welfare, standards, designations, implementation, regulatory actions, research, trends, sources, and other resources.