Particulate matter (PM) is fine mineral, metal, soot, smoke, and dust particles suspended in the air. For health reasons, we are most concerned with inhalable particulate matter less than 10 microns in diameter (PM10), and less than 2.5 microns in diameter (PM2.5). Particles of these sizes can permanently lodge in the deepest and most sensitive areas of the lung, and can aggravate many respiratory illnesses including asthma, bronchitis, and emphysema.
For more information on particulate matter, visit the EPA website.
The federal Environmental Protection Agency (EPA) and the state have set standards for PM10. The EPA recently set a new standard for PM 2.5. APCD currently receives data from equipment that monitors PM 2.5 and PM10 levels around the county. For more information on the PM standards, see: http://www3.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html.
Sources of PM10 and PM 2.5 in the county include mineral quarries, grading, demolition, agricultural tilling, road dust, and vehicle exhaust. Sea salt and wind blown dust are examples of naturally occurring particulate matter. Santa Barbara County air meets the federal PM standards, and exceeds the state PM10 standard.
The figure below shows the maximum recorded concentration of PM10 in the County since 1998.