Parameters Measured

PM-2.5 (Local Conditions) Acceptable

PM-2.5 (Local Conditions) Acceptable is measured in micrograms per cubic meter (local conditions).

Fine particulates (PM-2.5) are generally emitted from activities such as industrial and residential combustion and from vehicle exhaust. Fine particles are also formed in the atmosphere when gases such as sulfur dioxide, nitrogen oxides, and volatile organic compounds, emitted by combustion activities, are transformed by chemical reactions in the air. Large-scale agricultural burning or sand storms can produce huge volumes of fine particulates. PM-2.5 data is the near real-time measurement of particulate matter 2.5 microns or less in size from the surrounding air. This measurement is made at local conditions, and is not corrected for temperature or pressure.