Emission factors are developed from separate facilities within an industry category, so they represent typical values for an industry, but do not necessarily represent a specific source. SCCs vary in the amount of detail. For some sources, there are SCCs for individual release points within the process. Criteria pollutants are carbon monoxide, lead, nitrogen oxides, ozone, particulate matter within aerodynamic diameter less than or equal to 10 micrometers, and sulfur oxides. 10 Particulate matter with an aerodynamic diameter less than or equal to 10 micrometers is a measure of small solid matter suspended in the atmosphere.
Small particles can penetrate deeply into the lung where they can cause respiratory problems.
Emissions of PM 10 are significant from fugitive dust, power plants, commercial boilers, metallurgical industries, mineral industries, forest and residential fires, and motor vehicles. Exposures to PM-2.5 affects the most sensitive individuals in the population, including young children, the elderly and those with asthma or other chronic respiratory conditions. PM-2.5 consists of directly emitted fine particles, condensable fine particles and those formed as secondary pollutants through chemical reaction in the atmosphere. Any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions.