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Particulates or atmospheric particulate matter (see below for other names) are microscopic particles of solid or liquid matter suspended in the air.The term aerosol refers to the particulate/air mixture, as opposed to the particulate matter alone, [1] though it is sometimes defined as a subset of aerosol terminology. [2]
In European countries, air quality at or above 10 micrograms per cubic meter of air (μg/m 3) for PM 2.5 increases the all-causes daily mortality rate by 0.2-0.6% and the cardiopulmonary mortality rate by 6-13%. [35] Worldwide, PM 10 concentrations of 70 μg/m 3 and PM 2.5 concentrations of 35 μg/m 3 have been shown to increase long-term ...
Particulate matter (PM) in the atmospheric air or in any other gas cannot be expressed in terms of ppmv, ppbv, volume percent or mole percent. PM is most usually (but not always) expressed as mg/m 3 of air or other gas at a specified temperature and pressure.
Particulate systems are characterized by the birth and death of particles. For example, consider precipitation process (formation of solid from liquid solution) which has the subprocesses nucleation , agglomeration , breakage, etc., that result in the increase or decrease of the number of particles of a particular radius (assuming formation of ...
As another example, a regulation might limit the concentration of particulate matter to 0.1 grain per standard cubic foot (i.e., scf) of dry exhaust gas corrected to 12 volume percent CO 2. Environmental agencies in the USA often denote a standard cubic foot of dry gas as "dscf" or as "scfd".
Outdoor particulate pollution is the largest cause of death (4.7 million), followed by indoor air pollution (3.1 million) and ozone (0.5 million). [5] The World Bank has estimated that welfare losses (premature deaths) and productivity losses (lost labour) caused by air pollution cost the world economy over $8 trillion per year.
Inert particulate matter can be disturbed and entrained into the smoke. Of particular concern are particles of asbestos . Deposited hot particles of radioactive fallout and bioaccumulated radioisotopes can be reintroduced into the atmosphere by wildfires and forest fires ; this is a concern in e.g. the Zone of alienation containing contaminants ...
The rate of phytoplankton breakdown can be represented using this equation: = In this equation, G(t) is the amount of particulate organic carbon (POC) overall at a given time, t. G(0) is the concentration of POC before breakdown takes place. k is a rate constant in year-1, and t is time in years.