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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 mortality by 15%. [29] More so, approximately 4.2 million of all premature deaths observed in 2016 occurred due to airborne particulate pollution, 91% of which occurred in countries with low to middle socioeconomic status.
Air pollution measurement is the process of collecting and measuring the components of air pollution, notably gases and particulates. The earliest devices used to measure pollution include rain gauges (in studies of acid rain), Ringelmann charts for measuring smoke, and simple soot and dust collectors known as deposit gauges. [1]
SO 2, NO 2 and PM 10 concentration are measured as average per day. CO and O 3 are more harmful and are measured as average per hour. The final AQI value is calculated per day. The scale for each pollutant is non-linear, as is the final AQI score. Thus an AQI of 100 does not mean twice the pollution of AQI at 50, nor does it mean twice as harmful.
During haze episodes, PM 2.5 is the most significant pollutant. [8] The PSI is reported as a number on a scale of 0 to 500. The index figures enable the public to determine whether the air pollution levels in a particular location are good, unhealthy, hazardous or worse.
PM can be different sizes, such as PM 2.5 which are tiny particles of 2.5 microns in width or smaller, compared with PM 10 which are classified as 10 microns in diameter or less. A study in California found that increased exposure to PM 2.5 led to decreased sperm motility and increased abnormal morphology.
While an AQI of 50 from day 1 to 182 and AQI of 100 from day 183 to 365 does provide an annual average of 75, it does not mean the pollution is acceptable even if the benchmark of 100 is deemed safe. Because the benchmark is a 24-hour target, and the annual average must match the annual target, it is entirely possible to have safe air every day ...
Maternal PM 2.5 exposure during pregnancy is also associated with high blood pressure in children. [218] Inhalation of PM 2.5 – PM 10 is associated with elevated risk of adverse pregnancy outcomes, such as low birth weight. [219] Exposure to PM 2.5 has been associated with greater reductions in birth weight than exposure to PM 10. [220]
To discriminate between particle of different sizes (e. g., between PM 10 and PM 2.5), some preliminary separation could be accomplished, for example, by cyclone battery. A similar method exists, where instead of beta particle flow an X-ray Fluorescence Spectroscopic monitoring is applied on the either side of air flow contact with the ribbon.