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Exposure to particulate matter of less than 2.5 micrometers in diameter led to significant changes in ROS levels, indicating that particulate matter exposure was a causative agent of oxidative stress in Tigriopus japonicus. [42] In addition to aquatic invertebrates, negative effects of particulate matter have been noted in mammals as well.
The guidelines stipulate that PM 2.5 should not exceed 5 μg/m 3 annual mean, or 15 μg/m 3 24-hour mean; and that PM 10 should not exceed 15 μg/m 3 annual mean, or 45 μg/m 3 24-hour mean. [2] For ozone (O 3 ), the guidelines suggest values no higher than 100 μg/m 3 for an 8-hour mean and 60 μg/m 3 peak season mean. [ 2 ]
PM 2.5, 24 hour 0 0 0 0 0 0 0 0 0 0 0 50 50 150 40 100 50 2 5 160 100 35 100 150 500 80 200 150 4 10 200 160 75 150 475 650 180 700 250 14 35 300 215 115 200 800 800 280 1200 350 24 60 400 265 150 300 1600 (2) 565 2340 420 36 90 800 800 250 400 2100 (2) 750 3090 500 48 120 1000 (3) 350 500 2620 (2) 940 3840 600 60 150 1200 (3) 500
A new study out today names Columbus as the most polluted major city in the United States for 2023. But is it really? EPA and other findings differ.
40 CFR 50.5: Particulate matter (PM 10) Primary and Secondary 150 μg/m 3: 24-hour Not to be exceeded more than once per year on average over 3 years 40 CFR 50.6: Fine particulate matter (PM 2.5) Primary 9.0 μg/m 3 (12 μg/m 3 prior to May 6, 2024) [25] annual Annual mean, averaged over 3 years 40 CFR 50.18: Secondary 15 μg/m 3: annual
For example, in the United States, people with a high school degree had 6.2% higher estimated exposure to PM 2.5 compared to those with a college degree. In addition to PM 2.5, people with a high school degree or lower are estimated to have at least 10% more exposure to Al, Ca, Cl, EC, SI, TI, V, and Zn when compared to people with a college ...
This list contains the top 500 cities by PM2.5 annual mean concentration measurement as documented by the World Health Organization covering the period from 2010 to 2022. The January 2024 version of the WHO database contains results of ambient (outdoor) air pollution monitoring from almost 5,390 towns and cities in 63 countries.
PM is most usually (but not always) expressed as mg/m 3 of air or other gas at a specified temperature and pressure. For gases, volume percent = mole percent 1 volume percent = 10,000 ppmv (i.e., parts per million by volume) with a million being defined as 10 6 .