The WHO presented a new global guidelines later this year, these guidelines related to particulate matter concentrations (PM2.5, PM10) along with nitrogen dioxide, ozone, sulfur dioxide and carbon monoxid
According new guidelines the levels AQG:
The recommendation is an annual PM2.5 AQG level of 5 μg/m3
Recommended short-term (24-hour) AQG level PM2.5 = 15 μg/m3
The recommendation is an annual PM10 AQG level of 15 μg/m3 (This
is based on an evaluation of the studies on the long-term effects of
PM10 on mortality only, without taking into consideration that a large
proportion of PM10 is made up of PM2.5)
The recommendation is a short-term (24-hour) PM10 AQG level of 45 μg/m3
Conversion factors for ozone: at 20 °C and 1013 hPa, 1 part per million(ppm) = 1.9957 mg/m3 and 1 mg/m3 = 0.5011 ppm
The recommendation is a peak season ozone (O3) AQG level of 60 μg/m3 (the average of daily maximum 8-hour mean ozone concentrations)
The recommendation is an annual nitrogen dioxide (NO2) AQG level of 10 μg/m3.
The recommendation is a short-term (24-hour) sulfur dioxide (SO2) AQG level of 40 μg/m3
The recommendation is a short-term (24-hour) carbon monoxide (CO) AQG level of 4 mg/m3
The source is: https://apps.who.int/iris/handle/10665/345329
