Titre The WHO (World Health Organization)

WHO (World Health Organization) recommended exposure levels (concentrations and durations) below which there was no evidence of adverse effects on human health and vegetation.

World health organisation air quality guideline according to the Guideline for air quality, WHO, Geneva 2000 ( pdf - 798 ko)and since 2006 for the particulate matter, ozone, nitrogen dioxide and sulphur dioxide: WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide, summary of risk assessment, global update 2005 . ( pdf)

All values are in microgram per cubic metre.

Exposure
Polluants 10 min 15 min 30 min 1 hour 8
hours		 24
hours		 week year UR Life (µg/m³)-1
Nitrogen dioxide
(NO2)		 200 40
Nitrogen monoxide
(NO) 		No Guidelines available
Ozone
(O3)		 100
Sulfur dioxide
(SO2)		 500 20
Lead
(Pb)		 0,5
Particles with a diameter of 10 micrometers or less
(PM10)		 50
not to be exceeded more than  3 days per year		 20
Particles with a diameter of 2.5 micrometers or less
(PM2,5)		 25
not to be exceeded more than  3 days per year 		10
Black Carbon
(Fumées noires)		 No Guidelines available
Carbon monoxide
(CO)		 100 000 60 000 30 000 10 000
Benzene
(C6H6)		 6x10-6
Toluene
(C7H8)		 260
Xylene

 4 800
Ethylbenzene
(C8H10)		 22 000
Benzo(a)anthracene

 1,2x10-4
à 13x10-4
Benzo(a)pyrene

 8,7x10-2
Benzo(b)fluoranthene

 0,87x10-2
 à 1,2x10-2
Benzo(k)fluoranthene

 8,7x10-4
à 87x10-4
Fluoranthene

 8,7x10-5
 à 87x10-5
Indéno(1,2,3-c,d)pyrene
 5,8x10-3 à 20,2x10-3
Dibenzo(ah)anthracene

 7,7x10-2 à 43,5x10-2
Acetaldehyde

 1,5x10-7
à 9x10-7
Polluants 10 min 15 min 30 min 1 hour 8
hours		 24
hours		 week year UR Life (µg/m³)-1
UR : Unit risk (UR) estimated for an air pollutant is defined as “the additional lifetime cancer risk occurring in a hypothetical population in which all individuals are exposed continuously from birth throughout their lifetimes to a concentration of 1 μg/m3 of the agent in the air they breathe”.