Air pollution

Air quality limit values for the protection of human health of 8 main polluting agents

Polluting Substance	Legislation guidelines of the Republic of Latvia (are in force from 01.01.2000)
	MPK 24 h mg/m3	MPK1 h mg/m3	MPKyear mg/m3
SO2 Sulphur dioxide	125 no more than 3 times in year; will come into effect from 2005	500 no more than 24 times in year; gradually reduce to 350 in 2005	20 (in winter), will come into effect from 2003
NO2 Nitrogen dioxide	-	300 no more than 18 times in year; reduce to 200 in 2010	58 in 2001and must be reduced to 40 in 2010
NO2 + NO Nitrogen oxides	-	-	30 will come into effect from 2003
O3 Ozone	65	200; 110 - value for 8-hour conc.	-
Benzene	100	500 (30 min)	<10 (annual limit established by EC Directive 2000/69/EC)
Toluene	600	600 (30 min)	-
Formaldehyde	3	35   (30 min)	-
p, m-xylene	200	200 (30 min)	-
PM10particles	75 no more then 35 times in year; must be reduced to 50 in 2005	-	58 in 2001; must be reduced to 40 in 2005
PM2.5particles	60 no more then 14 times in year; must be reduced to 40 in 2005	-	28 in 2001; must be reduced to 20 in 2005.