Air quality

Table 1. Mean and maximum (in parenthesis) values of air pollution in  Riga, measured by DOAS stations

Pollution, in µg/m3	The place and time of measurements (streets)
	Kr.Valdemara iela   (Centre)1996	13. janvara iela  (Old City) 1997	Nometnu iela (Agenskalns) 1998	Slokas iela (Imanta region) 1998	Tvaika iela (Sarkandaugava) 1999	11. Novembra krastmala         (Old City) 2000
SO2 (mean winter)	36.8 1996/97	17.2 1997/98	23.2 1998/99	18.1 1998/99	10.8 1999/00	14.3 summer 2000
NO2 (mean annual or  measuring period)	60.2	43.2	29.5	17.6	24.8	57.7 summer 2000
O3 (mean and maximal 24 h)	42.7 94.5	47.3 85.1	40.7 86.4	56.8 92	56.2 87.9	94 116.3 summer 2000
Benzene (mean and maximal 24 h)	34.4 75.5	16.4 36.7	22.2 55.8	19.5 41.8	16.6 48.1	41.7 49 summer 2000
Toluene (mean and maximal 24 h)	81.9 229	45.1 192	62.9 306	89.2 151	34.2 185	28.5 35 summer 2000
Formaldehyde (mean and maximal 24 h)	13.1 25	7.9 18.7	7.1 29.9	7.8 16.8	8.2 13.5	-

Source: Riga City towards Sustainability