Table 1

Air pollution levels in the PAARC cities in 1974–76 and 1990–97

Cities	Areas	Evaluation of the representativeness (1974–76)		1974–76 (means levels in μg/m³)					1978–81	1990–97 (median levels in μg/m³) for all the city
Cities	Areas	Good	Heavy traffic	BS	SO₂	SO₂–AM	NO₂	NO/NO₂ >3	BS	BS	SO₂*	NO₂
SO₂*: for Bordeaux, results with the acidimetric method were presented.
NA, non-available data.
Bordeaux	Area 1	Yes	No	31	33	42	21	No	20.0
	Area 2	Yes	No	31	27	37	17	No	19.9
	Area 3	No	Yes	105	52	69	42	Yes	72.7	13.0	8.5	NA
	Area 4	Yes	No	67	47	47	32	No	43.2
Lille	Area 1	Yes	No	52	58	71	27	No
	Area 2	Yes	No	61	46	66	22	No
	Area 3	NA	No	50	17	85	19	No	NA	14.4	19.3	33.8
	Area 4	NA	No	28	21	36	19	No
Lyon	Area 1	Yes	No	77	63	88	24	No
	Area 2	Yes	No	57	72	100	14	No
	Area 3	Yes	No	39	45	56	12	No	NA	NA	14.7	47.1
	Area 4	Yes	No	60	80	94	23	No
Mantes	Area 1	Yes	No	40	37	55	26	No
	Area 2	Yes	No	35	40	49	22	No	NA	NA	NA	NA
Marseille	Area 1	No	Yes	46	35	60	13	No
	Area 2	No	Yes	141	55	105	34	Yes
	Area 3	Yes	No	152	85	120	35	Yes	NA	14.0	14.0	32.0
	Area 4	Yes	No	44	36	48	13	No
Rouen	Area 1	Yes	No	21	34	64	18	No
	Area 2	NA	No	36	32	127	23	No	NA	9.8	23.4	30.7
	Area 3	Yes	No	18	73	109	19	No
Toulouse	Area 1	No	Yes	111	25	32	61	Yes
	Area 2	Yes	No	85	23	34	42	Yes	NA	NA	10.0	28.3
	Area 3	No	Yes	91	22	13	40	Yes