Table 7

Summary of time series studies of air pollution and daily admissions or emergency room attendance for asthma. The rows are sorted by whether the analysis was for “all year” (including across seasons) and by “summer” (warm half of the year) or “winter” (cool half of the year). Under the various age groups where a pollutant is within a parenthesis, the association was negative

Author	Reference no.	Year	Place	Ads/ ER	Season	Months	O₃	NO₂	SO₂	Particles	0–14 yrs	15–64 yrs	65+ yrs	All ages
Anderson	This paper		London	Ads	AY		+	+	+	BS	NO₂,SO₂	O₃	NO₂,BS	NO₂,SO₂,BS
Buchdahl	20	1996	London	ER	AY		+	+	+	—	O₃,SO₂	—	—	—
Dab	21	1996	Paris	Ads	AY		+	+	+	PM₁₃,BS	SO₂	O₃,NO₂	—	SO₂,NO₂
Ponka	22	1996	Helsinki	Ads	AY		+	+	+	TSP	NS	NS	SO₂	—
Romieu	923	1995	Mexico City	ER	AY	Jan–Jun	+	—	+	—	O₃,SO₂	—	—	—
Schwartz	24	1993	Seattle	ER	AY		+	—	+	PM₁₀	PM₁₀	PM₁₀	NS	—
Sunyer	14	1996	Barcelona	ER	AY		+	+	+	BS	—	O₃	—	—
Anderson	This paper		London	Ads	S	Apr–Sept	+	+	+	BS	O₃,NO₂,SO₂	O₃	NS	O₃,SO₂
Bates	25	1990	Vancouver	ER	S		+	+	+	SO₄,COH	SO₄	SO₂,SO₄	SO₄	—
Bates	26	1987	Ontario	Ads	S	July–Aug	+	+	+	SO₄,COH	NS	—	—	SO₂,O₃,SO₄
Burnett	27	1994	Ontario	Ads	S	May–Aug	+	—	—	SO₄	O₃SO₄	O₃SO₄	NS	O₃,SO₄
Castellsague	28	1995	Barcelona	ER	S		+	+	+	BS	—	BS, NO₂	BS,NO₂	—
Cody	29	1992	N Jersey	ER	S	May–Aug	+	—	+	—	—	—	—	O₃
Delfino	30	1994	Montreal	Ads	S	Jun–Sept	+	—	—	PM₁₀,PM_2.5H⁺,SO₄	—	—	_—	PM₁₀,SO₄
Schouten	31	1996	Amsterdam	Ads	S	Apr–Sept	+	+	+	BS	—	—	—	SO₂
Steib	32	1996	St John, NB	ER	S	May–Sept	+	+	+	SO₄,TSP	NS	O₃	O₃	O₃
Thurston	33	1994	Toronto	Ads	S		+	—	—	SO₄,H⁺	—	—	—	O₃,SO₄,H⁺
Thurston	34	1992	New York	Ads	S		+	—	—	SO₄,H⁺	—	—	—	O₃,SO₄,H⁺
Walters	35	1994	B’ham, UK	Ads	S	June–Aug	—	—	+	BS	—	—	—	NS
Anderson	This paper		London	Ads	W	Oct–Mar	+	+	+	BS	(O₃),NO₂	NS	NO₂,SO₂,BS	(O₃),NO₂,SO₂,BS
Bates	25	1990	Vancouver	ER	W		+	+	+	SO₄,COH	NS	NS	SO₂,SO₄	—
Bates	26	1987	Ontario	Ads	W	Jan–Feb	+	+	+	SO₄,COH	(O₃)	—	—	NS
Castellsague	28	1995	Barcelona	ER	W		+	+	+	BS	—	NO₂	—	—
Schouten	31	1996	Amsterdam	Ads	W	Oct–Mar	+	+	+	BS	—	—	—	NS
Walters	35	1994	B’ham, UK	Ads	W	Dec–Feb	—	—	+	BS	—	—	—	BS,SO₂

Ads = admissions; ER = emergency room admissions or attendance at accident and emergency departments; TSP = total suspended particles; PM = suspended particles; SO₄ = sulphate; COH = coefficient of haze; H⁺ = hydrogen ion concentration (a measure of acid aerosols); AY = all year; S = summer/warm season; W = winter/cool season; BS = black smoke; NS = no pollutant significant, — = no information on that age group.