Table 1

Descriptive statistics showing dates of study in each city, and the 25th, 50th, and 75th centiles of the environmental variables in each city

City	Study dates (available PM₁₀)	Temperature (°C)	Relative humidity	PM₁₀ (μg/m³)	Non-accidental deaths
Birmingham	1/4/87–31/12/93	11	62	20	60996
		18	71	31
		24	80	46
Boulder	1/1/86–31/12/93	3	40	17	7655
		11	52	25
		19	65	35
Canton	1/1/89–24/12/93	2	66	19	13677
		11	74	26
		19	82	34
Chicago	1/3/88–24/12/93	2	62	23	267147
		11	70	33
		19	79	46
Cincinnati	2/8/88–31/12/93	4	64	23	41496
		13	72	32
		21	81	44
Colorado Springs	1/7/87–24/12/93	2	39	18	12663
		11	51	23
		18	66	31
Columbus	1/1/86–31/12/93	3	64	20	28907
		12	70	28
		21	80	39
Detroit	1/5/86–24/12/93	2	64	21	145195
		11	71	32
		19	79	49
Minneapolis/St Paul	1/4/87–24/12/93	−1	60	17	75529
		9	69	24
		19	78	35
New Haven	1/5/87–31/12/91	3	57	17	32401
		12	67	26
		20	77	38
Pittsburgh	1/1/87–24/12/93	3	61	19	178649
		12	70	30
		20	79	47
Provo-Orem	1/4/87–31/12/93	3	39	21	7697
		12	52	30
		21	72	45
Seattle	1/1/86–24/12/93	7	67	18	83538
		11	77	27
		16	85	39
Spokane	1/1/86–24/12/93	2	49	23	12964
		8	68	36
		16	84	57