Table 1.

Summary statistics.

	Full sample			Analytic sample
	Mean	Range	N	Mean	Range	N
3-yr mortality rate among
75± year olds from:
All causes	0.157	0.000–0.857	27,908	0.155	0.000–0.833	9027
	(0.178)			(0.181)
Cardio-respiratory	0.103	0.000–0.800	27,908	0.103	0.000–0.800	9027
	(0.145)			(0.148)
Cancer	0.029	0.000–0.667	27,908	0.029	0.000–0.667	9027
	(0.076)			(0.078)
External causes	0.002	0.000–0.500	27,908	0.002	0.000–0.500	9027
	(0.019)			(0.020)
Other variables
Frequency downwind	0.150	0.003–0.490	27,908	0.152	0.003–0.490	9027
of major highway	(0.130)			(0.129)
Frequency dead wind	0.423	0.101–0.660	27,908	0.421	0.101–0.660	9027
	(0.135)			(0.131)
Population	164.8	1–6375	27,908	166.9	1–2215	9027
	(180.2)			(167.6)
Population aged 75+	8.5	1–542	27,908	6.7	1–154	9027
	(15.1)			(7.3)
Distance to highway	1182	0–7666	27,908	313	50–600	9027
(meters)	(1035)			(158)
Share owner occupied	0.548	0–1	27,869	0.518	0–1	9022
	(0.323)			(0.315)
Share black	0.143	0–1	27,908	0.119	0–1	9027
	(0.240)			(0.202)
Share aged 75+	0.064	0–1	27,908	0.053	0–1	9027
	(0.071)			(0.058)

Notes: The observation is the census block. Parentheses contain standard deviations. The analytic sample is limited to census blocks with centroids between 50 and 600 m from major highways.