Table 3.

Air pollution and premature births.

Pollutant	Results	Reference
SO2	AOR = 1.21 (95% CI, 1.01–1.45) for 100 μg/m3 increase	Xu et al. 1995
TSP	AOR = 1.10 (95% CI, 1.01–1.20) for 100 μg/m3 increase
SO2	AOR = 1.27 (95% CI, 1.16–1.39) for 50 μg/m3 increase in the 1st trimester	Bobak 2000
TSP	AOR = 1.18 (95% CI, 1.05–1.31) for 50 μg/m3 increase in the 1st trimester
CO	NE	Ritz et al. 2000
NO2	NE
O3	NE
PM10	RR = 1.16 (95% 1.06–1.26) for 50 μg/m3 increase in the 1st trimester
SO2 + NO2 + PM10	AOR = 1.41 (91% CI, 1.08–1.82) comparing petrochemical and control municipalities	Lin et al. 2001a

Abbreviations: AOR, adjusted odds ratio; NE, no effect.