Table 3

Poisson GLM

	Unadjusted			Adjusted
	IRR	P value	CI	IRR	P value	CI
Railyard directionality
South	-ref	---	---	-ref	---	---
North	1.38	<0.001	1.35 to 1.41	1.13	<0.001	1.11 to 1.16
Railyard distance—standardised	0.69	<0.001	0.68 to 0.69	0.74	<0.001	0.73 to 0.74
TRI distance—standardised	0.80	<0.001	0.79 to 0.81	0.92	<0.001	0.91 to 0.93
Highway distance—standardised	0.85	<0.001	0.84 to 0.86	0.90	<0.001	0.90 to 0.91
Incidence rates for acute asthma (N=428)
Railyard directionality
South	ref	–	–	Ref	–	–
North	1.91	<0.001	1.15 to 1.24	1.01	0.675	0.97 to 1.05
Railyard distance—standardised	0.71	<0.001	0.70 to 0.72	0.78	<0.001	0.76 to 0.79
TRI distance—standardised	0.78	<0.001	0.77 to 0.80	0.89	<0.001	0.87 to 0.90
Highway distance—standardised	0.83	<0.001	0.82 to 0.84	0.87	<0.001	0.85 to 0.88

Adjusted incidence rate ratios (IRR) are based on Poisson models that included railyard directionality, railyard distance, TRI distance and highway distance. Incidence rates for all asthma (N=428).
TRI, toxic release inventory.