Table 4 Adjusted prevalence ratios for lifetime and current asthma by environmental exposure

Road miles/sq. mi

 Tertile 1 (0.19–1.89)

Ref

––-

Ref

––-

 Tertile 2 (2.18–2.76)

1.22

0.88–1.71

1.61

1.04–2.48

 Tertile 3 (2.96–6.00)

1.56

1.14–2.14

2.00

1.32–3.03

Coal haul miles/sq. mi

 Zero

Ref

––-

Ref

––-

 Below median (0.00–0.62)

0.87

0.66–1.15

0.84

0.60–1.17

 Above median (0.72–1.27)

1.03

0.73–1.44

0.79

0.50–1.24

Oil/gas wells/sq. mi

 Zero

Ref

––-

Ref

––-

 Below median (0.34–3.51)

1.04

0.76–1.43

1.26

0.83–1.91

 Above median (4.38–8.44)

1.30

0.88–1.92

1.70

1.03–2.80

Abandoned mining, %HUC area

 Tertile 1 (0.00–8.04)

Ref

––-

Ref

––-

 Tertile 2 (9.72–44.84)

1.01

0.74–1.37

0.94

0.64–1.38

 Tertile 3 (46.40–196.45)

1.18

0.88–1.58

1.31

0.91–1.89

Active mining, %HUC area

 Zero

Ref

––-

Ref

––-

 Below median (0.00–8.02)

0.87

0.66–1.15

0.78

0.56–1.10

 Above median (9.68–48.31)

0.64

0.45–0.92

0.54

0.35–0.85