Table 2. Dose-response of distance of maternal address from the well and LBW.

Effect of maternal residence within the impact zones on LBW, across varying distances from the leaking well SS-25 during the late pregnancy exposure period. All births across LA County are included as the reference. Late pregnancy exposure period: DOB: 23 October 2015 to 11 April 2016. REF, reference.

Maternal residence distance from SS-25	Full 10-km S buffer		Middle/Western segments
	OR (95% CI)	P for trend	OR (95% CI)	P for trend
>15 km	REF	4.8 × 10−4	REF	7.8 × 10−3
10–15 km	1.15 (1.00, 1.33)		0.97 (0.78, 1.21)
5–10 km	1.45 (1.11, 1.90)		1.76 (1.25, 2.48)
<5 km	1.61 (0.77, 3.36)		2.02 (0.91, 4.47)