Table 2. Hazard ratio (HR) for all-cause mortality in childhood participants in relation to baseline, cumulative and time-weighted lifetime average arsenic exposure.

Exposure variables	Baseline participant	Person-years	Deaths	Crude HR (95% CI)	Adjusted HR† (95% CI)
Baseline arsenic in well water
<10	28901	189047	83	1.0	1.0
10–50	5092	33549	15	1.02 (0.59–1.76)	1.13 (0.65–1.96)
51–150	5634	36918	13	0.80 (0.45–1.44)	0.81 (0.45–1.46)
151–300	10329	67591	39	1.31 (0.90–1.92)	1.35 (0.92–1.97)
>300	8450	53995	35	1.48 (0.99–2.19)	1.51 (1.01–2.23)
P for trend, P<0.05Time-weighted lifetime average arsenic in well water
<10	8527	57073	24	1.0	1.0
10–50	5648	36883	17	1.09 (0.59–2.04)	1.37 (0.74–2.57)
51–150	13357	87520	44	1.19 (0.73–1.96)	1.44 (0.88–2.38)
151–300	19946	129469	56	1.03 (0.64–1.66)	1.22 (0.75–1.98)
>300	10928	70155	44	1.49 (0.91–2.45)	1.88 (1.14–3.10)
P for trend, P<0.5Cumulative arsenic in well water
<1000	19274	129798	54	1.0	1.0
1000–4000	29558	194283	88	1.09 (0.78–1.53)	1.17 (0.84–1.65)
>4000	9574	57020	43	1.80 (1.21–2.69)	1.90 (1.25–2.89)
P for trend, P<0.05

^†Adjusted with baseline age, educational attainment, SES.