All subjects Percent of predicted FEV1 Percent of predicted FVC FEV1 residual (ml) FVC residual (ml) Never smokers Percent of predicted FEV1 Percent of predicted FVC FEV1 residual (ml) FVC residual (ml) Ever smokers Percent of predicted FEV1 Percent of predicted FVC FEV1 residual (ml) FVC residual (ml) Women Percent of predicted FEV1 Percent of predicted FVC FEV1 residual (ml) FVC residual (ml) Men Percent of predicted FEV1 Percent of predicted FVC FEV1 residual (ml) FVC residual (ml) 96.0 ± 13.9 101.9 ± 15.1 -127 ± 417 55 ± 532 (n = 25) 97.7 ± 14.3 104.0 ± 17.2 -77 ± 406 129 ± 603 (n = 40) 95.0 ± 13.7 100.6 ± 13.7 -158 ± 425 8 ± 484 (n = 45) 94.6 ± 12.1 100.9 ± 14.9 -153 ± 321 11 ± 480 (n = 20) 99.3 ± 17.2 104.2 ± 15.6 -66 ± 584 153 ± 636 88.1 ± 18.3 94.7 ± 15.3 -375 ± 611 -226 ± 614 (n = 8) 90.7 ± 15.1 93.3 ± 13.1 -257 ± 414 -229 ± 427 (n = 24) 87.3 ± 19.5 95.2 ± 16.2 -414 ± 667 -225 ± 672 (n = 18) 91.8 ± 15.8 98.7 ± 14.8 -210 ± 412 -35 ± 472 (n = 14) 83.5 ± 20.7 89.6 ± 15.0 -587 ± 762 -472 ± 700 Int Arch Occup Environ Health (2011) 84:591–600 Table 2 Lung function residuals (observed minus predicted) and percent of age-, sex-, and height-predicted values (mean ± SD) Peak arsenic before age 10 0–250 lg/l (n = 65) [800 lg/l (n = 32) Diff. difference, FEV1 forced expiratory volume in 1 s, FVC forced vital capacity a Adjusted for smoking, childhood secondhand smoke, wood, charcoal, or kerosene fuel use in childhood home, occupational air pollution, and education associated with a 244-ml decrease in FEV1 (P = 0.06) and a 310-ml decrease in FVC (P = 0.04). In terms of percent of predicted values, this was equivalent to 8.0% lower FEV1 and 7.9% lower FVC (P = 0.05 for both). When analyses were restricted to the 33 subjects who reported never smoking regularly, effect estimates remained high but changed dramatically with adjustment (16.9 and 19.7% decreases in FEV1 and FVC, respectively; P \ 0.05 for both), suggesting unstable results due to the small number of subjects. In analyses conﬁned to concurrently assessed Antofag- asta residents (n = 45), subjects who had either lived elsewhere or were older than 10 during the high exposure period served as the ‘‘unexposed’’ reference (n = 12). Effect estimates were similar, but the smaller sample size reduced statistical power (8.4 and 7.1% decreases in FEV1 and FVC (P = 0.10 for both)). Results were also similar when different age and arsenic concentration cut-offs were used to deﬁne early-life exposure. For example, with early- life exposure deﬁned as [200 lg/l arsenic before age 18, adjusted differences in FEV1 and FVC between exposed (n = 45) and unexposed (n = 52) were 9.5% (P = 0.02) and 11.7% (P = 0.006) (not shown in tables). Lung func- tion deﬁcits were similar (within 2% predicted) in analyses excluding the 9 participants without reproducible spirom- etry or the participants with the worst and best lung func- tion (i.e., possible outliers). Table 3 shows exposure–response relationships between peak arsenic concentration before age 10 and FEV1 and FVC, respectively (P trend = 0.03 for both). Participants Crude Diff. -7.9 -7.2 -248 -280 -7.0 -10.7 -180 -359 -7.7 -5.4 -256 -233 -2.8 -2.2 -56 -46 -15.8 -14.6 -521 -624 P value 0.01 0.02 0.01 0.01 0.12 0.06 0.14 0.07 0.03 0.08 0.03 0.06 0.22 0.30 0.28 0.37 0.01 0.005 0.02 0.005 Adjusteda Diff. -8.0 -7.9 -244 -310 -16.9 -19.7 -496 -716 -4.7 -3.7 -156 -180 -1.7 -1.6 -17 -27 -14.2 -15.8 -440 -673 595 P value 0.05 0.05 0.06 0.04 0.02 0.03 0.02 0.03 0.22 0.25 0.22 0.20 0.37 0.39 0.45 0.44 0.12 0.06 0.15 0.07 123