Table 4.
Joint Effect of As Exposure and Low Blood Se on Risk of Skin Lesion
| As exposure measures § (Tertiles) | Blood Se > 150.2 μg/L† |
Blood Se ≤ 150.2 μg/L† |
||||
|---|---|---|---|---|---|---|
| N (Cases/Subcohort) | Median As level‡ | Rate Ratios (95% CI)* | N (Cases/Subcohort) | Median As level‡ | Rate Ratios (95% CI)* | |
| Baseline well As levels (μg/L) | ||||||
| 0.1–25.0 | 25/129 | 7.2 | 1.00 | 37/153 | 7.2 | 2.12 (1.09–4.10) |
| 25.1–117.0 | 36/140 | 67.7 | 1.70 (0.86–3.36) | 45/140 | 62.1 | 2.56 (1.33–4.94) |
| 117.1–564.0 | 87/157 | 231.7 | 3.38 (1.86–6.17) | 69/130 | 237.8 | 4.15 (2.24–7.67) |
| Time-weighted water As levels (TWA) (μg/L) | ||||||
| 0.1–29.0 | 24/123 | 8.4 | 1.00 | 34/146 | 9.0 | 2.11 (1.01–4.34) |
| 29.1–116.0 | 35/138 | 68.2 | 1.85 (0.92–3.74) | 45/131 | 63.9 | 2.62 (1.30–5.28) |
| 116.1–564.0 | 79/148 | 223.8 | 3.40 (1.75–6.63) | 64/127 | 232.2 | 4.58 (2.33–8.99) |
| Baseline blood As (μg/L) | ||||||
| 1.6–6.8 | 25/118 | 5.0 | 1.00 | 36/171 | 4.9 | 1.55 (0.82–2.92) |
| 6.9–11.3 | 39/146 | 8.9 | 1.36 (0.71–2.59) | 45/127 | 8.9 | 2.18 (1.16–4.09) |
| 11.4–63.9 | 84/162 | 17.8 | 2.50 (1.40–4.46) | 70/125 | 19.2 | 3.55 (1.94–6.50) |
| Baseline total urinary As (μg/L) ‡‡ | ||||||
| 3–54 | 27/142 | 30.6 | 1.00 | 38/141 | 30.1 | 1.68 (0.89–3.16) |
| 55–138 | 44/125 | 88.0 | 1.46 (0.78–2.71) | 49/154 | 88.7 | 2.15 (1.16–3.96) |
| 139–1220 | 77/159 | 281.2 | 2.67 (1.42–5.03) | 64/128 | 301.3 | 3.12 (1.66–5.84) |
RRs were adjusted for age, BMI, sex, and smoking status. RRs in relation to urinary As were additionally adjusted for urinary creatinine. A total of 11 subjects with unknown information on BMI were excluded from the analysis. A total of 51 subjects with unknown information on the TWA were also excluded from the calculation of RRs in relation to TWA.
Category-specific median values in the subcohort for each of the four As exposure measures in the left column.
Cut point was determined based on median value in the subcohort.
Cut points were determined based on tertile values in the subcohort.
RRs associated with total urinary arsenic were additionally adjusted for urinary creatinine level.