Table 2.
The percentage of observations above LOD, GM (95% CI), and distribution percentiles for urinary total arsenic and arsenic species concentrations for cases and controls.
| Unadjusted (μg/L) | SG-adjusted (μg/L) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| % > LOD | GM (95% CI) | P50 | P75 | P90 | GM (95% CI) | P50 | P75 | P90 | ||
| Total As | Cases | 96.9 | 6.03 (4.83–7.53) | 5.39 | 10.20 | 19.45 | 6.76 (5.57–8.20) | 5.59 | 10.79 | 17.33 |
| Controls | 99.2 | 6.56 (5.80–7.41) | 5.74 | 9.88 | 21.15 | 7.32 (6.55–8.18) | 6.04 | 10.29 | 20.47 | |
| iSumAsa | Cases | 4.83 (4.05–5.76) | 3.02 | 6.46 | 10.90 | 4.62 (3.87–5.52) | 3.13 | 6.05 | 8.88 | |
| Controls | 4.63 (4.19–5.12) | 3.42 | 5.56 | 10.27 | 4.46 (4.04–4.94) | 3.28 | 5.74 | 10.24 | ||
| As3 | Cases | 10.9 | - | < LOD | < LOD | 0.49 | - | < LOD | < LOD | 0.37 |
| Controls | 14.8 | - | < LOD | < LOD | 0.56 | - | < LOD | < LOD | 0.44 | |
| As5 | Cases | 18.8 | - | < LOD | < LOD | 1.16 | - | < LOD | < LOD | 1.24 |
| Controls | 15.6 | - | < LOD | < LOD | 1.70 | - | < LOD | < LOD | 1.70 | |
| iAsb | Cases | 1.37 (0.91–2.07) | < LOD | 0.50 | 1.61 | 1.24 (0.81–1.91) | < LOD | 0.37 | 1.56 | |
| Controls | 1.37 (1.09–1.73) | < LOD | 0.55 | 1.88 | 1.36 (1.02–1.82) | < LOD | 0.38 | 1.78 | ||
| MMA | Cases | 9.4 | - | < LOD | < LOD | < LOD | - | < LOD | < LOD | < LOD |
| Controls | 11.0 | - | < LOD | < LOD | 0.98 | - | < LOD | < LOD | 0.63 | |
| DMA | Cases | 68.8 | 4.22 (3.53–5.03) | 2.66 | 4.37 | 10.70 | 4.00 (3.32–4.82) | 2.59 | 4.52 | 8.10 |
| Controls | 76.4 | 4.26 (3.90–4.65) | 3.18 | 4.86 | 8.16 | 3.93 (3.59–4.30) | 2.90 | 4.41 | 7.25 | |
| AsB | Cases | 25.0 | - | < LOD | 0.66 | 6.40 | - | < LOD | 0.70 | 7.46 |
| Controls | 23.2 | - | < LOD | < LOD | 5.98 | - | < LOD | < LOD | 5.72 | |
| AsC | Cases | 1.6 | - | < LOD | < LOD | < LOD | - | < LOD | < LOD | < LOD |
| Controls | 1.3 | - | < LOD | < LOD | < LOD | - | < LOD | < LOD | < LOD | |
| TMO | Cases | 1.6 | - | < LOD | < LOD | < LOD | - | < LOD | < LOD | < LOD |
| Controls | 2.5 | - | < LOD | < LOD | < LOD | - | < LOD | < LOD | < LOD | |
Abbreviations: Total As, urinary total arsenic; iSumAs, Sum of urinary inorganic-related arsenic species; As3, arsenite; As5, arsenate; iAs, inorganic arsenic; MMA, monomethylarsonic acid; DMA, dimethylarsinic acid; AsB, arsenobetaine; AsC, arsenocholine; TMO, trimethylarsine oxide; SG, specific gravity; LOD, limit if detection; GM, geometric mean.
One participant was unavailable for As3, As5, MMA, DMA, AsB, AsC, and TMO, due to insufficient sample.
The detectable proportions of As3, As5, MMA, AsB, AsC, and TMO were below 40%; thus, the GM was not summarized for these species.
iSumAs = As3 + As5 + MMA + DMA
iAs = As3 + As5