Table 3.
Adjusted ORs (95% CIs) for Glioma in Relation to Categorical Indicators of Cumulative Occupational ELF (1–4 Year Exposure Time Window) and Any Metal (5-year lag) Exposure, INTEROCC study, 2000–2004, Australia, Canada, France, Germany, Israel, New Zealand, and United Kingdoma.
| Metal Exposure | Low ELF (<50th percentile) | High ELF (≥50th percentile) | High vs. Low ELF in stratum of metal | Interaction Term (multiplicative)b | ||
|---|---|---|---|---|---|---|
| Cases/Controls | OR (95% CI) | Cases/Controls | OR (95% CI) | OR (95% CI) | OR (95% CI) | |
| Never metal | 557/1791 | 1.00 (ref) | 672/1687 | 1.31 (1.14–1.51) | 1.33 (1.16–1.53) | 1.38 (0.98–1.94) |
| Ever metal | 77/242 | 0.71 (0.54–0.95) | 229/401 | 1.29 (1.05–1.59) | 1.50 (1.07–2.10) | |
| Ever vs. Never metal in stratum of ELF | 0.71 (0.53–0.96) | 0.99 (0.80–1.23) | ||||
| Never cadmium | 557/1788 | 1.00 (ref) | 672/1682 | 1.32 (1.15–1.52) | 1.33 (1.16–1.53) | 1.62 (0.65–3.99) |
| Ever cadmium | 10/29 | 0.71 (0.34–1.50) | 26/42 | 1.51 (0.90–2.55) | 1.69 (0.46–6.20) | |
| Ever vs. Never cadmium in stratum of ELF | 0.66 (0.29–1.48) | 1.17 (0.68–2.01) | ||||
| Never chromium | 557/1791 | 1.00 (ref) | 672/1687 | 1.32 (1.15–1.52) | 1.33 (1.16–1.53) | 1.37 (0.87–2.16) |
| Ever chromium | 40/107 | 0.77 (0.52–1.15) | 132/209 | 1.40 (1.08–1.82) | 1.61 (0.97–2.67) | |
| Ever vs. Never chromium in stratum of ELF | 0.76 (0.50–1.14) | 1.05 (0.80–1.37) | ||||
| Never iron | 557/1791 | 1.00 (ref) | 672/1687 | 1.32 (1.15–1.51) | 1.33 (1.16–1.53) | 1.47 (0.99–2.17) |
| Ever iron | 55/169 | 0.68 (0.48–0.95) | 171/286 | 1.31 (1.04–1.66) | 1.70 (1.15–2.53) | |
| Ever vs. Never iron in stratum of ELF | 0.67 (0.47–0.95) | 0.99 (0.78–1.27) | ||||
| Never lead | 557/1791 | 1.00 (ref) | 672/1687 | 1.32 (1.15–1.52) | 1.33 (1.16–1.53) | 1.69 (1.05–2.74) |
| Ever lead | 32/122 | 0.56 (0.37–0.85) | 114/216 | 1.25 (0.96–1.64) | 1.70 (1.00–2.86) | |
| Ever vs. Never lead in stratum of ELF | 0.53 (0.35–0.82) | 0.95 (0.72–1.25) | ||||
| Never nickel | 557/1791 | 1.00 (ref) | 672/1687 | 1.32 (1.15–1.51) | 1.33 (1.16–1.53) | 1.48 (0.98–2.23) |
| Ever nickel | 50/146 | 0.71 (0.50–1.02) | 152/235 | 1.39 (1.09–1.78) | 1.53 (0.99–2.34) | |
| Ever vs. Never nickel in stratum of ELF | 0.72 (0.50–1.05) | 1.04 (0.81–1.35) | ||||
| Never welding fumes | 557/1791 | 1.00 (ref) | 672/1687 | 1.32 (1.15–1.52) | 1.33 (1.16–1.53) | 1.81 (1.13–2.90) |
| Ever welding fumes | 33/118 | 0.57 (0.38–0.87) | 137/221 | 1.38 (1.06–1.78) | 2.04 (1.24–3.35) | |
| Ever vs. Never welding fumes in stratum of ELF | 0.55 (0.36–0.85) | 1.04 (0.79–1.36) | ||||
a
Conditional logistic regression models were stratified by country-region, sex, and five-year age groups, and adjusted for level of education. The 50th percentile of ELF among the control distribution was 0.46 μT-years.
b
p values for interaction (multiplicative scale) were as follows: metal (0.06), cadmium (0.30), chromium (0.18), iron (0.05), lead (0.03), nickel (0.06), welding fumes (0.01).