Relative risks (and 95% confidence intervals) for non-Hodgkin’s lymphoma and 1993 nitrate concentration in community water supplies for the total population and by sex
| Total | Men | Women | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Nitrate concentration (mg NO3−/l) | Cases | P-Y | IRR (95% CI) | Cases | P-Y | IRR (95% CI) | Cases | P-Y | IRR (95% CI) |
| ⩽2.0 | 113 | 1301554 | 1.0 | 46 | 638266 | 1.0 | 67 | 663288 | 1.0 |
| 2.01–3.0 | 119 | 1270287 | 1.13 (0.87 to 1.47) | 57 | 627826 | 1.29 (0.87 to 1.92) | 62 | 642461 | 1.02 (0.71 to 1.45) |
| 3.01–4.0 | 94 | 896781 | 1.21 (0.91 to 1.61) | 56 | 444334 | 1.70 (1.13 to 2.56) | 38 | 452447 | 0.86 (0.56 to 1.30) |
| 4.01–5.0 | 138 | 1398393 | 1.15 (0.88 to 1.49) | 71 | 686981 | 1.42 (0.96 to 2.10) | 67 | 711412 | 0.95 (0.66 to 1.37) |
| 5.01–7.0 | 103 | 1242462 | 1.01 (0.76 to 1.33) | 62 | 604807 | 1.46 (0.99 to 2.16) | 41 | 637655 | 0.69 (0.46 to 1.03) |
| 7.01–10.0 | 46 | 376247 | 1.40 (0.99 to 1.99) | 28 | 184715 | 1.98 (1.23 to 3.20) | 18 | 191532 | 0.98 (0.57 to 1.66) |
| 10.01–15.0 | 91 | 953026 | 1.0 (0.74 to 1.36) | 54 | 454833 | 1.45 (0.95 to 2.22) | 37 | 498193 | 0.69 (0.44 to 1.07) |
| 15.01–26.64 | 33 | 317724 | 1.32 (0.88 to 1.97) | 17 | 157409 | 1.64 (0.92 to 2.91) | 16 | 160315 | 1.10 (0.63 to 1.93) |