Table 1.
Characteristics of the Estonian cohort of Chernobyl cleanup workers.
| Characteristic | No. | % |
|---|---|---|
| Total | 4,810 | 100 |
| Vital status on December 31, 2011 | ||
| Living in Estonia | 3,229 | 67.1 |
| Dead | 1,018 | 21.2 |
| Emigrated | 563 | 11.7 |
| Age at start of follow-up (full years) | ||
| <20 | 80 | 1.7 |
| 20–29 | 1,846 | 38.4 |
| 30–39 | 2,309 | 48.0 |
| 40–49 | 541 | 11.2 |
| ≥50 | 34 | 0.7 |
| Time of arrival in the Chernobyl area | ||
| 1986, April–May | 1,393 | 29.0 |
| 1986, June–December | 1,508 | 31.4 |
| 1986, month unknown | 22 | 0.5 |
| 1987 | 1,086 | 22.6 |
| 1988 | 564 | 11.7 |
| 1989–1991 | 109 | 2.3 |
| Unknown | 128 | 2.7 |
| Duration of stay in the Chernobyl area (days) | ||
| <30 | 270 | 5.6 |
| 30–89 | 1,915 | 39.8 |
| 90–149 | 1,531 | 31.8 |
| 150–209 | 852 | 17.7 |
| ≥210 | 75 | 1.6 |
| Unknown | 167 | 3.5 |
| Documented dose (cGy) | ||
| <5.0 | 1,101 | 22.9 |
| 5.0–9.9 | 1,272 | 26.4 |
| 10.0–14.9 | 702 | 14.6 |
| 15.0–19.9 | 673 | 14.0 |
| 20.0–24.9 | 270 | 5.6 |
| ≥25.0 | 28 | 0.6 |
| Unknown | 764 | 15.9 |
| Ethnicity | ||
| Estonian | 2,353 | 48.9 |
| Non-Estonian | 2,451 | 51.0 |
| Unknown | 6 | 0.1 |
| Education | ||
| Higher | 370 | 7.7 |
| Secondary | 2,883 | 59.9 |
| Basic or less | 1,121 | 23.3 |
| Unknown | 436 | 9.1 |