| Duration of employment | ||||||||
---|---|---|---|---|---|---|---|---|---|
Category of Work | < 5 years |  | ≥ 5 years |  |  | Total | |||
 | Obs | SMR |  | Obs | SMR |  | Obs | SMR |  |
Electrolysis:1 | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   First exposure: 1946–1955 | 10 | 318 | * | 16 | 482 | *** | 26 | 402 | *** |
   First exposure: 1956–1969 | 1 | 152 |  | 3 | 448 |  | 4 | 300 |  |
   Electrolysis: Total | 11 | 289 | * | 19 | 476 | *** | 30 | 385 | *** |
Roasting, Smelting and Calcining:2 | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   First exposure: 1946–1955 | 5 | 211 |  | 7 | 298 |  | 12 | 254 | ** |
   First exposure: 1956–1969 | 1 | 139 |  | 1 | 128 |  | 2 | 133 |  |
   RSC: Total | 6 | 194 |  | 8 | 254 | * | 14 | 225 | ** |
Other KNR Departments:3 | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   Low level exposure4 | 1 | 73 |  | 5 | 267 |  | 6 | 187 |  |
   Unexposed4 | 4 | 349 |  | 2 | 93 |  | 6 | 183 |  |
   Other departments: Total5 | 5 | 250 |  | 18 | 275 | ** | 23 | 283 | ** |
Refinery: Total6 | 22 | 247 | ** | 45 | 334 | *** | 67 | 299 | *** |