[Occupation and illness].

1. There are three kinds of work-related diseases: officially recognised occupational diseases; occupational diseases; work-related but unspecific diseases. 2. These unspecific diseases occur more often than would be by mere chance, among certain professional groups. 3. Cancer mortality may increase as a result of occupational cancer-promoting factors, whereas the overall mortality may be unaffected. 4. In such cases, the mortality of other diseases not related to the occupation, is diminished ("vicarious mortality"). 5. The overall cancer mortality is probably not greatly increased by professional influences. This mortality is nearly constant in males and tends to decrease in females. 6. A strong inequality of mortality rates has been found in various occupational groups. The reason for these discrepancies is unknown. 7. Mortality is most strongly related to the mental demands made on individuals by their profession. 8. Death through accidents is six times more frequent in the general population compared with job-related accidents. 9. Health hazard due to occupation is low in relation to mortality, but marked in work-related diseases.