Rheumatic diseases occur more frequently in certain occupations than in others.
Surveys in coal mines have indicated a greater loss of work from rheumatic complaints than in the general population; from the age of 30 miners lose more work than non-miners and prolonged incapacity is not unusual. Miners suffer mainly in the low-back, thighs and knees, with associated degenerative changes in the lower dorsal and lumbar intervertebral discs and in the knee joints. Radiological studies have shown moderate or severe changes of disc degeneration more than twice as often in miners as in other manual workers and six times as often as clerks and other office staff. Building operatives have similar symptomatology to miners but lose more work despite fewer radiological changes. On the other hand, foundry workers, especially those who are exposed to radiation from molten metal have fewer complaints and lose less work than miners despite a rather greater frequency of radiological change, particularly in the lumbar spine. Osteoarthrosis of the elbows is increased in miners, building operatives and workers using pneumatic drills. Cervical disc degeneration is common in dentists but is also a feature of rheumatic disease in workers in certain countries (for example Jamaica) where it is customary to carry heavy loads on the head; despite severe radiological changes, there are few symptoms. In farmers in temperate climates sciatic pain appears to be a more frequent complaint. In cotton spinners and weavers, the finger joints are mainly affected, the changes being those of osteoarthrosis, often with Heberden's nodes; symptoms, however, are infrequent and the incapacity slight.