The influence of occupation on health--some results from a study in the UK oil industry.

This study describes the patterns of mortality of 35,000 male employees, with a minimum of 1 year's continuous service, who worked at 8 refineries in the UK in the period 1.1.50-31.10.75. The trace rate of those involved was 99.8%. Overall the ratio of observed to expected deaths was 0.84 (O = 4406, E = 5259.9, P < 0.00001). The numbers of deaths for many of the chronic degenerative diseases were lower than 'expected'. The number of observed deaths from all cancers was appreciably less than expected (O = 1147, E = 1286.4, O/E = 0.89, P = 0.00006). Lung cancer was particularly reduced (O = 416, E = 532.7, O/E = 0.78, P < 0.00001); there was no excess of leukaemia (in workers including some exposed to benzene). Other comparable studies have suggested an excess of gastrointestinal cancer. In the present study deaths from oesophageal, stomach, intestinal and rectal cancer were slightly raised for all workers (O = 346, E = 328.6, O/E = 1.05, P < 0.4); this was particularly noticeable for those joining before 1950 with long service and with increased latent interval. There were also excesses based on small numbers of deaths from nasal cancer (O = 7, E = 3.1, O/E = 2.24, P < 0.05), and melanoma (O = 14, E = 6.5, O/E = 2.16, P 0.01).