[Work activities and the risk of multiple myeloma. A case-control study]

The incidence of multiple myeloma is increasing in western countries, and several environmental and occupational risk factors have been suggested to explain this trend. A case-control study was conducted in order to investigate the relationship between occupation, exposure to chemicals, and risk of multiple myeloma. A total of 170 cases of multiple myeloma, 98 males and 72 females, aged 43-84 (mean age = 67 D.S. = 10), and 170 matched hospital controls (mean age = 68 D.S. = 9) were identified for the years 1970-1988. All subjects were interviewed about socioeconomic status, current or previous occupation, and if they had ever been exposed to one or more of a list of toxic substances. Exposure were grouped in 21 risk categories. Poor socioeconomic status was associated with a significant risk for multiple myeloma (OR = 2.8; 95% Confidence Interval: 1.61-3.05), as well as agricultural work (OR = 2.71; 95% CI: 1.87-4.42), and work in industry (OR = 3.20; 95% CI: 2.00-5.75). Regarding toxic substance exposure, a significant association was found for asbestos (OR = 4.00; 95% CI: 2.02-8.05), mineral oils (OR = 3.00; 95% CI: 1.98-5.08), pesticides (OR = 2.83; 95% CI: 1.87-4.78), and radiation (OR = 9.00; 95% CI: 0.81-21.73). No significant association was demonstrated for alcohol intake and tobacco smoking. High odds ratios were also found for fertilizers, paints, cosmetics and/or hairdressing products, and dust. These findings agree with previously reported studies, suggesting a relationship between some occupational exposures and the risk of multiple myeloma. The data, however, require clarification in prospective, larger, population-based studies.