Non-sensitising air pollution at workplaces and adult onset asthma -2-
AbstractPurpose This case-control study was undertaken to elucidate the controversy concerning whether low level, long-term exposure to non-sensitising air pollution at workplaces may cause asthma.Methods A case-control study of 192 adult onset asthma cases aged 20 -65 years and 323 controls was conducted in the southeast of Sweden. Cases were identified from computerised registers from the region, diagnosed 2000-2004 and diagnoses were confirmed via medical files. Referents were randomised from the population register of the region. Exposure was monitored by a 16-page questionnaire. Special attention was devoted to identifying and in the final analyses excluding subjects exposed to sensitising agents.Results Three years or more of occupational exposure to air pollution from dust, smoke, fumes or vapours before the year of diagnosis by analyses adjusting for age yielded an increased risk for asthma (OR =2.3, 95 % CI 1.2-4.2) in males, while in females no risk was seen. In a multiple logistic regression analysis in males without allergy in childhood, a significant risk was seen (OR=2.8, 95 % CI 1.07 -7.4), when subjects exposed to identified allergens were excluded. In females no excess risk was observed from occupational air pollution.
ConclusionThe results of this study support an association between occupational exposure to low level non-sensitising air pollution and adult onset asthma in males.Non-sensitising air pollution at workplaces and adult onset asthma -3-