RESUMO
BACKGROUND: Studies of association among parental atopy, tobacco exposure (passive or active) and adult asthma have provided conflicting results. OBJECTIVE: To determine the relationship among parental atopy, smoking, exposure to tobacco smoke, allergic rhinitis, work environment and asthma in adults. MATERIAL AND METHODS: In a population of 329,219 inhabitants of a geographically defined area in Northeastern of Mexico, we identified 791 cases of asthma. The patients were 20 to 54 years old, and were divided in three groups: with asthma in remission (263 patients), with symptoms since childhood (270 patients), and with asthma onset in adult age (258 patients). We included 793 randomly selected control subjects. Information on family atopy, passive and active smoking, allergic rhinitis and workplace conditions were collected by using a questionnaire. RESULTS: Parental atopy history, active smoking, allergic rhinitis and pollution in the workplace induce asthma symptoms. Exposure to smoking is a risk factor of persistence of asthma symptoms in adults (OR = 1.33; IC 95%, 1.07-1.66), but no of their development (OR = 1.10; IC 95%, 0.87-1.39). Working in a polluted environment had not significance in remission of asthma (OR =1.32; IC 95%, 0.95-1.85). CONCLUSIONS: Results support hypothesis that family atopy, active smoke, allergic rhinitis and pollution favor the persistence of asthma symptoms and increase the risk of asthma in adults.