Occupation, chronic bronchitis, and lung function in young adults - An international study

We studied the relationship between occupational exposures, chronic bronchi tis, and lung function in a general population survey in 14 industrialized countries, including 13,253 men and women aged 20 to 44 yr. We studied asso ciations between occupational group, occupational exposures, bronchitis sym ptoms (cough and phlegm production for at least 3 mo each year), FEV1, and nonspecific bronchial responsiveness (NSBR) separately in lifetime nonsmoke rs, cigarette smokers, and ex-smokers. Occupational exposure to vapors, gas , dust, or fumes, estimated with a job exposure matrix (JEM), was associate d with chronic bronchitis among current smokers only (prevalence ratio (PR) : 1.2 to 1.7). The interaction of occupational exposure with smelting, howe ver, was not statistically significant (p > 0.1). Self-reported exposure wa s related to chronic bronchitis in all smoking groups. An increased risk fo r chronic bronchitis was found in agricultural, textile, paper, wood, chemi cal, and food processing workers, being more pronounced in smokers. Lung fu nction and NSBR were not clearly related to occupational exposures. Finding s were similar for asthmatic and nonasthmatic subjects. in conclusion, occu pational exposures contributed to the occurrence of chronic (industrial) br onchitis in young adults. Fixed airflow limitation was not evident, probabl y due to the relatively young age of this population.