The objective of this proposal is to complete a ten-year longitudinal study of textile workers in Shanghai, China in order to address some of the unanswered questions regarding longterm exposure to organic dust and chronic lung disease. The population under study has been followed since 1981 and is unusually well suited for epidemiologic study. low turnover, access to subjects who have retired, low smoking prevalence among women, reliable baseline data, suitable comparison group studied in identical fashion, and good cooperation. Exposure to gram negative bacterial endotoxin has been described in laboratory studies as producing acute respiratory symptoms and lung function change. Similar observations have not yet been reported from field surveys. To date, no other epidemiologic study has addressed the relative contributions of cotton dust and endotoxin in producing both acute and chronic respiratory effects. The role of endotoxin is important not only in the cotton textile industry, but also in a multitude of other environments where significant levels of endotoxin have been found animal confinement buildings, sewage treatment plants, woodchip processing and sawmills, grain processing and storage, and humidified office buildings. Any attempt to respond to calls to set a permissible exposure limit for endotoxin for these environments is premature without more epidemiologic evidence for the effect of endotoxin on health - both acute and chronic. The population being followed includes 447 cotton textile workers and 465 silk textile workers surveyed with pulmonary function, symptom questionnaire and exposure assessment in 1981. All available subjects were resurveyed in 1986 and the current proposal will repeat the survey on these as well as retirees not contacted in 1986. The study will estimate the rate of annual decline in pulmonary function and compare decline between cotton and silk textile workers adjusting for appropriate confounders. The relationship between annual decline and respiratory symptom prevalence, incidence, and persistence will be examined. Best estimates of exposure to cotton dust and endotoxin for both acute and longitudinal study of outcome measures will be developed. Specific evaluation of the importance of source of cotton, duration of storage, season of use, and correlation of cotton dust and endotoxin levels in different work locations will be undertaken. Relationships for males and females will be explored through improved characterization of true differences in exposures for males and females within work areas.
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