The effects of long-term occupational exposure to dust from herbs

Introduction: Herbs are a heterogeneous group of many species with several thousand plants, which are used in large quantities in the pharmaceutical and food industries. The aim of the study was to analyse the health effects of long-term occupational exposure to dust from herbs. Methods: A group of 150 people occupationally exposed to dust from herbs, consisting of farmers and workers from herbs processing industry, was examined. As a reference group, 50 urban dwellers not exposed to any kind of organic dust were examined. Examined people were interviewed with the help of the ATS questionnaire compiled by Ferris and by the questionnaire developed in the Institute of Agricultural Medicine in Lublin, Poland for examination of work-related symptoms caused by organic dust. The lung function examination (vital capacity (VC), forced expiratory volume in the first second (FEV₁), and FEV₁/VC (%) of normal ranges) and allergological tests (skin prick test, precipitin test and inhibition of leukocyte migration (MIF) test) with microbial antigens were conducted. Results: 71.3% (95% CI 64.1–78.6%) of the exposed people reported occurrence of work-related symptoms. A post-shift decrease of spirometric values (VC, VC%) was observed in the exposed group (mean decrease 2.6%, P<0.01). A significant relationship was found between the number of work-related symptoms and decrease of FEV₁ values, both before (Spearman correlation coefficient r=−0.21, P<0.05) and after work (r=−0.31, P<0.01). In allergological tests, the frequencies of positive reactions in the exposed group were significantly higher than in the reference group. Precipitins specific to Pantoea agglomerans were found in 30.6% (95% CI 23.2–38.1%) of exposed, compared to 12.0% among unexposed (P=0.01). The frequency of positive results in the migration inhibition test was significantly higher among exposed workers for all antigens tested. Conclusion: Long-term exposure to dust from herbs causes work-related symptoms and decrease of lung function parameters, which, finally, may lead to occupational disease.