Work-related symptoms and diseases of 190 currently exposed compost workers, 59 former compost workers, and 38 nonexposed control subjects were investigated in a cross-sectional study. Using a standardized questionnaire, participants were asked for work-related symptoms, exposures to bioaerosols, atopic diseases, and smoking habits. The subjects underwent a physical examination and a lung function test. In addition, total immunoglobulin (Ig) E, IgE specific to environmental allergens and moulds, and IgG specific to molds and actinomycetes were quantified. Compared to controls, compost workers suffered more often from cough and irritation of the eyes in terms of mucosal membrane irritation (MMI). Former compost workers reported similar work-related complaints, but most MMI symptoms had improved after termination of bioaerosol exposure. In contrast, cough and dyspnea persisted, indicating a chronic process. Lung function parameters of compost workers were within the reference ranges. Nevertheless, forced vital capacity (FVC) was significantly lower than for controls. Specific IgE to environmental allergens and molds was positive in 25.3% and 7.4%, respectively, of currently exposed compost workers. There were no marked differences in IgE and IgG concentrations among the three groups. Compost workers suffered with a higher frequency from cough and MMI symptoms. The findings that MMI symptoms improved in former compost workers after leaving the job confirmed the association with bioaerosol exposure. Further, the reduced FVC may be produced by this exposure. There was no higher frequency of mold sensitization in the group of compost workers compared to controls, which may be an indication of a healthy worker survivor effect.

No abstract

Waste collectors may suffer from acute and chronic health effects caused by organic dust (bioaerosols). Pathophysiological symptoms may originate either from allergic or irritative pathomechanisms, but an explicit distinction of the etiology is often complicated although crucial for proper risk assessment and workplace prevention. In this cross-sectional study, a total of 69 male waste collectors from the Ruhr area in Germany underwent a customized testing protocol including a modified questionnaire, basic clinical examination, spirometry, and immunologic parameters. Subjects were classified according to their work tasks into loaders (n=27), floaters (n=29), and drivers (n=13). We found that a high percentage of the workers had complaints (eyes 29.0%, nose 39.1%, and cough 34.8%) which were strongly work-related. Multiple logistic regression analyses indicated that duration of employment in waste collection (per 10 years) was associated with an increased prevalence of cough (OR=1.64, 95% CI 0.81; 3.35) and chronic bronchitis (OR=2.18, 95% CI 0.80; 5.92). An association between rhinitis and cough (OR=2.62, 95% CI 0.94; 7.27) was found, which supports the association between the prevalence of upper and lower airway disease. Furthermore, when adjusting for smoking status, atopic subjects suffered more frequently from irritation of the lower airways as indicated by cough (OR=2.71, 95% CI 0.91; 8.08). In conclusion, the study demonstrates associations between the prevalence of upper and lower airway disease in waste collectors. Notably, an underlying allergic disease in waste collectors could be suspected more commonly than previously reported.

Our results suggest that chronic exposure to bioaerosols in composting plants is related to a significantly higher risk for cough with phlegm, indicating chronic bronchitis. However, compost workers showed no higher incidence of deterioration of pulmonary function over the study.

Waste collectors are exposed to a heterogeneous mixture of bioaerosols able to induce health effects. The study aim was to evaluate inflammatory processes in blood and in the respiratory tract via analysis of atopy and club cell secretory protein 16 (CC16) in serum, exhaled nitric oxide (FeNO), and cellular and soluble mediators in nasal lavage fluid (NALF) and induced sputum (IS). Sixty nine current waste collectors (48% smokers) and 28 former waste collectors (25% smokers) were included in the cross-sectional study. In both groups, 63 and 64% of workers reported complaints of the eyes, nose and/or upper airways. Thirty two percent of the current and 25% of the former workers were classified as atopics. More atopics suffered from rhinitis and conjunctivitis than non-atopics (64% vs. 40% in current workers; 71% vs. 40% in former workers). CC16 values of present non-smokers were significantly higher compared to smokers. In total, FeNO values of 31 participants were lower than 10 ppb, 94% of them were smokers and 85% had respiratory symptoms of lower airways. Most of the IS biomarkers were significantly higher in smokers than in non-smokers. Non-smoking workers with respiratory symptoms of lower airways had slightly elevated mediator IS concentrations compared to asymptomatic non-smokers. We conclude that inflammatory changes in waste collectors are detectable in the content of IS biomarkers, exhaled NO, and serum CC16, which all are influenced by the smoking habit. No significant differences in biomarkers are detectable between current and former waste collectors.