A 5-year follow-up study on respiratory disorders and lung function in workers exposed to organic dust from composting plants
To evaluate acute and chronic effects of long-term exposure to organic dust on respiratory disorders and lung function among employees at 41 composting facilities in Germany.
A total of 218 compost workers and 66 control subjects were enrolled in the cohort. They were evaluated using a standardized questionnaire, a clinical examination, and spirometric measurements. Changes of symptoms, respiratory disorders, and lung function were determined in a first survey after 5 years of exposure in 123 compost workers and 48 controls. Exposure measurements were performed at six composting facilities for respirable dust, cultivable microorganisms, and endotoxins.
Exposure measurements revealed high concentrations of thermo-tolerant/thermophilic actinomycetes and filamentous fungi in the bioaerosols at the composting sites. A significantly higher job fluctuation was observed among the compost workers compared to control subjects (95 vs. 18; p < 0.05). Compost workers reported a significantly higher prevalence of mucosal membrane irritation (MMI) of the eyes and upper airways than control subjects. Conjunctivitis was diagnosed significantly more often in compost workers. Forced vital capacity in percent of predicted (FVC%) of the non-smoking compost workers declined significantly (−5.4%) during the observation period compared to control subjects. The decline of FVC% in 16 compost workers exceeded 10% of initial values. A significant increase was observed in the number of compost workers suffering from chronic bronchitis (RR = 1.41; 95% CI = 1.28–1.55). Allergic alveolitis was diagnosed clinically in two compost workers.
The exposure to organic dust at workplaces of composting facilities is associated with adverse acute and chronic respiratory health effects, including MMI, chronic bronchitis, and an accelerated decline of FVC%. The pattern of health effects differs from those at other workplaces with exposures to organic dust possibly due to high concentrations of thermo-tolerant/thermophilic actinomycetes and filamentous fungi at composting plants.
KeywordsBioaerosol exposure Organic dust Lung function Chronic bronchitis Hypersensitivity pneumonitis
The authors thank Rose-Marie Marquordt for her excellent technical assistance. The study was supported by a grant of the German Federal Institute for Occupational Safety and Health (F5184).
- American Thoracic Society (1998) Respiratory health hazards in agriculture. Am J Respir Crit Care Med 158:S1–S76Google Scholar
- American Thoracic Society (1995) Standardization of spirometry: 1994 update. Am J Respir Crit Care Med 152:1107–1136Google Scholar
- Clark CS, Bjornson HS, Schwartz-Fulton J, Holland JW, Gartside PS (1984) Biological health risks associated with the composting of wastewater treatment plant sludge. J Water Pollut Control Fed 56:1269–1276Google Scholar
- Göttlich E, Engesser KH, Bardtke D (1994) Emissions of fungal spores at waste treatment industries. Forum Städte-Hyg 45:321–325Google Scholar
- Kutzner HJ, Kempf A (1994) Emissions of actinomycete spores in composting plants and other waste treatment industries. Forum Städte-Hyg 45:326–330Google Scholar
- Quanjer PH, Tammeling GJ, Cotes JE, Pedersen OF, Peslin R, Yernault JC (1993) Lung volumes and forced ventilatory flows. Report of working party, standardization of lung function tests, European Community for Steel and Coal. Official statement of the European Respiratory Society. Eur Respir J 16(Suppl 16):5–40Google Scholar
- Rylander R (1994) Organic dusts—from knowledge to prevention. Scand J Work Environ Health 20(special issue):116–122Google Scholar
- Rylander R, Carvalheiro MF (2006) Airway inflammation among workers in poultry houses. Int Arch Occup Environ Health Jan 4:1–4 [Epub ahead of print]Google Scholar
- Schappler-Scheele B, Schürmann W, Hartung J, Missel T, Benning C, Schröder H, Weber J (1999) Study of the health risks of employees in compost preparation plants. Research Report 844, Schriftenreihe der Bundesanstalt für Arbeitsschutz und Arbeitsmedizin Dortmund/Berlin, NW-Wirtschaftsverlag, Bremerhaven, Germany, pp 65–111Google Scholar
- Schmidt B, Philipp W (1994) Emissions of bacteria in composting plants and other waste treatment industries. Forum Städte-Hyg 45:331–337Google Scholar
- Stalder K, Bünger J (1996) Health risks from facultative pathogenic microorganisms in garbage handling: aspects of environmental and occupational medicine. Forum Städte-Hyg 47:142–146Google Scholar
- Streib R, Botzenhart K, Drysch K, Rettenmeier AW (1996) Staub- und Keimzahlmessungen bei der Anlieferung, Sortierung und Kompostierung von Hausmüll und hausmüllähnlichem Gewerbeabfall Zentralbl Hyg Umweltmed 198:531–551Google Scholar