title: Relationship between concentrations of microbiological agents in the air of agricultural settings and occurrence of work-related symptoms in exposed persons.
abstract: For assessment of the dose-response relationship between concentrations of microbial agents in the air of various agricultural settings and occurrence of work-related symptoms in exposed workers, a meta-analysis of the results obtained in 1994-2007 on the territory of eastern Poland was performed. The studies on the airborne concentrations of total culturable microorganisms, mesophilic bacteria, Gram-negative bacteria, thermophilic actinomycetes, fungi, and bacterial endotoxins, as well as on the frequency of work-related respiratory and general symptoms in the exposed workers, were carried out at grain, thyme, valerian, flax, and hop handling on farms, in cow barns, piggeries, horse stables and in a modern hatchery. The airborne concentrations of the total microorganisms were in the range of 9.2-1236.5 × 10(3) CFU/m(3) , of the total mesophilic bacteria 3.5-1225.8 × 10(3) CFU/m(3) , of Gram-negative bacteria 0.0- 46.2 × 10(3) CFU/m(3) , of thermophilic actinomycetes 0.0-7.1 × 10(3) CFU/m(3) , of fungi 2.1-77.9 × 10(3) CFU/m(3) , and of bacterial endotoxin 0.00925-429.55 µg/m(3) . The frequency of work-related symptoms ranged between 21.7-63.8%. In a meta-analysis for assessment of the correlations between the log-transformed concentrations of airborne microbial agents and the occurrence of work-related symptoms, the multiple regression test was applied. Statistically significant correlations were found between the occurrence of work-related symptoms and the concentration of total airborne microorganisms (R=0.748555; P=0.020317), mesophilic bacteria (R=0.7573; P=0.029548), Gram-negative bacteria (R=0.835938; P=0.019129), and endotoxins (R=0.705356; P=0.03378). The correlations between the concentrations of thermophilic actinomycetes and fungi, on one side, and frequency of work-related symptoms on the other, did not attain the threshold of significance (P=0.087049 and P=0.062963, respectively). Results of the meta-analysis confirm harmful health effects of the total airborne microorganisms, total airborne mesophilic bacteria, airborne Gram-negative bacteria, and airborne bacterial endotoxin on the occupationally-exposed agricultural workers, and indicate a need for the establishment of internationally recognized occupational exposure limits for these microbial agents.
authors.affiliation: Department of Pneumonology, Oncology and Allergology, Medical University of Lublin, Lublin, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Mackiewicz
authors.affiliation: Department of Biological Health Hazards and Parasitology, Institute of Rural Health, Lublin, Poland.
authors.forename: Czesława
authors.initials: C
authors.lastname: Skórska
authors.affiliation: Department of Biological Health Hazards and Parasitology, Institute of Rural Health, Lublin, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Dutkiewicz
mesh_terms: D000382:Agricultural Workers' Diseases / Q000453:epidemiology* / Q000382:microbiology; D000383:Agriculture; D000391:Air Microbiology; D000822:Animal Husbandry; D001419:Bacteria / Q000302:isolation & purification; D001424:Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D004731:Endotoxins / Q000032:analysis; D005658:Fungi / Q000302:isolation & purification; D008172:Lung Diseases, Fungal / Q000453:epidemiology / Q000382:microbiology; D011044:Poland / Q000453:epidemiology; D012140:Respiratory Tract Diseases / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D004731:Endotoxins