Occupational exposure to organic dust, microorganisms, endotoxin and peptidoglycan among plants processing workers in Poland

The objective of present work was to determine and compare the components of bioaerosol in several sectors of plant processing industries. The Study was conducted in 10 Facilities engaged in herb and grain processing, flax threshing, grain storing, baking, and cereals production. The air samples were taken on glass fibre litters with an AS-50 sampler. We determined the concentrations of airborne microorganisms, dust, endotoxin and peptidoglycan. Total concentrations of viable airborne microorganisms ranged from 0.18-861.4 x 10(3) cfu/m(3). The highest levels of microbial contamination of the air were observed at flax farms, in grain elevators and in a herb processing plant. Gram-positive bacteria aid fungi were detected at all sampling sites, and their median concentrations were respectively 18.1 x 10(3) cfu/m(3) and 0.66 x 10(3) cfu/m(3). The concentration of Gram-negative bacteria ranged from 0.0-168.0 x 10(3) cfu/m(3). The concentration of thermophilic actinomycetes ranged from 0.0-1.45 x 10(3) cfu/m(3). Qualitatively Gram-positive bacteria constituted 23-93% of the total microbial Count. The most common species were: Staphylococcus spp., Curtobacterium pusillum, Rhodococcus fascians, Aureobacterium testaceum, Sanguibacter keddieii, Microbacterium spp., and Bocillus spp. Gram-negative bacteria formed 0-48% of the total Count. The species Pantoea agglomerans dominated in all examined air samples. Fungi constituted 2.5-76.9% of the total microbial count. Among them, Penicillium spp., Mucor spp., Alternario spp., Aspergillus niger, and Aspergillus spp. were found. The dust concentration ranged from 0.18-86.9 mg/m(3). The concentration of endotoxin was large and ranged front 0.0041-1562.6 mu g/m(3). Muramic acid, the chemical marker of peptidoglycan, was detected in 9 out of 13 (69.2%) collected samples. The concentration of peptidoglycan ranged front 1.93-416 ng/m(3). A highly significant correlation was found between the individual components of bioaerosol determined in this study. The concentration of endotoxin was correlated with the concentration of Gram-negative bacteria, total microorganisms, and peptidoglycan (R>0.9, p<0.001). The concentration of peptidoglycan was correlated with the concentration of Gram-positive bacteria, Gram-negative bacteria, and total microorganisms (R>0.9, p<0.001).