The project was aimed at evaluating the potential occupational exposure of swine farm workers to dust and microorganisms present in piggery bioaerosols (especially in its respirable fraction) under various breeding conditions. Sampling was carried out in 14 buildings located at 13 pig breeding and production farms in Poland. Concentrations of inhalable and respirable dusts in the air of the piggeries were low (means, respectively, 1.76 and 0.23 mg/m 3 ). The concentration of microorganisms was generally high (mean = 3.53 9 10 5 cfu/m 3 ). More than 96% of determined microorganisms were bacteria (mean = 3.42 9 10 5 cfu/m 3 ). The fungal concentration was distinctly lower (mean = 2.71 9 10 3 cfu/m 3 ). The concentration of bacteria in the respirable fraction of bioaerosol (mean = 1.51 9 10 5 cfu/m 3 ) made up for 48.2% of their total concentration, while the level of fungi in that fraction (mean = 1.50 9 10 3 cfu/m 3 ) formed 68.8% of the total fungal concentration. The concentration of inhalable dust was significantly modified by the type of breeding system. The factors that significantly affected the total concentrations of microbes and bacteria, as well as their levels in the bioaerosols' respirable fraction were as follows: herd size, breeding system, feeding method and the type of ventilation system. In the case of fungi, these were the livestock breeding system and the feeding method. Moreover, there was a high positive correlation of inhalable dust concentrations with the fungal concentration, CO 2 and relative humidity. A negative correlation was found between concentrations of each microbe group and the airflow velocity. Swine farm workers are exposed to relatively low dust concentrations and high concentrations of microorganisms, bacteria in particular. Fungi, to a much larger extent than bacteria, are correlated with the respirable particles of a piggery bioaerosol, which may harm the respiratory system of exposed workers.

Objectives: This study is aimed at evaluation of bacterial air contamination in intensive poultry breeding. The evaluation was based on the determined levels of bacterial concentrations and qualitative identification of isolated microorganisms. Materials and Methods: The study covered 5 poultry houses: two hatcheries and three hen houses with the litter bed system. The air was sampled in three measurement series in the central part of the investigated workplace at the height of about 1.5 m over the ground, using portable measuring sets consisting of a GilAir 5 (Sensidyne, USA) pump and a measuring head filled with a glass microfibre filter (Whatman, UK). For the quantitative and qualitative analysis of microorganisms were used appropriate microbiological media. Results: The total concentrations of airborne mesophilic bacteria inside the poultry breeding houses ranged from 4. . The lowest concentrations of each group of the examined microorganisms were noted in the second measurement series when the air exchange in the breeding houses was over twice higher than in first and third measurement series because the mechanical ventilation was supported by natural ventilation (opened gates in the buildings). The lowest concentrations of total bacteria were obtained in those buildings where one-day old chickens were kept. Gram-positive bacteria of the genera: Staphylococcus, Enterococcus, Corynebacterium, Brevibacterium, Micrococcus, Cellulomonas, Bacillus, Aerococcus, and Gram-negative bacteria of the genera: Pseudomonas, Moraxella, Escherichia, Enterobacter, Klebsiella, Pasteurella, Pantoea were isolated. It was shown that for most of the investigated livestock premises the total bacteria concentrations exceeded the reference value of 1.0×10 5 cfu/m 3 . Furthermore, pathogenic microorganisms which are a potential threat to human health (Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae ssp. ozaenae, Enterococcus faecalis, Enterococcus faecium) were found among the identified bacteria. Conclusions: The results indicate that the hygienic conditions of the working environment connected with litter bed system production of poultry are affected by changes of the efficiency of ventilation and create a direct health risk to employees. They should use personal protective measures to protect their respiratory tract, especially when the gates in the hen houses are closed. Key words: Bacterial aerosol, Poultry breeding, Occupational exposure, Health risksThe project was financed with a grant for statutory activity IMP 3.2/2009 titled "Assessment of the influence of biological agents levels and irritant gases levels on the activity of the respiratory system in workers employed in poultry breeding". Project leader: Alina Buczyńska, PhD.

Objectives:The inhaled endotoxin is considered as a causative factor in the process of acute bronchial obstruction, which can be measured by a decrease in forced expiratory volume in 1 s (FEV 1 ). The aim of this study was to assess endotoxin exposure among sewage treatment plant workers (STPW) and its effect on across-shift changes in respiratory airflow. Material and Methods: A group of 78 STPW from a large sewage treatment plant was studied. Inhalable dust for endotoxin assessment was collected using personal aerosol samplers. Endotoxin was assayed with the kinetic, chromogenic Limulus amebocyte lysate test. Across-shift spirometric measurements were performed on Mondays, after 2-days absence from work, with the use of portable spirometer. The forced vital capacity (FVC), and FEV 1 parameters were analyzed. Multifactor regression modeling was performed to determine parameters significantly associated with endotoxin exposure. , geometric standard deviation (GSD) = 4.21). Through the use of multifactor analysis, which excluded the main confounders (inhalable dust and smoking habit) it was found that, despite low levels of endotoxin, it had significant impact on the observed across-shift decline in FEV 1 (p = 0.044). For this parameter, the regression slope was additionally calculated (r = -0.017, p = 0.071). Conclusions: Relatively low levels of endotoxin among sewage treatment plant workers may cause small, but significant across-shift declines in FEV 1 . The observed relationship was independent of organic dust concentrations and smoking habit. The respiratory protection should be provided for STPW.

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Objectives:The main objective of the study was to determine the levels of house dust mite (Der p1), dog (Can f1), cat (Fel d1) and cockroach (Bla g2) allergens in kindergartens localized in an urban agglomeration. Material and Methods:A quantitative analysis of allergens was carried out in settled dust samples collected by vacuuming the floor surface in three kindergartens (N = 84) and children's clothing (N = 36). The samples were collected in springsummer and autumn-winter periods as well as at the beginning and end of the week. The allergen dust concentration was determined by enzyme-linked immunoenzymatic assay (ELISA). Results: The mean geometric concentrations (±geomet-ric standard deviations) of allergens Der p1, Can f1, Fel d1 and Bla g2 determined in kindergartens were: 0.02±3.21 μg/g of dust; 0.97±4.49 μg/g of dust; 0.30±4.43 μg/g of dust and 0.01±3.08 μg/g of dust, respectively. Younger classrooms (children aged from 3 to 4 years) were characterized by almost twice higher mean concentration of allergen Fel d1, as compared to older classrooms (children aged from 5 to 6 years) (p < 0.05). A significant impact of seasonality on the level of dog allergen Can f1 was found (p < 0.05). No significant weekly variation was found in average concentrations of the allergens. Children who had a dog and/or cat at home were characterized by high concentrations of allergens Can f1 and Fel d1 on their clothes (59.2±5.39 μg Can f1/g of dust; 3.63±1.47 μg Fel d1/g of dust), significantly higher than concentrations of allergens in children who did not have any pets (p < 0.001). Conclusions: Special attention should be paid to keeping the kindergarten rooms tidy and clean and to an appropriate choice of furnishings and fittings which would prevent the proliferation of the house dust mite and accumulation of allergens.