This study aimed to characterize airborne bacteria and fungi populations present in rural nursery schools in the Upper Silesia region of Poland during winter and spring seasons through quantification and identification procedures. Bacterial and fungal concentration levels and size distributions were obtained by the use of a six-stage Andersen cascade impactor. Results showed a wide range of indoor bioaerosols levels. The maximum level of viable bacterial aerosols indoors was about 2600 CFU·m −3 , two to three times higher than the outdoor level. Fungi levels were lower, from 82 to 1549 CFU·m −3 , with indoor concentrations comparable to or lower than outdoor concentrations. The most prevalent bacteria found indoors were Gram-positive cocci (>65%). Using the obtained data, the nursery school exposure dose (NSED) of bioaerosols was estimated for both the children and personnel of nursery schools. The highest dose for younger children was estimated to range: 327-706 CFU·kg −1 for bacterial aerosols and 31-225 CFU·kg −1 for fungal aerosols. These results suggest an elevated risk of adverse health effects on younger children. These findings may contribute to the promotion and implementation of preventative public health programs and the formulation of recommendations aimed at providing healthier school environments.

Indoor air quality (IAQ) in preschools is an important public health challenge. Particular attention should be paid to younger children, because they are more vulnerable to air pollution than higher grade children and because they spend more time indoors. Among air pollutants, particulate matter (PM) is of the greatest interest mainly due to its acute and chronic effects on children’s health. In addition, carbon dioxide (CO2) levels indicate ventilation conditions. In this paper, we present the concentrations of PM (PM1, PM2.5, PM10 and total—TSP) and CO2 monitored in four naturally ventilated nursery schools located in the area of Gliwice, Poland. The nursery schools were selected to characterize areas with different degrees of urbanization and traffic densities during the winter season. The results indicate the problem of elevated concentrations of PM inside the examined classrooms, as well as that of high levels of CO2 exceeding 1000 ppm in relation to outdoor air. The characteristics of IAQ were significantly different, both in terms of classroom occupation (younger or older children) and of localization (urban or rural). To evaluate the children’s exposure to poor IAQ, indicators based on air quality guidelines were proposed to rank classrooms according to their hazard on the health of children.

Abstract:The issue of healthy educational buildings is a global concern because children are particularly at risk of lung damage and infection caused by poor indoor air quality (IAQ). This article presents the results of a preliminary study of the concentration and size distribution of bacterial aerosol in three educational buildings: a preschool, primary school, and high school. Sampling was undertaken in the classrooms with an Andersen six-stage impactor (with aerodynamic cut-off diameters of 7.0, 4.7, 3.3, 2.1, 1.1 and 0.65 µm) during spring 2016 and 2017, as well as the outside of the buildings. After incubation, bioaerosol particles captured on nutrient media on Petri dishes were quantitatively evaluated and qualitatively identified. The highest average concentration of bacterial aerosol was inside the primary school building (2205 CFU/m 3 ), whereas the lowest average concentration of indoor culturable bacteria was observed in the high school building (391 CFU/m 3 ). Using the obtained data, the exposure dose (ED) of the bacterial aerosol was estimated for children attending each educational level. The most frequently occurring species in the sampled bacterial aerosol were Gram-positive cocci in the indoor environment and Gram-positive rod-forming endospores in the outdoor environment.

No abstract

Abstract:The concentrations and size distributions of culturable bacterial aerosols were measured during spring and winter in outdoor air in Gliwice, Upper Silesia, Poland. This research on culturable bacteria was carried over a period of two years. The samples were collected using a six-stage Andersen cascade impactor (with aerodynamic cut-off diameters of 7.0, 4.7, 3.3, 2.1, 1.1, and 0.65 µm). The results showed that the average concentration of culturable bacterial aerosol was 355 CFU m −3 in spring, which was four times higher than during winter (65 CFU m −3 ). Bacterial aerosol concentrations showed the unimodal size distribution with the highest range of 3.3-4.7 µm particles. The seasonal distributions of bacterial aerosol grain clearly indicate that, in winter, the size distribution of particles <7 µm is more "flattened" and is characterized by an increased share of fine fractions and a decreased share of coarse ones. Environmental parameters, such as temperature, UV radiation, relative humidity, wind velocity, as well as PM 10 and PM 2.5 concentrations, were measured in order to analyse whether environmental factors had any effect on bacterial aerosols. Statistically, the most important meteorological factors in the viability of airborne bacteria were temperature and UV radiation.

This study reports the concentrations of PM1 trace elements (As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Sb and Se) content in highly mobile (F1), mobile (F2), less mobile (F3) and not mobile (F4) fractions in samples that were collected in the surroundings of power plants in southern Poland. It also reports source identification by enrichment factors (EF) and a principal component analysis (PCA). There is limited availability of scientific data concerning the chemical composition of dust, including fractionation analyses of trace elements, in the surroundings of power plants. The present study offers important results in order to fill this data gap. The data collected in this study can be utilized to validate air quality models in this rapidly developing area. They are also crucial for comparisons with datasets from similar areas all over the world. Moreover, the identification of the bioavailability of selected carcinogenic and toxic elements in the future might be used as output data for potential biological and population research on risk assessment. This is important in the context of air pollution being hazardous to human health.

Samples of PM1 were collected in the surroundings of coking plants located in southern Poland. Chemical fractionation provided information on the contents of trace elements As, Cd, Co, Cr, Hg, Mn, Ni, Pb, Sb and Se in all mobile (F1-F3) and not mobile (F4) fractions of PM1 in the vicinity of large sources of emissions related to energochemical processing of coal during the summer. The determined enrichment factors indicate the influence of anthropogenic sources on the concentration of the examined elements contained in PM1 in the areas subjected to investigation. The analysis of health risk for the assumed scenario of inhabitant exposure to the toxic effect of elements, based on the values of the hazard index, revealed that the absorption of the examined elements contained in the most mobile fractions of particulate matter via inhalation by children and adults can be considered potentially harmless to the health of people inhabiting the surroundings of coking plants during the summer (HI < 1). It has been estimated that due to the inhalation exposure to carcinogenic elements, i.e., As, Cd, Co, Cr, Ni and Pb, contained in the most mobile fractions (F1 + F2) of PM1, approximately four adults and one child out of one million people living in the vicinity of the coking plants may develop cancer.

No abstract