The Study of the Sterilization of the Indoor Air in Hospital/Clinic Rooms by Using the Electron Wind Generator.

(1) Background: Since exposure to airborne bacteria and fungi may be especially hazardous in hospitals and outpatient clinics, it is essential to sterilize the air in such rooms. The purpose of this study was to estimate the decrease in the concentration of airborne bacteria and fungi in the selected hospital and clinic rooms due to the work of the electron wind generator (EWG). (2) Methods: EWG is an air movement and air purification device using a sophisticated combination of electrode topology and specially designed high-voltage power supply. (3) Results: The concentration of both bacteria and fungi in the small patient's room dropped to approximately 25% of the initial (background) concentration. In the larger patient's room, the concentration dropped to 50% and 80% of the background concentration for bacteria and fungi, respectively. (4) Conclusions: The obtained data show that the studied sterilization process can be described by the exponential function of time. Moreover, the application of an activated carbon filter into EWG significantly decreases the concentration of ozone in the sterilized room. Sterilization by EWG significantly changes the characteristic of species and genera of airborne bacteria and shifts the main peak of the size distribution of airborne bacteria into the coarser bio-particles.

Influence of meteorological factors on the level and characteristics of culturable bacteria in the air in Gliwice, Upper Silesia (Poland).

Numerous studies have focused on occupational and indoor environments because people spend more than 90% of their time in them. Nevertheless, air is the main source of bacteria in indoors, and outdoor exposure is also crucial. Worldwide studies have indicated that bacterial concentrations vary among different types of outdoor environments, with considerable seasonal variations as well. Conducting comprehensive monitoring of atmospheric aerosol concentrations is very important not only for environmental management but also for the assessment of the health impacts of air pollution. To our knowledge, this is the first study to present outdoor and seasonal changes of bioaerosol data regarding an urban area of Poland. This study aimed to characterize culturable bacteria populations present in outdoor air in Gliwice, Upper Silesia Region, Poland, over the course of four seasons (spring, summer, autumn and winter) through quantification and identification procedures. In this study, the samples of bioaerosol 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). Results showed that the concentration of airborne bacteria ranged from 4 CFU m-3, measured on one winter day, to a maximum equal to 669 CFU m-3 on a spring day. The average size of culturable bacterial aerosol over the study period was 199 CFU m-3. The maximal seasonally averaged concentration was found in the spring season and reached 306 CFU m-3, and the minimal seasonally averaged concentration was found in the winter 49 CFU m-3. The most prevalent bacteria found outdoors were gram-positive rods that form endospores. Statistically, the most important meteorological factors related to the viability of airborne bacteria were temperature and UV radiation. These results may contribute to the promotion and implementation of preventative public health programmes and the formulation of recommendations aimed at providing healthier outdoor environments.

Consideration on the health risk reduction related to attainment of the new particulate matter standards in Poland: A top-down policy risk assessment approach.

Policies can influence health of a population in various ways. Numerous epidemiological studies supported by toxicological investigations demonstrate a positive association between ambient concentrations of airborne particulate matter and increased adverse cardio-respiratory events, including morbidity and mortality. The aim of this paper was to present the concept of the top-down health policy risk assessment approach model developed to estimate the expected health risk reduction associated with policy aiming at attaining the new particulate matter ≤ 10 µm in diameter (PM10) standards in Poland. The top-down approach guides the analysis of causal chains from the policy to health outcomes. In this case study we tried to estimate the predicted health effects of the policy change over the past 20 years. Since Polish annual standard for PM10 changed from 50 µg/m³ in 1990 to 40 µg/m³ in 2010, we calculated the relative risk associated with decreasing PM10 in diameter to 10 µg/m3 in the annual level of PM10 for 6 adverse health effects. The relative risk slightly decreased for almost all adverse health effects, which means that the relative decrease in the incidence of health effects from the baseline incidence should range from about 0.5-0.6% for heart disease admissions to > 1% for respiratory admissions. The obtained results indicate that implementation of the new ambient air standards could influence improvement of the health status of Polish population. A top-down policy health risk assessment model can be one of the main tools in this process, providing harmonized guidance how to seek evidence-based information, which could serve policy-makers.

Mass size distribution and chemical composition of the surface layer of summer and winter airborne particles in Zabrze, Poland.

Mass size distributions of ambient aerosol were measured in Zabrze, a heavily industrialized city of Poland, during a summer and a winter season. The chemical analyses of the surface layer of PM(10), PM(2.5) and PM(1) in this area were also performed by X-ray photoelectron spectroscopy (XPS). Results suggested that the influence of an atmospheric aerosol on the health condition of Zabrze residents can be distinctly stronger in winter than in summer because of both: higher concentration level of particulate matter (PM) and higher contribution of fine particles in winter season compared to summer. In Zabrze in June (summer) PM(10) and PM(2.5) reached about 20 and 14 µg/m(3), respectively, while in December (winter) 57 and 51 µg/m(3), respectively. The XPS analysis showed that elemental carbon is the major surface component of studied airborne particles representing about 78%-80% (atomic mass) of all detected elements.

Characterization of PM10 and PM2.5 and associated heavy metals at the crossroads and urban background site in Zabrze, Upper Silesia, Poland, during the smog episodes.

The concentrations of seven heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, and Pb) associated with PM10 and PM2.5 at the crossroads and the background sites have been studied in Zabrze, Poland, during smog episodes. Although the background level was unusually elevated due to both high particulate emission from the industrial and municipal sources and smog favorable meteorological conditions, significant increase of the concentration of PM2.5 and PM10 as well as associated heavy metals in the roadside air compared to the urban background has been documented. The average daily difference between the roadside and corresponding urban background aerosol concentration was equal to 39.5 microg m(-3) for PM10 and 41.2 microg m(-3) for PM2.5. The highest levels of the studied metals in Zabrze appeared for iron carried by PM10 particles: 1,706 (background) and 28,557 ng m(-3) (crossroads). The lowest concentration level (in PM10) has been found for cadmium: 7 and 77 ng m(-3) in the background and crossroads site, respectively. Also the concentrations of heavy metals carried by the fine particles (PM2.5) were very high in Zabrze during the smog episodes. Concentrations of all studied metals associated with PM10 increased at the roadside compared to the background about ten times (one order) while metals contained in PM2.5 showed two to three times elevated concentrations (except Fe-five times and Cr-no increase).

Emission of airborne fibers from mechanically impacted asbestos-cement sheets and concentration of fibrous aerosol in the home environment in Upper Silesia, Poland.

The emission rate ((S)) of fibers released from asbestos-cement plates due to mechanical impact was determined experimentally. The emission rate has been defined as a number of fibers (F) emitted from a unit area (m(2)) due to the unit impact energy (J). For fiber longer than 5 microm the obtained surface emission factor for asbestos-cement slabs slightly increased with deteriorating surface, changing from 2.7 x 10(3) F/(m(2)J) for samples with a very good surface to 6.9 x 10(3) F/(m(2)J) for the sample with worn surface (in the SI system the emission rate unit should be (m(-2)J(-1))). The emission rate for short fibers (L < or = 5 microm) was little higher compared with emission of long fibers for all studied asbestos materials. The averaged emission rate for all studied samples was about 5000 and 6000 of long and short fibers, respectively, emitted per square meter (because of the impact energy equal to 1J). The dominating population of emitted fibers ranged from 2 to around 8 microm in length. The second part of this work constitutes the report on the concentration of airborne respirable fibers, and their length distribution in two different groups of homes in Upper Silesia, Poland. Mean concentration level of the respirable fibers, longer than 5 microm, was found to be 850 F/m(3) (according to the SI system the fiber concentration unit is (m(-3))) in the buildings covered with asbestos-cement sheets and 280 F/m(3) in the homes without asbestos-containing facades, located away from other asbestos sources. Although the laboratory and field measurements have been made by using the MIE Laser Fiber Monitor FM-7400 only, the obtained results indicate that the outdoor asbestos-cement building facades are significant sources of airborne fibers inside the dwellings in Upper Silesian towns.

Microbial air quality in offices at municipal landfills.

The purpose of this study was to evaluate the influence of two municipal landfills on the microbiological air quality in offices on landfill sites. The evaluation was based on the concentration levels of airborne bacteria and fungi and the identification of isolated strains. Air samples were collected with a six-stage Andersen impactor. The concentrations of bacterial aerosol ranged from 1.0 x 10(3) to 7.2 x 10(4) colony forming units (CFU)/m(3) indoors, and from 7.0 x 10 to 4.0 x 10(4) CFU/m(3) outdoors. The corresponding fungal aerosol ranges were from 2.3 x 10(2) to 7.3 x 10(3) CFU/m(3) indoors and from 2.0 x 10(2) to 1.2 x 10(4) CFU/m(3) outdoors. The concentration levels were affected by the season of the year. The study showed that both indoor and outdoor air were heavily contaminated with bacteria and fungi. The proximity of the unpaved transport route and the weighing of refuse loads contributed to the increase of bacterial and fungal aerosol concentrations significantly. The air in the offices was characterized not only by elevated concentrations of bacteria and fungi but also by high frequencies of gram-negative bacteria, along with fungal species characteristic of landfills. The quantitative and qualitative changes in the composition of the bacterial and fungal aerosol posed a possible health risk to office workers at municipal waste landfill sites.