Evaluation of Fine and Ultrafine Particles Proportion in Airborne Dust in an Industrial Area.

The health impacts of suspended particulate matter (SPM) are significantly associated with size-the smaller the aerosol particles, the stronger the biological effect. Quantitative evaluation of fine and ultrafine particles (FP and UFP) is, therefore, an integral part of ongoing epidemiological studies. The mass concentrations of SPM fractions (especially PM2.5, PM1.0, PM0.25) were measured in an industrial area using cascade personal samplers and a gravimetric method, and their mass ratio was determined. The results of PM2.5, PM1.0 were also compared with the reference measurement at stationary stations. The mean ratios PM2.5/SPM, PM1.0/SPM, and PM1.0/PM2.5 were 0.76, 0.65, and 0.86, respectively. Surprisingly, a mass dominance of UFP with an aerodynamic diameter <0.25 µm (PM0.25) was found with mean ratios of 0.43, 0.57, 0.67 in SPM, PM2.5 and PM1.0. The method used showed satisfactory agreement in comparison with reference measurements. The respirable fraction may consist predominantly of UFP. Despite the measures currently being taken to improve air quality, the most biologically efficient UFP can escape and remain in the air. UFP are currently determined primarily as particle number as opposed to the mass concentration used for conventional fractions. This complicates their mutual comparison and determination of individual fraction ratios.

Associations between air pollution in the industrial and suburban parts of Ostrava city and their use.

Selecting the locations and numbers of air quality monitoring stations is challenging as these are expensive to operate. Representative concentrations of pollutants in certain areas are usually determined by measuring. If there are significant correlations with concentrations of other pollutants or with other monitoring sites, however, concentrations could also be computed, partly reducing the costs. The aim of this study is to provide an overview of such possible relationships using data on concentrations of ambient air pollutants obtained in different areas of a larger city. Presented are associations between industrial (IP) and suburban parts (SP) as well as correlations between concentrations of various pollutants at the same site. Results of air pollutant monitoring come from Ostrava, an industrial city in Central Europe with a population of over 300,000. The study showed that certain pollutants were strongly correlated, especially particulate matter (r = 0.940) and ozone (r = 0.923) between the IP and SP. Statistically significant correlations were also found between different pollutants at the same site. The highest correlations were between PM10 and NO2 (r IP = 0.728; r SP = 0.734), NO2 and benzo(a)pyrene (r IP = 0.787; r SP = 0.697), and NO2 and ozone (r IP = -0.706; r SP = -0.686). This could contribute to more cost-effective solutions for air pollution monitoring in cities and their surroundings by using computational models based on the correlations, optimization of the network of monitoring stations, and the best selection of measuring devices.

Air Pollution and Potential Health Risk in Ostrava Region - a Review.

AIM: The aim of this review was to collect all available data about air pollution in Ostrava, which is one of the most polluted area in central Europe and to make a concise assessment of health risks resulting from historical exposures of air pollutants since the beginning of the monitoring, i.e. since 1970 to the present time. METHODS: All available information sources (the Czech Hydrometeorological Institute, the Institute of Public Health in Ostrava or publications) were used. To evaluate the exposures both short-term (hourly and daily) data and long term (yearly) data during 45 years were analysed. For health risk assessment the relationship between exposure and biological effects of pollutants published by the WHO and the US EPA were employed. RESULTS: During the studied period annual average concentrations of PM10 ranged from 25 to 96 µg/m3; PM2.5 from 24 to 45 µg/m3; SO2 from 3.4 to 101.5 µg/m3; NO2 from 17.76 to 51.17 µg/m3; benzene from 0.24 to 9.2 µg/m3; benzo[a]pyrene from 2.1 to 14 ng/m3; arsenic from 1.2 to 9.5 ng/m3. Since the turn of the 80s and 90s of the 20th century trend of air pollutant concentrations has been decreasing until the turn of millennium, when it stopped, and it has been constant until present time. However, presented results demonstrate that the citizens of Ostrava have been exposed to relatively high concentrations of pollutants in comparison to other similar cities. The most significant pollutants contributing to health risks are airborne dust (PM10, PM2.5), benzene and benzo[a]pyrene. The long-term average health risk of PM10 has increased in case of postneonatal infant mortality up to 30%; prevalence of bronchitis in children up to 61%; and incidence of chronic bronchitis in adults up to 89%. The long-term average health risk of PM2.5 increased for all-cause mortality in persons aged 30+ years up to 22%; cardiopulmonary related mortality up to 25%; and lung cancer related mortality up to 39%. The highest carcinogenic risk is observed in benzo[a]pyrene, when the range of individual lifetime carcinogenic risk is up to 1.25*10-3. This assessment is valid according to the strict carcinogenic risk by the WHO, while the maximum carcinogenic risk according the US EPA is 7.2*10-5. CONCLUSIONS: A significant reduction of the pollutants' concentrations in Ostrava in the nineties of the last century does not mean a required improvement of outdoor air quality to the desired level. Persisting episodes with a very strong short-term increase of the concentration of PM10 and PM2.5, as well as long-term load of these substances on the population is very high. Health risks from such burdens are likely to lead to a higher mortality and morbidity especially from specific diseases.

Bioaerosols in the Suburbs of Ostrava during a One Year Period.

AIM: The aim of this paper is to provide information about the concentrations of airborne bioaerosols (airborne bacteria, fungi and endotoxins) in outdoor suburban environments in Ostrava, Moravian-Silesian region, Czech Republic. METHODS: The methods were based on systematic bioaerosol monitoring during one calendar year, subsequent analysis of the samples and statistical processing. The regression, correlation analysis and analysis of variance for one factor and pairwise comparisons were performed on bioaerosol data to determine their dependence on season, daytime, temperature, humidity and dew point. RESULTS: The results show higher fungi concentrations especially in summer (corrected mean 365 colony forming units - CFU per m3) compared to other seasons (75-209 CFU/m3) and higher concentrations of bacteria in the evening (380 CFU/m3) compared to other parts of the day and seasons (in summer 206-252 CFU/m3 and in winter 81-87 CFU/m3). Concentrations of endotoxins were relatively low throughout the year, on average 0,056 endotoxin units (EU) per m3. CONCLUSIONS: The concentration of bioaerosol (bacteria, fungi and endotoxins) were found in ambient air at substantially lower levels than in an indoor environment. Although the concentrations of this bioaerosol greatly fluctuate with temperature, dew point, season and daytime, they do not represent increased health risks.