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4 pages, 214 KiB

Open AccessEditorial

Ambient Air Quality in the Czech Republic

by Iva Hůnová

Atmosphere 2021, 12(6), 770; https://doi.org/10.3390/atmos12060770 - 15 Jun 2021

Cited by 2 | Viewed by 2086

Abstract

Ambient air quality in the present-day Czech Republic (CR), one of the two succession countries of Czechoslovakia post-1993, was perceived as a major problem with severe human health and environmental consequences, particularly between the 1970s and 1990s [...] Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

Research

Jump to: Editorial, Review, Other

27 pages, 20853 KiB

Open AccessArticle

High NO₂ Concentrations Measured by Passive Samplers in Czech Cities: Unresolved Aftermath of Dieselgate?

by Michal Vojtisek-Lom, Miroslav Suta, Jitka Sikorova and Radim J. Sram

Atmosphere 2021, 12(5), 649; https://doi.org/10.3390/atmos12050649 - 19 May 2021

Cited by 5 | Viewed by 4298

Abstract

This work examines the effects of two problematic trends in diesel passenger car emissions—increasing NO₂/NO_x ratio by conversion of NO into NO₂ in catalysts and a disparity between the emission limit and the actual emissions in everyday driving—on ambient [...] Read more.

This work examines the effects of two problematic trends in diesel passenger car emissions—increasing NO₂/NO_x ratio by conversion of NO into NO₂ in catalysts and a disparity between the emission limit and the actual emissions in everyday driving—on ambient air quality in Prague. NO₂ concentrations were measured by 104 membrane-closed Palmes passive samplers at 65 locations in Prague in March–April and September–October of 2019. NO₂ concentrations measured by city stations during those periods were comparable with the average values during 2016–2019. The average measured NO₂ concentrations at the selected locations, after correcting for the 18.5% positive bias of samplers co-located with a monitoring station, were 36 µg/m³ (range 16–69 µg/m³, median 35 µg/m³), with the EU annual limit of 40 µg/m³ exceeded at 32% of locations. The NO₂ concentrations have correlated well (R² = 0.76) with the 2019 average daily vehicle counts, corrected for additional emissions due to uphill travel and intersections. In addition to expected “hot-spots” at busy intersections in the city center, new ones were identified, i.e., along a six-lane road V Holešovičkách. Comparison of data from six monitoring stations during 15 March–30 April 2020 travel restrictions with the same period in 2016–2019 revealed an overall reduction of NO₂ and even a larger reduction of NO. The spatial analysis of data from passive samplers and time analysis of data during the travel restrictions both demonstrate a consistent positive correlation between traffic intensity and NO₂ concentrations along/near the travel path. The slow pace of NO₂ reductions in Prague suggests that stricter vehicle NO_x emission limits, introduced in the last decade or two, have so far failed to sufficiently reduce the ambient NO₂ concentrations, and there is no clear sign of remedy of Dieselgate NO_x excess emissions. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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19 pages, 11825 KiB

Open AccessArticle

Characterization of PM₁₀ Sampled on the Top of a Former Mining Tower by the High-Volume Wind Direction-Dependent Sampler Using INNA

by Irena Pavlíková, Daniel Hladký, Oldřich Motyka, Konstantin N. Vergel, Ludmila P. Strelkova and Margarita S. Shvetsova

Atmosphere 2021, 12(1), 29; https://doi.org/10.3390/atmos12010029 - 28 Dec 2020

Cited by 6 | Viewed by 2497

Abstract

The PM₁₀ concentrations in the studied region (Ostravsko-karvinská agglomeration, Czech Republic) exceed air pollution limit values in the long-term and pose a significant problem for human health, quality of life and the environment. In order to characterize the pollution in the region [...] Read more.

The PM₁₀ concentrations in the studied region (Ostravsko-karvinská agglomeration, Czech Republic) exceed air pollution limit values in the long-term and pose a significant problem for human health, quality of life and the environment. In order to characterize the pollution in the region and identify the pollution origin, Instrumental Neutron Activation Analysis (INAA) was employed for determination of 34 elements in PM₁₀ samples collected at a height of 90 m above ground level. From April 2018 to March 2019, 111 PM₁₀ samples from eight basic wind directions and calm and two smog situations were sampled. The elemental composition significantly varied depending on season and sampling conditions. The contribution of three important industrial sources (iron and steelworks, cement works) was identified, and the long-range cross-border transport representing the pollution from the Polish domestic boilers confirmed the most important pollution inflow during the winter season. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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19 pages, 2646 KiB

Open AccessArticle

Impacts of Built-Up Area Geometry on PM₁₀ Levels: A Case Study in Brno, Czech Republic

by Jiří Neubauer, Jaroslav Michálek, Karel Šilinger and Petr Firbas

Atmosphere 2020, 11(10), 1042; https://doi.org/10.3390/atmos11101042 - 29 Sep 2020

Cited by 1 | Viewed by 2256

Abstract

This paper presents a statistical comparison of parallel hourly measurements of particulate matter smaller than 10

μ

m (PM

_{10}

) from two monitoring stations that are located 560 m from each other in the northern part of Brno City. One monitoring station [...] Read more.

This paper presents a statistical comparison of parallel hourly measurements of particulate matter smaller than 10

μ

m (PM

_{10}

) from two monitoring stations that are located 560 m from each other in the northern part of Brno City. One monitoring station is located in a park, the other in a built-up area. The authors’ aim is to describe the influence of a built-up area geometry and nearby traffic intensity on modeling of PM

_{10}

pollution levels in the respective part of Brno. Furthermore, the purpose of this study is also to examine the influence of meteorological factors on the pollution levels; above all, to assess the influence of wind speed and direction, temperature change, and humidity change. In order to evaluate the obtained data, the following methods of mathematical statistics were applied: descriptive statistics, regression analysis, analysis of variance, and robust statistical tests. According to the results of the Passing–Bablok test, it can be stated that the parallel measurements of PM

_{10}

are significantly different. A regression model for PM

_{10}

pollution prediction was created and tested in terms of applicability; subsequently, it was used in order to compare measurements from both stations. It shows that in addition to the monitored meteorological factors, pollution levels are influenced mainly by traffic intensity and the geometry of the monitored built-up area. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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30 pages, 11631 KiB

Open AccessArticle

Benzo[a]pyrene in the Ambient Air in the Czech Republic: Emission Sources, Current and Long-Term Monitoring Analysis and Human Exposure

by Markéta Schreiberová, Leona Vlasáková, Ondřej Vlček, Jana Šmejdířová, Jan Horálek and Johannes Bieser

Atmosphere 2020, 11(9), 955; https://doi.org/10.3390/atmos11090955 - 7 Sep 2020

Cited by 25 | Viewed by 5532

Abstract

This paper provides a detailed, thorough analysis of air pollution by benzo[a]pyrene (BaP) in the Czech Republic. The Czech residential sector is responsible for more than 98.8% of BaP, based on the national emission inventory. According to the data from 48 sites of [...] Read more.

This paper provides a detailed, thorough analysis of air pollution by benzo[a]pyrene (BaP) in the Czech Republic. The Czech residential sector is responsible for more than 98.8% of BaP, based on the national emission inventory. According to the data from 48 sites of the National Air Quality Monitoring Network, the range of annual average concentration of BaP ranges from 0.4 ng·m⁻³ at a rural regional station to 7.7 ng·m⁻³ at an industrial station. Additionally, short-term campaign measurements in small settlements have recorded high values of daily benzo[a]pyrene concentrations (0.1–13.6 ng·m⁻³) in winter months linked to local heating of household heating. The transboundary contribution to the annual average concentrations of BaP was estimated by the CAMx model to range from 46% to 70% over most of the country. However, the contribution of Czech sources can exceed 80% in residential heating hot spots. It is likely that the transboundary contribution to BaP concentrations was overestimated by a factor of 1.5 due to limitations of the modeling approach used. During the period of 2012–2018, 35–58% of the urban population in the Czech Republic were exposed to BaP concentrations above target. A significant decreasing trend, estimated by the Mann-Kendall test, was found for annual and winter BaP concentrations between 2008 and 2018. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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25 pages, 3610 KiB

Open AccessArticle

Characterization and Source Identification of Elements and Water-Soluble Ions in Submicrometre Aerosols in Brno and Šlapanice (Czech Republic)

by Pavel Mikuška, Martin Vojtěšek, Kamil Křůmal, Martina Mikušková-Čampulová, Jaroslav Michálek and Zbyněk Večeřa

Atmosphere 2020, 11(7), 688; https://doi.org/10.3390/atmos11070688 - 29 Jun 2020

Cited by 14 | Viewed by 2650

Abstract

Submicrometre aerosol particles (particulate matter, PM₁) were collected in two Czech cities (Brno and Šlapanice) during week campaigns in winter and summer of 2009 and 2010. The aerosols were analysed for 14 elements and 12 water-soluble ions using inductively coupled plasma–mass [...] Read more.

Submicrometre aerosol particles (particulate matter, PM₁) were collected in two Czech cities (Brno and Šlapanice) during week campaigns in winter and summer of 2009 and 2010. The aerosols were analysed for 14 elements and 12 water-soluble ions using inductively coupled plasma–mass spectrometry and ion chromatography techniques. The average PM₁ mass concentration was 14.4 and 20.4 µg m⁻³ in Brno and Šlapanice, respectively. Most of the analysed elements and ions exhibit distinct seasonal variability with higher concentrations in winter in comparison to summer. The determined elements and ions together accounted for about 29% of total PM₁ mass, ranging between 16% and 44%. Ion species were the most abundant components in collected aerosols, accounting for 27.2% of mass of PM₁ aerosols, and elements accounted for 1.8% of mass of PM₁ aerosols. One-day backward trajectories were calculated using the Hysplit model to analyse air masses transported towards the sampling sites. The Pearson correlation coefficients between individual PM₁ components and PM₁ mass and air temperature were calculated. To identify the main aerosol sources, factor analysis was applied. Six factors were identified for each locality. The following sources of PM₁ particles were identified in Brno: a municipal incinerator, vehicle exhausts, secondary sulphate, a cement factory, industry and biomass burning. The identified sources in Šlapanice were as follows: a combustion source, coal combustion, a cement factory, a municipal incinerator, vehicle exhausts and industry. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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23 pages, 31551 KiB

Open AccessArticle

High Resolution Air Quality Forecasting over Prague within the URBI PRAGENSI Project: Model Performance during the Winter Period and the Effect of Urban Parameterization on PM

by Jana Ďoubalová, Peter Huszár, Kryštof Eben, Nina Benešová, Michal Belda, Ondřej Vlček, Jan Karlický, Jan Geletič and Tomáš Halenka

Atmosphere 2020, 11(6), 625; https://doi.org/10.3390/atmos11060625 - 12 Jun 2020

Cited by 13 | Viewed by 4270

Abstract

The overall impact of urban environments on the atmosphere is the result of many different nonlinear processes, and their reproduction requires complex modeling approaches. The parameterization of these processes in the models can have large impacts on the model outputs. In this study, [...] Read more.

The overall impact of urban environments on the atmosphere is the result of many different nonlinear processes, and their reproduction requires complex modeling approaches. The parameterization of these processes in the models can have large impacts on the model outputs. In this study, the evaluation of a WRF/Comprehensive Air Quality Model with Extensions (CAMx) forecast modeling system set up for Prague, the Czech Republic, within the project URBI PRAGENSI is presented. To assess the impacts of urban parameterization in WRF, in this case with the BEP+BEM (Building Environment Parameterization linked to Building Energy Model) urban canopy scheme, on Particulate Matter (PM) simulations, a simulation was performed for a winter pollution episode and compared to a non-urbanized run with BULK treatment. The urbanized scheme led to an average increase in temperature at 2 m by 2

^{\circ}

C, a decrease in wind speed by 0.5 m s

^{- 1}

, a decrease in relative humidity by 5%, and an increase in planetary boundary layer height by 100 m. Based on the evaluation against observations, the overall model error was reduced. These impacts were propagated to the modeled PM concentrations, reducing them on average by 15–30

μ

g m

^{- 3}

and 10–15

μ

g m

^{- 3}

for PM

_{10}

and PM

_{2.5}

, respectively. In general, the urban parameterization led to a larger underestimation of the PM values, but yielded a better representation of the diurnal variations. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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26 pages, 5076 KiB

Open AccessArticle

Real-World Exhaust Emissions of Diesel Locomotives and Motorized Railcars during Scheduled Passenger Train Runs on Czech Railroads

by Michal Vojtisek-Lom, Jonáš Jirků and Martin Pechout

Atmosphere 2020, 11(6), 582; https://doi.org/10.3390/atmos11060582 - 2 Jun 2020

Cited by 10 | Viewed by 6170

Abstract

The paper summarizes exhaust emissions measurements on two diesel-electric locomotives and one diesel-hydraulic railcar, each tested for several days during scheduled passenger service. While real driving emissions of buses decrease with fleet turnaround and have been assessed by many studies, there are virtually [...] Read more.

The paper summarizes exhaust emissions measurements on two diesel-electric locomotives and one diesel-hydraulic railcar, each tested for several days during scheduled passenger service. While real driving emissions of buses decrease with fleet turnaround and have been assessed by many studies, there are virtually no realistic emissions data on diesel rail vehicles, many of which are decades old. The engines were fitted with low-power portable online monitoring instruments, including a portable Fourier Transform Infra Red (FTIR) spectrometer, online particle measurement, and in two cases with proportional particle sampling systems, all installed in engine compartments. Due to space constraints and overhead electric traction lines, exhaust flow was computed from engine operating data. Real-world operation was characterized by relatively fast power level transitions during accelerations and interleaved periods of high load and idle, and varied considerably among service type and routes. Spikes in PM emissions during accelerations and storage of PM in the exhaust were observed. Despite all engines approaching the end of their life, the emissions per passenger-km were very low compared to automobiles. Tests were done at very low costs with no disruption of the train service, yielded realistic data, and are also applicable to diesel-hydraulic units, which cannot be tested at standstill. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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9 pages, 2250 KiB

Open AccessArticle

Long-Term Trends of Air Pollution at National Atmospheric Observatory Košetice (ACTRIS, EMEP, GAW)

by Milan Váňa, Adéla Holubová Smejkalová, Jaroslava Svobodová and Pavel Machálek

Atmosphere 2020, 11(5), 537; https://doi.org/10.3390/atmos11050537 - 21 May 2020

Cited by 9 | Viewed by 2887

Abstract

The National Atmospheric Observatory Košetice operated by the Czech Hydrometeorological Institute was established in 1988 as a station specializing in air quality monitoring at the background scale. The observatory is located in the free area outside of the settlement and represents the Czech [...] Read more.

The National Atmospheric Observatory Košetice operated by the Czech Hydrometeorological Institute was established in 1988 as a station specializing in air quality monitoring at the background scale. The observatory is located in the free area outside of the settlement and represents the Czech Republic in various international projects. The objective of the present study is to detect the long-term trends of air quality at the background scale of the Czech Republic. The statistical method used for trend analysis is based on the nonparametric Mann–Kendall test. Generally, the results show that the fundamental drop in emission of basic air pollutants was reflected in the significant decrease in pollution levels. A most significant drop was detected for sulphur. No trend was found for NO₂ in 1990–2012, but a visibly decreasing tendency was registered in the last 7 years. A slightly decreasing trend was registered for O₃ in the whole period, but a slightly increasing tendency was found after 2006. More importantly, the number of episodes exceeding the target value for human health dropped significantly. The reduction of volatile organic compounds (VOCs) emissions was reflected in a statistically significant decrease of concentrations. Only isoprene, which is of natural origin, displays an inverse trend. Concentrations of elemental carbon (EC) and organic carbon (OC) dropped since 2010, but only for EC is the trend statistically significant. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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13 pages, 2483 KiB

Open AccessArticle

Nanoparticle Number Concentration in the Air in Relation to the Time of the Year and Time of the Day

by Jáchym Brzezina, Klaudia Köbölová and Vladimír Adamec

Atmosphere 2020, 11(5), 523; https://doi.org/10.3390/atmos11050523 - 19 May 2020

Cited by 5 | Viewed by 3027

Abstract

The paper analyzes suspended particles number concentrations of 61 size fractions (184 nm to 17,165 nm) in the air at a traffic location. The average course of the individual fractions was analyzed at various intervals – daily, weekly, monthly and annually, in the [...] Read more.

The paper analyzes suspended particles number concentrations of 61 size fractions (184 nm to 17,165 nm) in the air at a traffic location. The average course of the individual fractions was analyzed at various intervals – daily, weekly, monthly and annually, in the period between 2017 and 2019. The data was then used to calculate the arithmetic mean for all the fractions (MS Excel, R) and then using a proprietary web application, heatmaps were constructed. The obtained results showed significant differences in both the annual and daily variation of number concentrations between the individual fractions differing in particle size. In the case of the annual variation, one can see a greater variability of smaller particles, which is most likely due to the source of the actual suspended particles. Meteorological and dispersion conditions are found as important factors for suspended particle concentrations. These can lead to significant differences from year to year. However, a comparison between 2018 and 2019 showed that even though the average absolute number concentrations can differ between years, the actual relative number concentrations, i.e., the ratios between the individual fractions remain very similar. In conclusion it can be said that the difference between the number concentration variation of the size fractions depends on both the actual pollution sources (especially in the long-term, i.e., the annual variation) and the actual size of the particles, which plays a role especially in the short-term (daily, weekly variation). Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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28 pages, 11766 KiB

Open AccessArticle

Air Pollution Sources’ Contribution to PM_2.5 Concentration in the Northeastern Part of the Czech Republic

by Radim Seibert, Irina Nikolova, Vladimíra Volná, Blanka Krejčí and Daniel Hladký

Atmosphere 2020, 11(5), 522; https://doi.org/10.3390/atmos11050522 - 19 May 2020

Cited by 26 | Viewed by 3923

Abstract

This article focuses on the source apportionment of air pollution in a specific northeastern part of the Czech Republic. The research area, located around the city of Třinec, is significantly affected by a complex spectrum of air pollution sources, including local residential heating [...] Read more.

This article focuses on the source apportionment of air pollution in a specific northeastern part of the Czech Republic. The research area, located around the city of Třinec, is significantly affected by a complex spectrum of air pollution sources, including local residential heating (coal and wood burning), heavy industry (mainly iron and steel production), road traffic, and regional and long-range air pollution transport from the nearby cities, Poland, and other countries. The main pollution sources contributing to the total concentration of fine suspended particles (PM_2.5) were evaluated on the basis of the measurements at three sites and on subsequent positive matrix factorization modeling. The six major air pollution factors were identified, and their relative and absolute contributions were quantified. The result of the study is that the most important current task of air protection is to reduce the residential emissions from solid fuels, which are responsible for approximately 50–60% of PM_2.5 concentration, followed by the regional primary and secondary aerosol sources (up to 40% of the total PM_2.5 aerosol mass). Lower contributions have been identified in the case of resuspended mineral and biogenic particles (15–20%), long-range (trans-European) air pollution transport (up to 10%), and heavy industry (up to 10% in the most affected location). A detailed discussion has been provided considering specific regional EC (elemental carbon)–OC (organic carbon) relations in the region with traditional coal-burning for household heating which complicate the interpretation of the PMF (Positive Matrix Factorization) results, especially due to the interference between the traffic, residential heating, and biogenic aerosol factors. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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20 pages, 32414 KiB

Open AccessArticle

Air Quality in Brno City Parks

by Jiří Huzlík, Jitka Hegrová, Karel Effenberger, Roman Ličbinský and Martin Brtnický

Atmosphere 2020, 11(5), 510; https://doi.org/10.3390/atmos11050510 - 15 May 2020

Cited by 7 | Viewed by 3146

Abstract

Parks embody an important element of urban infrastructure and a basic type of public space that shapes the overall character of a city. They form a counterweight to built-up areas and public spaces with paved surfaces. In this context, parks compensate for the [...] Read more.

Parks embody an important element of urban infrastructure and a basic type of public space that shapes the overall character of a city. They form a counterweight to built-up areas and public spaces with paved surfaces. In this context, parks compensate for the lack of natural, open landscapes in cities and thus have a fundamental impact on the quality of life of their inhabitants. For this reason, it is important to consider the quality of the environment in urban parks, air quality in particular. Concentrations of gaseous pollutants, namely, nitric oxide (NO), nitrogen dioxide (NO₂), and ozone (O₃), were measured in parks of Brno, the second-largest city in the Czech Republic. Relevant concentration values of PM₁₀ solids were determined continuously via the nephelometric method, followed by gravimetric method-based validation. The results obtained through the measurement of wind direction, wind speed, temperature, and relative humidity were used to identify potential sources of air pollution in parks. The “openair” and “openairmaps” packages from the OpenSource software R v. 3.6.2 were employed to analyze the effect of meteorological conditions on air pollution. Local polar concentration maps found use in localizing the most serious sources of air pollution within urban parks. The outcomes of the analyses show that the prevailing amount of the pollution determined at the measuring point most likely originates from the crossroads near the sampled localities. At the monitored spots, the maximum concentrations of pollutants are reached especially during the morning rush hour. The detailed time and spatial course of air pollution in the urban parks were indicated in the respective concentration maps capturing individual pollutants. Significantly increased concentrations of nitrogen oxides were established in a locality situated near a busy road (with the traffic intensity of 33,000 vehicles/d); this scenario generally applied to colder weather. The highest PM₁₀ concentrations were measured at the same location and at an average temperature that proved to be the lowest within the entire set of measurements. In the main city park, unlike other localities, higher concentrations of PM₁₀ were measured in warmer weather; such an effect was probably caused by the park being used to host barbecue parties. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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21 pages, 11418 KiB

Open AccessArticle

Detailed Assessment of the Effects of Meteorological Conditions on PM₁₀ Concentrations in the Northeastern Part of the Czech Republic

by Vladimíra Volná and Daniel Hladký

Atmosphere 2020, 11(5), 497; https://doi.org/10.3390/atmos11050497 - 12 May 2020

Cited by 17 | Viewed by 3353

Abstract

This article assessed the links between PM₁₀ pollution and meteorological conditions over the Czech-Polish border area at the Třinec-Kosmos and Věřňovice sites often burdened with high air pollution covering the years 2016–2019. For this purpose, the results of the measurements of special [...] Read more.

This article assessed the links between PM₁₀ pollution and meteorological conditions over the Czech-Polish border area at the Třinec-Kosmos and Věřňovice sites often burdened with high air pollution covering the years 2016–2019. For this purpose, the results of the measurements of special systems (ceilometers) that monitor the atmospheric boundary layer were used in the analysis. Meteorological conditions, including the mixing layer height (MLH), undoubtedly influence the air pollution level. Combinations of meteorological conditions and their influence on PM₁₀ concentrations also vary, depending on the pollution sources of a certain area and the geographical conditions of the monitoring site. Gen1erally, the worst dispersion conditions for the PM₁₀ air pollution level occur at low air temperatures, low wind speed, and low height of the mixing layer along with a wind direction from areas with a higher accumulation of pollution sources. The average PM₁₀ concentrations at temperatures below 1 °C reach the highest values on the occurrence of a mixing layer height of up to 400 m at both sites. The influence of a rising height of the mixing layer at temperatures below 1 °C on the average PM₁₀ concentrations at Třinec-Kosmos site is not as significant as in the case of Věřňovice, where a difference of several tens of µg·m⁻³ in the average PM₁₀ concentrations was observed between levels of up to 200 m and levels of 200–300 m. The average PM₁₀ hourly concentrations at Třinec-Kosmos were the highest at wind speeds of up to 0.5 m·s⁻¹, at MLH levels of up to almost 600 m; at Věřňovice, the influence of wind speeds of up to 2 m·s⁻¹ was detected. Despite the fact that the most frequent PM₁₀ contributions come to the Třinec-Kosmos site from the SE direction, the average maximum concentration contributions come from the W–N sectors at low wind speeds and MLHs of up to 400 m. In Věřňovice, regardless of the prevailing SW wind direction, sources in the NE–E sector from the site have a crucial influence on the air pollution level caused by PM₁₀. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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15 pages, 4192 KiB

Open AccessArticle

Low-Cost Air Quality Sensors: One-Year Field Comparative Measurement of Different Gas Sensors and Particle Counters with Reference Monitors at Tušimice Observatory

by Petra Bauerová, Adriana Šindelářová, Štěpán Rychlík, Zbyněk Novák and Josef Keder

Atmosphere 2020, 11(5), 492; https://doi.org/10.3390/atmos11050492 - 11 May 2020

Cited by 30 | Viewed by 4235

Abstract

With attention increasing regarding the level of air pollution in different metropolitan and industrial areas worldwide, interest in expanding the monitoring networks by low-cost air quality sensors is also increasing. Although the role of these small and affordable sensors is rather supplementary, determination [...] Read more.

With attention increasing regarding the level of air pollution in different metropolitan and industrial areas worldwide, interest in expanding the monitoring networks by low-cost air quality sensors is also increasing. Although the role of these small and affordable sensors is rather supplementary, determination of the measurement uncertainty is one of the main questions of their applicability because there is no certificate for quality assurance of these non-reference technologies. This paper presents the results of almost one-year field testing measurements, when the data from different low-cost sensors (for SO₂, NO₂, O₃, and CO: Cairclip, Envea, FR; for PM₁, PM_2.5, and PM₁₀: PMS7003, Plantower, CHN, and OPC-N2, Alphasense, UK) were compared with co-located reference monitors used within the Czech national ambient air quality monitoring network. The results showed that in addition to the given reduced measurement accuracy of the sensors, the data quality depends on the early detection of defective units and changes caused by the effect of meteorological conditions (effect of air temperature and humidity on gas sensors and effect of air humidity with condensation conditions on particle counters), or by the interference of different pollutants (especially in gas sensors). Comparative measurement is necessary prior to each sensor’s field applications. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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10 pages, 1649 KiB

Open AccessArticle

F-Gases: Trends, Applications and Newly Applied Gases in the Czech Republic

by Markéta Müllerová, Eva Krtková and Zuzana Rošková

Atmosphere 2020, 11(5), 455; https://doi.org/10.3390/atmos11050455 - 30 Apr 2020

Cited by 9 | Viewed by 3612

Abstract

Emissions of fluorinated greenhouse gases (F-gases), which are used as replacements for ozone-depleting substances, have risen sharply since 1995. The rapid increase in F-gas emissions coupled with their global warming potential (GWP) has led to increased worldwide attention to monitoring emission levels and [...] Read more.

Emissions of fluorinated greenhouse gases (F-gases), which are used as replacements for ozone-depleting substances, have risen sharply since 1995. The rapid increase in F-gas emissions coupled with their global warming potential (GWP) has led to increased worldwide attention to monitoring emission levels and subsequently regulating the use of F-gases. These restrictions apply in particular to applications for which alternative technologies are available that are more economically efficient and have minor or no impact on the Earth’s climate system. This paper brings new information about changes in composition of consumed F-gases in the Czech Republic. Since no F-gases are produced in the country, data about F-gas consumption are obtained from three resources which give information about import and export. The paper also describes implementation of newly used F-gases, which are used as replacements for specific F-gases, into emission calculation models. Emissions are estimated according to the methodology developed by the Intergovernmental Panel on Climate Change (IPCC). Although consumption of F-gases with high GWP has already started decreasing, it will have no effect on F-gas emissions for several years. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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15 pages, 3305 KiB

Open AccessArticle

Dispersion Characteristics of PM10 Particles Identified by Numerical Simulation in the Vicinity of Roads Passing through Various Types of Urban Areas

by Jiri Pospisil, Jiri Huzlik, Roman Licbinsky and Michal Spilacek

Atmosphere 2020, 11(5), 454; https://doi.org/10.3390/atmos11050454 - 30 Apr 2020

Cited by 11 | Viewed by 3173

Abstract

The dispersion of particulate matter emitted by road transport to the vicinity of roads is predominantly influenced by the character of the air velocity field. The air flow depends on factors such as the speed and direction of the blowing wind, the movement [...] Read more.

The dispersion of particulate matter emitted by road transport to the vicinity of roads is predominantly influenced by the character of the air velocity field. The air flow depends on factors such as the speed and direction of the blowing wind, the movement of cars, and the geometries of the buildings around a road. Numerical modeling based on the control volume method was used in this study to describe the relevant processes closely. Detailed air velocity fields were identified in the vicinity of a straight road surrounded by various patterns of built-up urban land. The evaluation of the results was generalized to exponential expressions, affecting the decrease of the mass concentration of fine particles with the increasing distance from the road. The obtained characteristics of the mass concentration fields express the impact of the building geometries and configurations on the dispersion of particulate matter into the environment. These characteristics are presented for two wind speeds, namely, 2 m·s⁻¹ and 4 m·s⁻¹. Furthermore, the characteristics are introduced in relation to three wind directions: perpendicularly, obliquely, and in parallel to the road. The results of the numerical simulations are compared with those obtained via the in-situ measurements, for verification of the validity of the linear emission source calculation. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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Review

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26 pages, 15760 KiB

Open AccessReview

Ambient Air Quality in the Czech Republic: Past and Present

by Iva Hůnová

Atmosphere 2020, 11(2), 214; https://doi.org/10.3390/atmos11020214 - 20 Feb 2020

Cited by 54 | Viewed by 11181

Abstract

Based on an analysis of related core papers and reports, this review presents a historical perspective on ambient air pollution and ambient air quality development in the modern-day Czech Republic (CR) over the past seven decades, i.e., from the 1950s to the present. [...] Read more.

Based on an analysis of related core papers and reports, this review presents a historical perspective on ambient air pollution and ambient air quality development in the modern-day Czech Republic (CR) over the past seven decades, i.e., from the 1950s to the present. It offers insights into major air pollution problems, reveals the main hot spots and problematic regions and indicates the principal air pollutants in the CR. Air pollution is not presented as a stand-alone problem, but in the wider context of air pollution impacts both on human health and the environment in the CR. The review is arranged into three main parts: (1) the time period until the Velvet Revolution of 1989, (2) the transition period of the 1990s and (3) the modern period after 2000. Obviously, a major improvement in ambient air quality has been achieved since the 1970s and 1980s, when air pollution in the former Czechoslovakia culminated. Nevertheless, new challenges including fine aerosol, benzo[a]pyrene and ground-level ozone, of which the limit values are still vastly exceeded, have emerged. Furthermore, in spite of a significant reduction in overall emissions, the atmospheric deposition of nitrogen, in particular, remains high in some regions. Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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Other

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1 pages, 175 KiB

Open AccessErratum

Erratum: Hůnová, I. Ambient Air Quality in the Czech Republic: Past and Present. Atmosphere 2020, 11, 214

by Iva Hůnová

Atmosphere 2021, 12(6), 720; https://doi.org/10.3390/atmos12060720 - 4 Jun 2021

Cited by 2 | Viewed by 1814

Abstract

Text Correction [...] Full article

(This article belongs to the Special Issue Ambient Air Quality in the Czech Republic)

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