The influence of local emissions and regional air pollution transport on a European air pollution hot spot

Can air pollution reduce technology transfer? Evidence from China's prefecture-level cities

Air pollution hinders technological innovation, but the causal effects of air pollution on technology transfer are overlooked. We use thermal inversion as an instrumental variable for addressing air pollution endogeneity. The empirical results show that a one-unit increase in air pollution reduces technology transfer strength by 4.5 %. However, air pollution has a strong asymmetry in two directions of technology transfer strength. We find that those cities with worse pollution have an intention to transfer their technologies to cities in other provinces. In the PLFC model, heterogeneity varying with GDP can be addressed to estimate the marginal effect between them. Findings suggest that the marginal effects of air pollution on technology transfer can be divided into two parts based on GDP levels. Within the thresholds (lngdp = 11), the effect of environmental regulations will keep increasing and keep stable beyond the thresholds. In addition, different effects on different cities are also discussed.

Atmospheric Deposition of Benzo[a]pyrene: Developing a Spatial Pattern at a National Scale

Benzo[a]pyrene (BaP), an indicator of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere, is an important ambient air pollutant with significant human health and environmental effects. In the Czech Republic (CR), BaP, together with aerosol and ambient ozone, ranks (with respect to limit value exceedances and resulting population exposure) among the most problematic air pollutants. The aim of this study is to develop atmospheric deposition patterns of BaP in three years, namely 2012, 2015 and 2019, reflecting different BaP ambient levels. With respect to the available measurements, we accounted for dry deposition fluxes, neglecting wet contribution. We assumed, nevertheless, that the real atmospheric deposition is dominated by dry pathways in our conditions, which is supported by measurements from the rural site of Košetice. The dry deposition spatial pattern was constructed using an inferential approach, with two input layers, i.e., annual mean ambient air BaP concentrations, and deposition velocity of 0.89 cm·s−1. Though our results show an overall decrease in BaP loads over the years, the BaP deposition fluxes, in particular in the broader Ostrava region, remain very high. The presented maps can be considered an acceptable approximation of total BaP deposition and are useful for further detailed analysis of airborne BaP impacts on the environment.

Meteorological mechanism of regional PM2.5 transport building a receptor region for heavy air pollution over Central China

Regional transport of air pollutants is a key factor affecting air quality over the receptor region, where the meteorological mechanism of regional transport influence has not been fully understood. The Twain-Hu Basin (THB) in central China is located in the downwind area of major pollutant sources over central and eastern China (CEC) under the East Asian winter monsoonal winds. To understand the meteorological mechanism of regional PM_2.5 transport building a receptor region for heavy air pollution, an ensemble of 8 typical heavy air pollution events with regional PM_2.5 transport in January of 2015-2019 were selected objectively by using the MV-EOF (multivariable empirical orthogonal function) decomposition with multi-source observations, and the meteorological configurations driving the regional PM_2.5 transport and building a receptor in the THB with heavy air pollution were investigated. The results showed that PM_2.5 from the source area in northern China to the THB was actuated by cold air southward invasion with strong northerly winds in the lower troposphere, and the vertical structure of atmospheric circulation was characterized with the typical pattern of southward advance of cold front with the cold air confronting the warm air mass over the THB area. The warm air mass and the windward side of THB's basin terrain formed a "barrier" in regional transport of PM_2.5 over central China, which were conducive to accumulating PM_2.5 for heavy air pollution in the THB. Furthermore, an abnormal warm air layer in the middle troposphere acted as the upper "warm lid", suppressing the vertical PM_2.5 diffusion over the receptor region. With such the 3-D atmospheric structure, a key receptor region in the THB for heavy air pollution was built in regional PM_2.5 transport over China. These findings could enrich the scientific understanding of the meteorological mechanism on air pollution with regional transport of source-receptor air pollutants in atmospheric environment change.

Transboundary Air Pollution Transport of PM10 and Benzo[a]pyrene in the Czech–Polish Border Region

The article is occupied with the evaluation of the transboundary transport of pollutants in the Czech–Polish border region (between the Moravian-Silesian region and the Silesian Voivodeship) in Central Europe. It focuses on the evaluation of concentrations of benzo[a]pyrene (BaP) and suspended particles of PM10 depending on meteorological conditions, especially wind direction. The whole area of interest is heavily affected with air pollution of BaP and PM10. Limits of BaP and PM10 are still exceeded. Annual concentrations of benzo[a]pyrene are even several times higher than the value of its annual limit. The elaboration follows the results of the Czech–Polish project “Air Silesia”, which dealt with air pollution and the transboundary transport of pollutants in this area and took place in 2010 to 2013. Within this project, a higher transport of pollutants from Poland to the Czech Republic was established. The evaluation of the dependences of PM10 concentrations is based on hourly and daily data of PM10 and hourly data of meteorological quantities. To assess the dependences of daily BaP and PM10 concentrations, a methodology for evaluating daily types of wind direction was implemented into the processing. The results confirm that the problem of above-limit concentrations of BaP and PM10 in the Moravian-Silesian Region in the Czech Republic and the Silesian Voivodeship in Poland remains. The article confirms there is a higher transport of PM10 concentrations from Poland to the Czech Republic in the area of interest. Higher transport in the same direction is also predicted for daily concentrations of benzo[a]pyrene, although this cannot be clearly confirmed due to the lack of more detailed and identifiable data.

Seasonal changes in stable carbon isotopic composition in the bulk aerosol and gas phases at a suburban site in Prague

Isotope fractionation between the gas and aerosol phases is an important phenomenon for studying atmospheric processes. Here, for the first time, seasonally resolved stable carbon isotope ratio (δ¹³C) values are systematically used to study phase interactions in bulk aerosol and gaseous carbonaceous samples. Seasonal variations in the δ¹³C of total carbon (TC; δ¹³C_TC) and water-soluble organic carbon (WSOC; δ¹³C_WSOC) in fine aerosol particles (PM_2.5) as well as in the total carbon of part of the gas phase (TCgas; δ¹³C_TCgas) were studied at a suburban site in Prague, Czech Republic, Central Europe. Year-round samples were collected for the main and backup filters from 14 April 2016 to 1 May 2017 every 6 days with a 48 h sampling period (n = 66). During all seasons, the highest ¹³C enrichment was found in WSOC, followed by particulate TC, whereas the highest ¹³C depletion was found in gaseous TC. We observed a clear seasonal pattern for all δ¹³C, with the highest values in winter (avg. δ¹³C_TC = -25.5 ± 0.8‰, δ¹³C_WSOC = -25.0 ± 0.7‰, δ¹³C_TCgas = -27.7 ± 0.5‰) and the lowest values in summer (avg. δ¹³C_TC = -27.2 ± 0.5‰, δ¹³C_WSOC = -26.4 ± 0.3‰, δ¹³C_TCgas = -28.9 ± 0.3‰). This study supports the existence of different aerosol sources at the site during the year. Despite the different seasonal compositions of carbonaceous aerosols, the isotope difference (Δδ¹³C) between δ¹³C_TC (aerosol) and δ¹³C_TCgas (gas phase) was similar during the seasons (year avg. 1.97 ± 0.50‰). Moreover, Δδ¹³C between WSOC and TC in PM_2.5 showed a difference between spring and winter, but in general, these values were also similar year-round (year avg. 0.71 ± 0.37‰). During the entire period, TCgas and WSOC were the most ¹³C-depleted and most ¹³C-enriched fractions, respectively, and although the resulting difference Δ(δ¹³C_WSOC - δ¹³C_TCgas) was significant, it was almost invariant throughout the year (2.67 ± 0.44‰). The present study suggests that the stable carbon isotopic fractionation between the bulk aerosol and gas phases is probably not entirely dependent on the chemical composition of individual carbonaceous compounds from different sources.

Persistent pollution episodes, transport pathways, and potential sources of air pollution during the heating season of 2016-2017 in Lanzhou, China

As one of the most important industrial cities in Northwest China, Lanzhou currently suffers from serious air pollution. This study analyzed the formation mechanism and potential source areas of persistent air pollution in Lanzhou during the heating period from November 1, 2016 to March 31, 2017 based on the air pollutant concentrations and relevant meteorological data. Our findings indicate that particulate pollution was extremely severe during the study period. The daily PM_2.5 and PM₁₀ concentrations had significantly negative correlations with daily temperature, wind speed, maximum daily boundary layer height, while the daily PM_2.5 and PM₁₀ concentrations showed significantly positive correlations with daily relative humidity. Five persistent pollution episodes were identified and classified as either stagnant accumulation or explosive growth types according to the mechanism of pollution formation and evolution. The PM_2.5 and PM₁₀ concentrations and PM_2.5/PM₁₀ ratio followed a growing "saw-tooth cycle" pattern during the stagnant accumulation type event. Dust storms caused abrupt peaks in PM₁₀ and a sharp decrease in the PM_2.5/PM₁₀ ratio in explosive growth type events. The potential sources of PM₁₀ were mainly distributed in the Kumtag Desert in Xinjiang Uygur Autonomous Region, the Qaidam Basin and Hehuang Valley in Qinghai Province, and the western and eastern Hexi Corridor in Gansu Province. The contributions to PM₁₀ were more than 120 μg/m³. The important potential sources of PM_2.5 were located in Hehuang Valley in Qinghai and Linxia Hui Autonomous Prefecture in Gansu; the concentrations of PM_2.5 were more than 60 μg/m³.

Nitrated monoaromatic hydrocarbons (nitrophenols, nitrocatechols, nitrosalicylic acids) in ambient air: levels, mass size distributions and inhalation bioaccessibility

Nitrated monoaromatic hydrocarbons (NMAHs) are ubiquitous in the environment and an important part of atmospheric humic-like substances (HULIS) and brown carbon. They are ecotoxic and with underresearched toxic potential for humans. NMAHs were determined in size-segregated ambient particulate matter collected at two urban sites in central Europe, Ostrava and Kladno, Czech Republic. The average sums of 12 NMAHs (Σ₁₂NMAH) measured in winter PM₁₀ samples from Ostrava and Kladno were 102 and 93 ng m^-3, respectively, and 8.8 ng m^-3 in summer PM₁₀ samples from Ostrava. The concentrations in winter corresponded to 6.3-7.3% and 2.6-3.1% of HULIS-C and water-soluble organic carbon (WSOC), respectively. Nitrocatechols represented 67-93%, 61-73% and 28-96% of NMAHs in PM₁₀ samples collected in winter and summer at Ostrava and in winter at Kladno, respectively. The mass size distribution of the targeted substance classes peaked in the submicrometre size fractions (PM₁), often in the PM_0.5 size fraction especially in summer. The bioaccessible fraction of NMAHs was determined by leaching PM₃ samples in two simulated lung fluids, Gamble's solution and artificial lysosomal fluid (ALF). More than half of NMAH mass is found bioaccessible, almost complete for nitrosalicylic acids. The bioaccessible fraction was generally higher when using ALF (mimics the chemical environment created by macrophage activity, pH 4.5) than Gamble's solution (pH 7.4). Bioaccessibility may be negligible for lipophilic substances (i.e. log K_OW > 4.5).

Modelling the Interaction between Air Pollutant Emissions and Their Key Sources in Poland

The main purpose of this study is to investigate the relationships between key sources of air pollutant emissions (sources of energy production, factories which are particularly harmful to the environment, the fleets of cars, environmental protection expenditure) and the main environmental air pollution (SO2, NOx, CO and PM) in Poland. Models based on MLP neural networks were used as predictive models. Global sensitivity analysis was used to demonstrate the significant impact of individual network input variables on the output variable. To verify the effectiveness of the models created, the actual data were compared with the data obtained through modelling. Projected courses of changes in the variables under study correspond with the real data, which confirms that the proposed models generalize acquired knowledge well. The high MLP network quality parameters of 0.99–0.85 indicate that the network generalizes the acquired knowledge accurately. The sensitivity analysis for NOx, CO and PM pollutants indicates the significance of all input variables. For SO2, it showed significance for four of the six variables analysed. The predictions made by the neural models are not very different from the experimental values.

How far climatic parameters associated with air quality induced risk state (AQiRS) during COVID-19 persuaded lockdown in India

Global temperature rises in response to accumulating greenhouse gases is a well-debated issue in the present time. Historical records show that greenhouse gases positively influence temperature. Lockdown incident has brought an opportunity to justify the relation between greenhouse gas centric air pollutants and climatic variables considering a concise period. The present work has intended to explore the trend of air quality parameters, and air quality induced risk state since pre to during the lockdown period in reference to India and justifies the influence of pollutant parameters on climatic variables. Results showed that after implementation of lockdown, about 70% area experienced air quality improvement during the lockdown. The hazardous area was reduced from 7.52% to 5.17%. The spatial association between air quality components and climatic variables were not found very strong in all the cases. Still, statistically, a significant relation was observed in the case of surface pressure and moisture. From this, it can be stated that pollutant components can control the climatic components. This study recommends that pollution source management could be a partially good step for bringing climatic resilience of a region.

Spatial-temporal variability of aerosol sources based on chemical composition and particle number size distributions in an urban settlement influenced by metallurgical industry

The Moravian-Silesian region of the Czech Republic with its capital city Ostrava is a European air pollution hot spot for airborne particulate matter (PM). Therefore, the spatiotemporal variability assessment of source contributions to aerosol particles is essential for the successful abatement strategies implementation. Positive Matrix Factorization (PMF) was applied to highly-time resolved PM_0.15-1.15 chemical composition (1 h resolution) and particle number size distribution (PNSD, 14 nm - 10 μm) data measured at the suburban (Ostrava-Plesná) and urban (Ostrava-Radvanice) residential receptor sites in parallel during an intensive winter campaign. Diel patterns, meteorological variables, inorganic and organic markers, and associations between the chemical composition factors and PNSD factors were used to identify the pollution sources and their origins (local, urban agglomeration and regional). The source apportionment analysis resolved six and four PM_0.15-1.15 sources in Plesná and Radvanice, respectively. In Plesná, local residential combustion sources (coal and biomass combustion) followed by regional combustion sources (residential heating, metallurgical industry) were the main contributors to PM_0.15-1.15. In Radvanice, local residential combustion and the metallurgical industry were the most important PM_0.15-1.15 sources. Aitken and accumulation mode particles emitted by local residential combustion sources along with common urban sources (residential heating, industry and traffic) were the main contributors to the particle number concentration (PNC) in Plesná. Additionally, accumulation mode particles from local residential combustion sources and regional pollution dominated the particle volume concentration (PVC). In Radvanice, local industrial sources were the major contributors to PNC and local coal combustion was the main contributor to PVC. The source apportionment results from the complementary datasets elucidated the relevance of highly time-resolved parallel measurements at both receptor sites given the specific meteorological conditions produced by the regional orography. These results are in agreement with our previous studies conducted at this site. Graphical abstract.

Pollution characteristics of bioaerosols in PM2.5 during the winter heating season in a coastal city of northern China

Frequent heavy air pollution occurred during the winter heating season of northern China. In this study, PM_2.5 (particles with an aerodynamic diameter less than 2.5 μm) was collected from a coastal city of China during the winter heating season from January 1 to March 31, 2018, and the soluble ions, organic carbon (OC), elemental carbon (EC), bacterial, endotoxin, and fungal concentration in PM_2.5 were analyzed. During the winter heating season, PM_2.5 and bioaerosols increased on polluted days, and the secondary inorganic ions, including NO₃^-, NH₄⁺, and SO₄^2-, increased significantly. Meteorological factors, such as wind direction and wind speed, had major impacts on the distributions of PM_2.5 and bioaerosols. Pollutant concentration was high when there was a westerly wind with the speed of 3-6 m/s from inland area. Using the air mass backward trajectories and principal component analysis, we elucidate the potential origins of bioaerosol in PM_2.5. The backward trajectory suggested that air mass for polluted samples (PM_2.5 > 75 μg/m³) commonly originated from continent (9.62%), whereas air masses for clean samples (PM_2.5 < 35 μg/m³) were mainly from marine (56.73%). The interregional transport of pollutants from continental area contributed most to PM_2.5. Principal component analysis of the water-soluble ions and bioaerosol indicated that air pollution of the coastal city was greatly affected by coal combustion, biomass burning, and regional transmission of high-intensity pollutants from continent. Among that, interregional transport, biomass burning, and dust from soil and plants were main sources of bioaerosol. Our findings provide important insights into the origins and characteristics of bioaerosol in PM_2.5 during the winter heating season of the coastal city in northern China.

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

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.

Air Pollution Sources’ Contribution to PM2.5 Concentration in the Northeastern Part of the Czech Republic

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 (PM2.5) 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 PM2.5 concentration, followed by the regional primary and secondary aerosol sources (up to 40% of the total PM2.5 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.

Concentration Variability of Water-Soluble Ions during the Acceptable and Exceeded Pollution in an Industrial Region

This study investigates the chemical composition of water-soluble inorganic ions at eight localities situated in the Moravian-Silesian Region (the Czech Republic) at the border with Poland. Water-soluble inorganic ions were monitored in the winter period of 2018 (January, 11 days and February, 5 days). The set was divided into two periods: the acceptable period (the 24-h concentration of PM₁₀ < 50 µg/m³) and the period with exceeded pollution (PM₁₀ ˃ 50 µg/m³). Air quality in the Moravian-Silesian Region and Upper Silesia is among the most polluted in Europe, especially in the winter season when the concentration of PM₁₀ is repeatedly exceeded. The information on the occurrence and behaviour of water-soluble inorganic ions in the air during the smog episodes in Europe is insufficient. The concentrations of water-soluble ions (chlorides, sulphates, nitrates, ammonium ions, potassium) during the exceeded period are higher by two to three times compared with the acceptable period. The major anions for both acceptable period and exceeded pollution are nitrates. During the period of exceeded pollution, percentages of water-soluble ions in PM₁₀ decrease while percentages of carbonaceous matter and insoluble particles (fly ash) increase.

Living Environment Quality Determinants, Including PM2.5 and PM10 Dust Pollution in the Context of Spatial Issues—The Case of Radzionków

This article discusses living environment determinants in Central and Eastern Europe. It is based on a case study of the city of Radzionków, which has 16 thousand inhabitants and is located in the Silesian agglomeration in southern Poland. Hard coal has been mined in this area for almost two hundred years, and it is the main fuel used for central heating. A total of 360 buildings, divided into groups of 60 buildings each, were investigated in the selected city. Three distinct areas were distinguished in terms of living environment quality, depending on building technical condition, heating method and location. These qualities were found to be largely determined by site-specific spatial and geophysical conditions. A significant portion of the literature was found to ignore the spatial factors mentioned in this paper, instead focusing primarily on statistical data concerning pollution. This study examines site-specific variables and presents differences in air pollution levels as examined in relation to the morphological structure of development, the degree of building modernisation and heating system types.

Oxygenated and Nitrated Polycyclic Aromatic Hydrocarbons in Ambient Air-Levels, Phase Partitioning, Mass Size Distributions, and Inhalation Bioaccessibility

Among the nitrated and oxygenated polycyclic aromatic hydrocarbons (NPAHs and OPAHs) are some of the most hazardous substances to public health, mainly because of their carcinogenicity and oxidative potential. Despite these concerns, the concentrations and fate of NPAHs and OPAHs in the atmospheric environment are largely unknown. Ambient air concentrations of 18 NPAHs, 5 quinones, and 5 other OPAHs were determined at two urban and one regional background sites in central Europe. At one of the urban sites, the total (gas and particulate) concentrations of Σ10OPAHs were 10.0 ± 9.2 ng/m3 in winter and 3.5 ± 1.6 ng/m3 in summer. The gradient to the regional background site exceeded 1 order of magnitude. Σ18NPAH concentrations were typically 1 order of magnitude lower than OPAHs. Among OPAHs, 9-fluorenone and (9,10)-anthraquinone were the most abundant species, accompanied by benzanthrone in winter. (9,10)-Anthraquinone represented two-thirds of quinones. We found that a large fraction of the target substance particulate mass was carried by submicrometer particles. The derived inhalation bioaccessibility in the PM10 size fraction is found to be ≈5% of the total ambient concentration of OPAHs and up to ≈2% for NPAHs. For 9-fluorenone and (9,10)-anthraquinone, up to 86 and 18%, respectively, were found at the rural site. Our results indicate that water solubility could function as a limiting factor for bioaccessibility of inhaled particulate NPAHs and OPAHs, without considerable effect of surfactant lipids and proteins in the lung lining fluid.

Ambient Air Quality in the Czech Republic: Past and Present

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.

Evaluate Air Pollution by Promethee Ranking in Yangtze River Delta of China

A series of problems that are related to population, resources, environment, and ecology have emerged in recent years with the advancement of industrialization and urbanization in China. Especially, air pollution has become a severe trouble that directly endangers the health of residents. Accordingly, it is a need to make the assessment of air quality among cities, so that corresponding measures can be taken. For this purpose, ten major cities are selected as the research objects in Yangtze River Delta. Additionally, this study gathers and processes the data of five main air pollutants PM_2.5, PM₁₀, SO₂, O₃, and NO₂, respectively. Furthermore, the maximizing deviation method is used to obtain the respective weight of these pollutants and the preference ranking organization method for enrichment evaluations (PROMETHEE) is introduced into the assessment of air quality among ten cities. As a result, the ranking of air quality in Ningbo, Wenzhou, Shanghai, and Shaoxing was at the fore from 2014 to 2017. Meanwhile, the performance of Ningbo has always kept the top two and Shaoxing’s ranking has risen since 2015. In addition, the air quality of Changzhou, Suzhou and Hangzhou was at an average level in the past four years. Moreover, the performance of Nanjing, Wuxi, and Zhenjiang was terrible when compared to other cities. Some useful suggestions have been proposed to control air quality based on the ranking results.

Trace elements and human health risks assessment of finer aerosol atmospheric particles (PM1)

The present study investigated PM₁ (aerosol particles with an aerodynamic diameter ≤ 1.0 μm) mass concentrations and sixteen (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, S, Ti, and Zn) PM₁-related trace elements. PM₁ samples were collected in an anthropized area of international attention close to oil/gas pre-treatment plants in Agri Valley (Southern Italy). The PM₁ mass concentrations varied from 3 to 16 μg/m³. The decreasing pattern of the trace element concentrations was S > Ca > Na > K ≈ Mg ≈ Fe> Al > Li > Cr > Zn > Ti> Cu > Ni ≈ Mn > Pb ≈ Cd. Anthropogenic local emissions such as biomass burning, vehicular traffic, and industrial sources mainly related to oil/gas pre-treatment plants were identified by the principal component analysis. Further, air mass back-trajectory analyses suggest an important contribute to the long-range transport on PM₁ at Agri Valley. The carcinogenic (Cd, Cr(VI), Ni, and Pb) and non-carcinogenic (Cd, Cr(VI), Cu, Mn, Ni, Pb, and Zn) health risks both for children and for adults were assessed using the United State Environmental Protection Agency (USEPA) methods considering inhalation, ingestion, and dermal contact pathway. Chromium (VI) posed the highest carcinogenic risk for both children and adults. The integrated carcinogenic risks were respectively 3.45 × 10^-5 and 1.38 × 10^-4 for children and adults indicating that attention should be paid for carcinogenic health effects. Nickel posed the highest non-carcinogenic risk for children through inhalation pathway. The integrated non-carcinogenic risk showed a value higher than 1 highlighting that Cd, Cr(VI), Cu, Mn, Ni, Pb, and Zn may cause cumulative non-carcinogenic health effect for children from inhalation exposure.

Concomitant occurrence of anthropogenic air pollutants, mineral dust and fungal spores during long-distance transport of ragweed pollen

Large-scale synoptic conditions are able to transport considerable amounts of airborne particles over entire continents by creating substantial air mass movement. This phenomenon is observed in Europe in relation to highly allergenic ragweed (Ambrosia L.) pollen grains that are transported from populations in Central Europe (mainly the Pannonian Plain and Balkans) to the North. The path taken by atmospheric ragweed pollen often passes through the highly industrialised mining region of Silesia in Southern Poland, considered to be one of the most polluted areas in the EU. It is hypothesized that chemical air pollutants released over Silesia could become mixed with biological material and be transported to less polluted regions further North. We analysed levels of air pollution during episodes of long-distance transport (LDT) of ragweed pollen to Poland. Results show that, concomitantly with pollen, the concentration of air pollutants with potential health-risk, i.e. SO₂, and PM₁₀, have also significantly increased (by 104% and 37%, respectively) in the receptor area (Western Poland). Chemical transport modelling (EMEP) and air mass back-trajectory analysis (HYSPLIT) showed that potential sources of PM₁₀ include Silesia, as well as mineral dust from the Ukrainian steppe and the Sahara Desert. In addition, atmospheric concentrations of other allergenic biological particles, i.e. Alternaria Nees ex Fr. spores, also increased markedly (by 115%) during LDT episodes. We suggest that the LDT episodes of ragweed pollen over Europe are not a "one-component" phenomenon, but are often related to elevated levels of chemical air pollutants and other biotic and abiotic components (fungal spores and desert dust).

Development of Renewable Energy Sources in the Context of Threats Resulting from Low-Altitude Emissions in Rural Areas in Poland: A Review

The process of transformation of the Polish economy, traditionally based on coal, into an economy that uses low-carbon technologies, faces a problem associated with the diversification of energy sources, especially in rural areas. The scale of the use of conventional energy carriers in households located in rural areas in Poland has a very negative impact on the natural environment. The aim of the paper is to indicate possibilities of reducing low-altitude emissions (with emitters not exceeding 40 m in height) in rural areas in Poland, through the development of renewable energy sources. This paper provides an overview of the specific character of rural areas in Poland and the development challenges faced in these areas in the investigated scope. In order to reduce greenhouse gas emissions and improve energy efficiency, it is necessary to dynamize pro-ecological activities in agriculture and in rural areas, including the development of agricultural biogas plants, wind and photovoltaic farms. The use of renewable energy sources can be an important factor in the development and sustainable growth of rural areas in Poland.