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Scientific interest is focusing on different approaches for characterising organic carbon (OC), elemental carbon (EC) and equivalent black carbon (eBC), although EUSAAR2 protocol has been established and frequently used in EU for regulatory purposes. Discrepancies are observed due to thermal protocols used for OC/EC determinations and the effect of the chemical-physical properties of aerosol using optical measurements for eBC. In this work, a long-term inter-comparison of carbon measurements with two widely used protocols (EUSAAR2 and NIOSH870) was performed on PM2.5 and PM10 samples. The influence of the protocol on the evaluation of secondary organic aerosol (SOC) and on the correlation between EC and eBC was investigated. An extensive check of repeatability gave typical uncertainties of ~ 5% for TC and OC, and ~ 10% for EC for both thermal protocols. Results show that OC is statistically comparable between the two protocols but EC is significantly higher with EUSAAR2, especially during the warm season. The ratio OC/EC is lower with EUSAAR2, also showing a seasonality (lower values in the warm season) not observed with NIOSH870. Despite the differences in OC/EC ratios, the contribution of SOC to OC (~ 50%), evaluated using the EC-tracer method, did not differ significantly between the two protocols and for both size fractions. Further, SOC/OC ratios were comparable in cold and warm periods. eBC/EC ratios larger than one for both protocols were obtained, 1.62 (EUSAAR2) and 1.92 (NIOSH870), and also correlated with the ratio OC/EC for both protocols, especially in the cold season. [ABSTRACT FROM AUTHOR]

A field campaign was performed simultaneously at five measurement sites, having different characteristics, to characterize the spatial distribution of the carbonaceous content in atmospheric aerosol in Southern Italy during the winter season. Organic carbon (OC) and elemental carbon (EC) were measured at urban (Naples), suburban (Lecce), coastal/marine (Lamezia Terme and Capo Granitola), and remote (Monte Curcio) locations. OC and EC mass concentrations were quantified by the thermal-optical transmission (TOT) method, in 24-h PM10 and PM2.5 samples collected on quartz fiber filters, from 25 November 2015 to 1 January 2016. The different sites showed marked differences in the average concentrations of both carbonaceous species. Typically, OC average levels (±standard deviation) were higher at the sites of Naples (12.8 ± 5.1 and 11.8 ± 4.6 μg/m³) and Lecce (10.7 ± 5.8 and 9.0 ± 4.7 μg/m³), followed by Lamezia Terme (4.3 ± 2.0 and 4.0 ± 1.9 μg/m³), Capo Granitola (2.3 ± 1.2 and 1.7 ± 1.1 μg/m³), and Monte Curcio (0.9 ± 0.3 and 0.9 ± 0.3 μg/m³) in PM10 and PM2.5, respectively. Similarly, EC average levels (±standard deviation) were higher at the urban sites of Naples (2.3 ± 1.1 and 1.8 ± 0.5 μg/m³) and Lecce (1.5 ± 0.8 and 1.4 ± 0.7 μg/m³), followed by Lamezia Terme (0.6 ± 0.3 and 0.6 ± 0.3 μg/m³), Capo Granitola (0.3 ± 0.3 and 0.3 ± 0.2 μg/m³), and Monte Curcio (0.06 ± 0.04 and 0.05 ± 0.03 μg/m³) in PM10 and PM2.5, respectively. An opposite trend was observed for the OC/EC ratios ranging from 6.4 to 15.9 in PM10 and from 6.4 to 15.5 in PM2.5 with lower values in urban sites compared to remote sites. Different OC-EC correlations, 0.36 < R2 < 0.90, were found in four observation sites. This behavior suggests the contributions of similar sources and common atmospheric processes in both fractions. No correlations were observed between OC and EC at the site of Naples. The average secondary organic carbon (SOC) concentrations, quantified using the minimum OC/EC ratio method, ranged from 0.4 to 7.6 μg/m³ in PM10 and from 0.4 to 7.2 μg/m³ in PM2.5, accounting from 37 to 59% of total OC in PM10 and from 40 to 57% in PM2.5 with higher percentages in the urban and suburban sites of Naples and Lecce. [ABSTRACT FROM AUTHOR]

Harbours are important hubs for economic growth in both tourism and commercial activities. They are also an environmental burden being a source of atmospheric pollution often localized near cities and industrial complexes. The aim of this study is to quantify the relative contribution of maritime traffic and harbour activities to atmospheric pollutant concentration in the Venice lagoon. The impact of ship traffic was quantified on various pollutants that are not directly included in the current European legislation for shipping emission reduction: (i) gaseous and particulate PAHs; (ii) metals in PM; and (iii) PM and PM. All contributions were correlated with the tonnage of ships during the sampling periods and results were used to evaluate the impact of the European Directive 2005/33/EC on air quality in Venice comparing measurements taken before and after the application of the Directive (year 2010). The outcomes suggest that legislation on ship traffic, which focused on the issue of the emissions of sulphur oxides, could be an efficient method also to reduce the impact of shipping on primary particulate matter concentration; on the other hand, we did not observe a significant reduction in the contribution of ship traffic and harbour activities to particulate PAHs and metals. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Samples of PM10 and PM2.5 were collected discontinuously between 2003 and 2010 at fifteen monitoring sites (urban, background, industrial) in the south-eastern part of Italy using a mobile laboratory. In total, 483 PM105 and 154 PM2.5 samples were collected and chemically analyzed for the determination of metal content. Data were used to investigate concentration differences among the typologies of sites, the seasonal patterns, and the influence of advection of Saharan dust (SD). PM10 and PM2.5 average concentrations increase from background to industrial and urban sites but the ratio PM2.5/PM10 is significantly lower (0.61 ±0.10) in background sites. The average metals concentrations in PM10 and in PM2.5 do not show a clear dependence on site typology apart an increase in crustal elements in background sites and an increase in the enrichment factors of Ni and of Cr in PM10in industrial sites. Urban sites show a statistically significant increase of PM10 average concentration during the cold seasons (autumn and winter), likely associated with the anthropogenic urban emissions, instead, the background sites show a decrease in concentrations during the cold seasons. This could be due to more frequent cases of SD observed in spring and summer periods that mainly influence background sites. The seasonal difference on the average concentration for industrial sites is not statistically significant. The SD cases influence both PM10 and PM2.5 concentrations but their effect is significantly larger on PM10. Over the studied area, the effect is relatively limited on long-term average PM10 (estimated increase of 3.2%) and PM2.5 (estimated increase of 1.5%) concentrations but it is significant on daily concentrations. It is estimated an increase of 22% of the probability to overcome the air quality standard daily threshold for PM10. [ABSTRACT FROM AUTHOR]

The results of an experimental analysis carried out to investigate PM2.5 concentration levels and the content of polycyclic aromatic hydrocarbons, as well as inorganic trace elements in the atmospheric particles are presented. Measurements were taken with a micrometeorological station equipped with an optical PM2.5 detector, and simultaneously, particles were collected on filters for subsequent chemical analyses. The average value of daily PM2.5 concentration is 21.5 ug/m3 and real-time measurements indicate that the average concentration during the day (8 am to 8 pm) is about 25% lower than the nocturnal average. Short-time averages of PM2.5 decrease when the wind speed increases as consequence of the more efficient mixing. Meteorological measurements indicate the presence of a local daily (breeze) circulation with wind blowing from the Alps or the Adriatic Sea and, during this circulation, larger concentrations were observed, with wind coming from the Alps. Days of high PM2.5 concentration with dominant anthropic or with prevalent crustal contributions were identified. Regarding trace metals, their average concentrations are comparable to those found in others urban areas, except for Cd (3 ng m-3), probably due to the presence of glass- works in Murano. The highest concentrations are observed for K (99 ng m-3) and Na (73 ng m-3), which are the main constituents of marine spray, while the lowest concentrations are observed for elements such as Cs and Co (respectively 0.01 and 0.02 ng m-3). Also the concentrations of PAH are comparable with those of other industrial areas, as their sum ranges from 0.16 ng m-3 to 3.73 ng m-3, but if considered as B(a)P toxicity equivalent, they are largely lower (0.036±0.026 ng m-3). From the analyses of discriminating ratios, it has been found that the main origin of PAH in PM2.5 samples may be petrogenic, probably related to the presence of refinery and petrochemical plants on the mainland, although the contribution of combustion processes cannot be excluded. [ABSTRACT FROM AUTHOR]

Vinyl chloride (VC) is classified as a group 1 carcinogen to humans by the International Agency for Research on Cancer, and inhalation is considered to be an important route of occupational exposure. In addition, increasing numbers of studies have observed adverse health effects in people living in the vicinity of petrochemical complexes. The objective of this study was to investigate the adverse in vivo health effects on the lungs and liver caused by pulmonary exposure to low-level VC. BALB/c mice were repeatedly intranasally administrated 50 µL/mouse VC at 0, 1, and 200 ng/mL (5 days/week) for 1, 2, and 3 weeks. We observed that exposure to 1 and 200 ng/mL VC significantly increased the tidal volume (μL). Dynamic compliance (mL/cmH2O) significantly decreased after exposure to 200 ng/mL VC for 3 weeks. Total protein, lactate dehydrogenase (LDH), and interleukin (IL)-6 levels in bronchoalveolar lavage fluid (BALF) significantly increased after exposure to 200 ng/mL VC for 2 and/or 3 weeks. Significant decreases in 8-isoprostane and caspase-3 and an increase in IL-6 in the lungs were found after VC exposure for 2 and/or 3 weeks. We observed that aspartate aminotransferase (AST), alkaline phosphatase (ALKP), albumin (ALB), and globulin (GLOB) had significantly increased after three weeks of VC exposure, whereas the ALB/GLOB ratio had significantly decreased after 3 weeks of exposure to VC. IL-6 in the liver increased after exposure to 1 ng/mL VC, but decreased after exposure to 200 ng/mL. IL-1β in the liver significantly decreased following exposure to 200 ng/mL VC, whereas tumor necrosis factor (TNF)-α and caspase-3 significantly increased. Hepatic inflammatory infiltration was confirmed by histological observations. In conclusion, sub-chronic and repeated exposure to low levels of VC can cause lung and liver toxicity in vivo. Attention should be paid to all situations where humans are frequently exposed to elevated VC levels such as workplaces or residents living in the vicinity of petrochemical complexes. [ABSTRACT FROM AUTHOR]

With the current COVID-19 pandemic being spread all over the world, lockdown measures are being implemented, making air pollution levels go down in several countries. In this context, the air quality changes in the highly populated and trafficked Brazilian states of São Paulo (SP) and Rio de Janeiro (RJ) were addressed using a combination of satellite and ground-based daily data analysis. We explored nitrogen dioxide (NO 2 ) and fine particulate matter (PM 2.5 ) daily levels for the month of May from 2015–2020. Daily measurements of NO 2 column concentrations from the Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite were analyzed and decreases of 42% and 49.6% were found for SP and RJ, respectively, during the year 2020 compared to the 2015–2019 average. Besides NO 2 column retrievals, ground-based data measured by the Brazilian States Environmental Institutions were analyzed and correlated with satellite retrievals. Correlation coefficients between year-to-year changes in satellite column and ground-based concentrations were 77% and 53% in SP and RJ, respectively. Ground-based data showed 13.3% and 18.8% decrease in NO 2 levels for SP and RJ, respectively, in 2020 compared to 2019. In SP, no significant change in PM 2.5 was observed in 2020 compared to 2019. To further isolate the effect of emissions reduction due to the lockdown, meteorological data and number of wildfire hotspots were analyzed. NO 2 concentrations showed negative and positive correlations with wind speed and temperature, respectively. PM 2.5 concentration distributions suggested an influence by the wildfires in the southeast region of the country. Synergistic analyses of satellite retrievals, surface level concentrations, and weather data provide a more complete picture of changes to pollutant levels. [ABSTRACT FROM AUTHOR]

The accumulated particulate matter concentration at a given vertical column due to traffic sources in urban area has many important consequences. This task, however, imposes a major challenge, since the problem of realistic pollutant dispersion in an urban environment is a very demanding task, both theoretically and computationally. This is mainly due to the highly inhomogeneous three dimensional turbulent flow regime in the urban canopy roughness sublayer, which is far from "local equilibrium" between shear production and dissipation. We present here a mass-consistent urban Lagrangian stochastic model for pollutants dispersion, where the flow field is modeled using a hybrid approach by which we model the surface layer based on the typical turbulent scales, both of the canopy and in the surface layer inertial sub-layer. In particular it relies on representing the canopy aerodynamically as a porous medium by spatial averaging the equations of motion, with the assumption that the canopy is laterally uniform on a scale much larger than the buildings but smaller than the urban block/neighbourhood, i.e., at the sub-urban-block scale. Choosing the spatial representative averaging volume allows the averaged variables to reflect the characteristic vertical heterogeneity of the canopy but to smooth out smaller scale spatial fluctuations caused as air flows in between the buildings. This modeling approach serves as the base for a realistic and efficient methodology for the calculation of the accumulated concentration from multiple traffic sources for any vertical column in the urban area. The existence of multiple traffic sources impose further difficulty since the computational effort required is very demanding for practical uses. Therefore, footprint analysis screening was introduced to identify the relevant part of the urban area which contributes to the chosen column. All the traffic sources in this footprint area where merged into several areal sources, further used for the evaluation of the concentration profile. This methodology was implemented for four cases in the Tel Aviv metropolitan area based on several selected summer climatological scenarios. We present different typical behaviors, demonstrating combination of source structure, urban morphology, flow characteristics, and the resultant dispersion pattern in each case. [ABSTRACT FROM AUTHOR]

Due to the exponential growth of the SARS-CoV-2 pandemic in Spain (2020), the Spanish Government adopted lockdown measures as mitigating strategies to reduce the spread of the pandemic from 14 March. In this paper, we report the results of the change in air quality at two Atlantic Coastal European cities (Northwest Spain) during five lockdown weeks. The temporal evolution of gaseous (nitrogen oxides, comprising NOx, NO, and NO2; sulfur dioxide, SO2; carbon monoxide, CO; and ozone, O3) and particulate matter (PM10; PM2.5; and equivalent black carbon, eBC) pollutants were recorded before (7 February to 13 March 2020) and during the first five lockdown weeks (14 March to 20 April 2020) at seven air quality monitoring stations (urban background, traffic, and industrial) in the cities of A Coruña and Vigo. The influences of the backward trajectories and meteorological parameters on air pollutant concentrations were considered during the studied period. The temporal trends indicate that the concentrations of almost all species steadily decreased during the lockdown period with statistical significance, with respect to the pre-lockdown period. In this context, great reductions were observed for pollutants related mainly to fossil fuel combustion, road traffic, and shipping emissions (−38 to −78% for NO, −22 to −69% for NO2, −26 to −75% for NOx, −3 to −77% for SO2, −21% for CO, −25 to −49% for PM10, −10 to −38% for PM2.5, and −29 to −51% for eBC). Conversely, O3 concentrations increased from +5 to +16%. Finally, pollutant concentration data for 14 March to 20 April of 2020 were compared with those of the previous two years. The results show that the overall air pollutants levels were higher during 2018–2019 than during the lockdown period. [ABSTRACT FROM AUTHOR]

Similarly to other countries, the first wave of the COVID pandemic induced a collapse of mobility in Hungary during the spring of 2020. From the environmental perspective, the obtained road traffic reduction of 20–50% could be regarded as an undesired traffic regulation experiment. Air quality impacts within Hungary were evaluated based on data from 52 monitoring sites measuring concentrations of pollutants NOx, O3, and PM10. Air pollution during the lockdown was compared to the same period (February–June) in the reference years 2014–2019. The large spatial heterogeneity of the air quality response was explored. The emission reduction coincided with the extreme weather of 2020, characterized by unusually warm pre-lockdown February and spring drought. The anomalously low pre-lockdown air pollution was further reduced (NOx) or increased (PM10) during the restrictions. Compared to the previous years, NOx concentrations during the curfew were found to differ between −4.1 and +0.2 standard deviations (median −1.55 SD), or −45% and +3% (median −18%) among different monitoring locations. Ozone concentrations were unusually high due to both weather and chemical reasons (median +11% or +0.8 SD), while the PM10 response was modest and largely weather-driven (median +7% or +0.4 SD). [ABSTRACT FROM AUTHOR]

Long and short-term exposure to atmospheric particulate matter (PM) has detrimental effects on human health. The effective mechanisms leading to PM toxicity are still not fully understood, even if it is known that physical-chemical properties, strongly influenced by sources and atmospheric processes, are known to play an important role. In this work, PM10 samples were collected, at an urban background site in southern Italy, to determine cytotoxicity (using MTT test on A549 cells), genotoxicity (using the comet assay), and intracellular oxidative stress on A549 cells exposed for 24 h to aqueous extracts of PM10 samples. Organic carbon (OC) and elemental carbon (EC) content of PM10 and acellular determination of oxidative potential with DTT assay were performed to compare results of acellular and cellular biological assays. Cellular (OSGCV and MTTV) and acellular (OPDTTV) outcomes, normalized in volume, are well correlated (statistically significant results) with carbon content suggesting that combustion sources play an important role in determining cellular oxidative stress and cytotoxicity of PM10. Even if the number of data is limited, genotoxicity results are well correlated (Pearson r > 0.95) with OSGCV and MTTV, and a weaker, but statistically significant correlation was observed with OPDTTV. OSGCV is well correlated with the cell mortality observed with the MTTV test and a lower, but still statistically significant correlation is observed between MTTV and OPDDTV. A statistically significant correlation was found between OPDTTV and OSGCV results. When the outcomes of the cellular and acellular assay are compared normalized in mass (i.e., intrinsic values), the correlations become significantly weaker suggesting that the different sources acting on the site produces particulate matter with different toxicological potential influencing differently the biological tests studied. [ABSTRACT FROM AUTHOR]

Deposition of N and heavy metals can impact ecological and human health. This state-of-the-art review addresses spatial and temporal trends of atmospheric deposition as monitored by element accumulation in moss and compares heavy metals Critical Loads for protecting human health and ecosystem's integrity with modelled deposition. The element accumulation due to deposition was measured at up to 1026 sites collected across Germany 1990–2015. The deposition data were derived from chemical transport modelling and evaluated with regard to Critical Loads published in relevant legal regulations. The moss data indicate declining nitrogen and HM deposition. Ecosystem and human health Critical Loads for As, Ni, Zn, and Cr were not exceeded in Germany 2009–2011. Respective Critical Loads were exceeded by Hg and Pb inputs, especially in the low rainfall regions with forest coverage. The Critical Load for Cu was exceeded by atmospheric deposition in 2010 in two regions. Human health Critical Loads for Cd were not exceeded by atmospheric deposition in 2010. However, the maximum deposition in 2010 exceeded the lowest human health Critical Load. This impact assessment was based only on deposition but not on inputs from other sources such as fertilizers. Therefore, the assessment should be expanded with regard to other HM sources and specified for different ecosystem types. [ABSTRACT FROM AUTHOR]

Continuous measurements of particle number size distributions in the size range from 10 nm to 800 nm were performed from 2015 to 2019 at the ECO Environmental-Climate Observatory of Lecce (Global Atmosphere Watch Programme/Aerosol, Clouds and Trace Gases Research Infrastructure (GAW/ACTRIS) regional station). The main objectives of this work were to investigate the daily, weekly and seasonal trends of particle number concentrations and their dependence on meteorological parameters gathering information on potential sources. The highest total number concentrations were observed during autumn-winter with average values nearly twice as high as in summer. More than 52% of total particle number concentration consisted of Aitken mode (20 nm < particle diameter (Dp) < 100 nm) particles followed by accumulation (100 nm < Dp < 800 nm) and nucleation (10 nm < Dp < 20 nm) modes representing, respectively, 27% and 21% of particles. The total number concentration was usually significantly higher during workdays than during weekends/holidays in all years, showing a trend likely correlated with local traffic activities. The number concentration of each particle mode showed a characteristic daily variation that was different in cold and warm seasons. The highest concentrations of the Aitken and accumulation particle mode were observed in the morning and the late evening, during typical rush hour traffic times, highlighting that the two-particle size ranges are related, although there was significant variation in the number concentrations. The peak in the number concentrations of the nucleation mode observed in the midday of spring and summer can be attributed to the intensive formation of new particles from gaseous precursors. Based on Pearson coefficients between particle number concentrations and meteorological parameters, temperature, and wind speed had significant negative relationships with the Aitken and accumulation particle number concentrations, whereas relative humidity was positively correlated. No significant correlations were found for the nucleation particle number concentrations. [ABSTRACT FROM AUTHOR]

In spite of the widely recognized negative effect of air pollution on stone used in historic building heritage located in urban areas and the numerous studies internationally developed on this topic, gaps still remain in measuring deposition fluxes on architectural surfaces and developing proper tools for short- and long-term management of cultural heritage in polluted areas in a changing environment. Two-years long field exposure tests with model samples are currently under execution in Italian cities characterized by different environmental conditions, as a non-invasive methodological approach for investigating the impact of urban pollution on carbonate stones (marble and limestone). Several analytical techniques (both physical and chemical) are used for characterising the state of degradation of the exposed stone specimens while aerosol monitoring campaigns allow to compare the atmospheric components with those actually accumulate on samples surface. After a description of the methodological approach of this study and a general environmental characterisation of each selected site, results of aerosol monitoring campaigns (including bioaerosol) and colorimetric analyses performed during the whole period of exposure in Bologna are here presented and discussed. [ABSTRACT FROM AUTHOR]