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In this work, new particle formation events (NPFs) occurring at two locations in southern Italy, the urban background site of Lecce (ECO station) and the coastal site of Lamezia Terme (LMT station), are identified and analyzed. The study aims to compare the properties of NPF events at the two sites, located 225 km away from each other and characterized by marked differences in terms of emission sources and local weather dynamics. Continuous measurements of particle number size distributions, in the size range from 10 to 800 m, were performed at both sites by a mobility particle size spectrometer (MPSS). The occurrence of NPF events, observed throughout the study period that lasted 5 years, produced different results in terms of frequency of occurrence: 25 % of the days at ECO and 9 % at LMT. NPF events showed seasonal patterns: higher frequency during spring and summer at the urban background site and the autumn–winter period at the coastal site. Some of these events happened simultaneously at both sites, indicating the occurrence of the nucleation process on a large spatial scale. Cluster analysis of 72 h back trajectories showed that during the NPF events the two stations were influenced by similar air masses, most of which originated from the north-western direction. Local meteorological conditions characterized by high pressure, with a prevalence of clear skies, low levels of relative humidity (RH < 52 %), and moderate winds (3–4 m s−1) dominated the NPF events at both sites. Notable differences were observed in SO2 and PM2.5 concentrations and H2SO4 proxy levels, resulting in ∼65 %, ∼80 %, and 50 % lower levels at LMT compared to ECO, respectively. It is likely that the lower level of that which is recognized as one of the main gas precursors involved in the nucleation process could be responsible for the smaller NPF frequency of occurrence (∼60 % less than ECO) observed in LMT.

Atmospheric particulate matter (PM) is one of the major risks for global health. The exact mechanisms of toxicity are still not completely understood leading to contrasting results when different toxicity metrics are compared. In this work, PM10 was collected at three sites for the determination of acellular oxidative potential (OP), intracellular oxidative stress (OSGC), cytotoxicity (MTT assay), and genotoxicity (Comet assay). The in vitro tests were done on the A549 cell line. The objective was to investigate the correlations among acellular and intracellular toxicity indicators, the variability among the sites, and how these correlations were influenced by the main sources by using PMF receptor model coupled with MLR. The OPDTTV, OSGCV, and cytotoxicity were strongly influenced by combustion sources. Advection of African dust led to lower-than-average intrinsic toxicity indicators. OPDTTV and OSGCV showed site-dependent correlations suggesting that acellular OP may not be fully representative of the intracellular oxidative stress at all sites and conditions. Cytotoxicity correlated with both OPDTTV and OSGCV at two sites out of three and the strength of the correlation was larger with OSGCV. Genotoxicity was correlated with cytotoxicity at all sites and correlated with both, OPDTTV and OSGCV, at two sites out of three. Results suggest that several toxicity indicators are useful to gain a global picture of the potential health effects of PM.

Airborne particulate matter (PM) is studied because of its effects on human health and climate change. PM long-term characterisation allows identifying trends and evaluating the outcomes of environmental protection policies. This work is aimed to study the inter-annual variability of PM

A chemical characterization of PM10 collected at hydrofoil exhaust stacks was performed conducting two on-board measuring campaigns, with the aim of assessing the ship emission impact on PM10 collected in the coastal area of Naples (Southern Italy) and providing information about the characteristics of this important PM emission source. Samples were analysed determining the contribution of different chemical parameters to PM10’s mass, which consisted of polycyclic aromatic hydrocarbons (PAHs) (0.10 ± 0.12%), total carbon (61.9% ± 20.0%, with 40.4% of organic carbon, OC, and 21.5% of elemental carbon, EC) and elemental fraction (0.44% ± 1.00%). Differences in terms of composition and chemical parameter profiles were observed between samples collected during offshore navigation (Off) and samples collected during shunting operations (SO), the latter of higher concern on a local scale. For SO samples, lower contributions of OC and EC were observed (39.7% and 19.6% respectively) compared to Off samples (41.5% and 24.2%), and an increase in terms of elements (from 0.32 to 0.51%) and PAHs (from 0.06 to 0.12%) concentrations was observed. In addition, enrichment factors (EFs) for some elements such as V, Zn, Cd, Cu, Ag and Hg as well as PAHs profile varied significantly between SO and Off. Data presented here were compared with data on chemical composition of PM10 sampled in a tunnel, in a background site and in an urban site in the city of Naples. Results indicated that shipping activities contributed significantly to the emission of V and, in some extent, Zn and Cd; in addition, PAH profiles indicated a greater contribution to urban PM10 from vehicular traffic than shipping emissions. These results can significantly contribute to the correct evaluation of the influence of shipping emission on PM10 generation in urban coastal areas and can be a useful reference for similar studies. The coastal area of Naples is an important example of the coexistence of residential, touristic and natural areas with pollutants emission sources including, among the others, shipping emissions. In this and similar contexts, it is important to distinguish the contribution of each emission source to clearly define environmental control policies.

Airborne particulate matter (PM) is studied because of its effects on human health and climate change. PM long-term characterisation allows identifying trends and evaluating the outcomes of environmental protection policies. This work is aimed to study the inter-annual variability of PM2.5 and PM10 concentrations and chemical composition in an urban background site (Italy). A dataset of daily PM2.5 and PM10 was collected in the period 2016-2017, including the content of OC, EC, major water-soluble ions, main metals, and compared to a similar dataset collected in the period 2013-2014. Oxidative potential using DTT assay (dithiothreitol) was evaluated and expressed in DTTV as 0.39nmol/min·m3 in PM10 and 0.29 in PM2.5nmol/min·m3. PM source apportionment was computed using the EPA PMF5.0 model and source contributions compared with those of a previous dataset collected between 2013 and 2014. Multi linear regression analysis identified which source contributed (p&nbsp

Many countries imposed lockdown (LD) to limit the spread of COVID-19, which led to a reduction in the emission of anthropogenic atmospheric pollutants. Several studies have investigated the effects of LD on air quality, mostly in urban settings and criteria pollutants. However, less information is available on background sites, and virtually no information is available on particle number size distribution (PNSD). This study investigated the effect of LD on air quality at an urban background site representing a near coast area in the central Mediterranean. The analysis focused on equivalent black carbon (eBC), particle mass concentrations in different size fractions: PM

COVID-19 pandemic raised a debate regarding the role of airborne transmission. Information regarding virus-laden aerosol concentrations is still scarce in community indoors and what are the risks for general public and the efficiency of restriction policies. This work investigates, for the first time in Italy, the presence of SARS-CoV-2 RNA in air samples collected in different community indoors (one train station, two food markets, one canteen, one shopping centre, one hair salon, and one pharmacy) in three Italian cities: metropolitan city of Venice (NE of Italy), Bologna (central Italy), and Lecce (SE of Italy). Air samples were collected during the maximum spread of the second wave of pandemic in Italy (November and December 2020). All collected samples tested negative for the presence of SARS-CoV-2, using both real-time RT-PCR and ddPCR, and no significant differences were observed comparing samples taken with and without customers. Modelling average concentrations, using influx of customers’ data and local epidemiological information, indicated low values (i.e. < 0.8 copies m−3 when cotton facemasks are used and even lower for surgical facemasks). The results, even if with some limitations, suggest that the restrictive policies enforced could effectively reduce the risk of airborne transmissions in the community indoor investigated, providing that physical distance is respected. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-021-16737-7.

In this study, simultaneous monitoring of indoor and outdoor Volatile Organic Compounds (VOCs) was carried out in a school, by both Radiello® cartridges and real-time monitors (Corvus, IonScience Ltd., Fowlmere UK). Moreover, an outdoor air quality assessment was performed with data from an air quality monitoring station (ARPA Puglia) located close to the school. In particular, VOCs, Benzene, Toluene, Ethylbenzene, and Xilenes concentrations, obtained by using Radiello® diffusive samplers, were monitored in two classrooms, two bathrooms, and outside of the school building for three weeks during winter 2019. Simultaneously, the Total VOC (TVOC) concentrations were measured by means of real-time monitors inside and outside the classroom in order to individuate the activation of sources during the sampling campaign days. The results evidence that indoor TVOC concentrations were bigger than those outdoors, this suggests the presence of indoor pollutant sources, both in the classrooms and the bathrooms. The results of our study can help the school management by the following recommendations: increasing ventilation in classrooms during school activities and after cleaning, involving students in discussions regarding the use of acrylic paints, permanent markers, perfumes and deodorants, and the limitation of smoking activities both in bathrooms and outdoor spaces.

Airborne transmission of SARS-CoV-2 has been object of debate in the scientific community since the beginning of COVID-19 pandemic. This mechanism of transmission could arise from virus-laden aerosol released by infected individuals and it is influenced by several factors. Among these, the concentration and size distribution of virus-laden particles play an important role. The knowledge regarding aerosol transmission increases as new evidence is collected in different studies, even if it is not yet available a standard protocol regarding air sampling and analysis, which can create difficulties in the interpretation and application of results. This work reports a systematic review of current knowledge gained by 73 published papers on experimental determination of SARS-CoV-2 RNA in air comparing different environments: outdoors, indoor hospitals and healthcare settings, and public community indoors. Selected papers furnished 77 datasets: outdoor studies (9/77, 11.7%) and indoor studies (68/77. 88.3%). The indoor datasets in hospitals were the vast majority (58/68, 85.3%), and the remaining (10/68, 14.7%) were classified as community indoors. The fraction of studies having positive samples, as well as positivity rates (i.e. ratios between positive and total samples) are significantly larger in hospitals compared to the other typologies of sites. Contamination of surfaces was more frequent (in indoor datasets) compared to contamination of air samples; however, the average positivity rate was lower compared to that of air. Concentrations of SARS-CoV-2 RNA in air were highly variables and, on average, lower in outdoors compared to indoors. Among indoors, concentrations in community indoors appear to be lower than those in hospitals and healthcare settings., Graphical abstract Unlabelled Image

Since the beginning of COVID-19 pandemic there have been scientific questions regarding the role of airborne transmission of SARS-CoV-2 and its influence on COVID-19 spread. One of the key parameters to ascertain the risks of airborne transmission is the concentrations of SARS-CoV-2 genetic material (RNA) in air in different environments. This work investigates this aspect in both outdoor and indoor environments in different towns of Italy during the first and the second wave of pandemic. Outdoor samples were collected using both PM10 low-volume (2.3 m3/h) samplers for 48h in parallel in Venice (Veneto region, north-east of Italy) and Lecce (Puglia region, south-east of Italy) during the first wave of pandemic. In addition, two samples for each site were collected using MOUDI multistage impactors (1.8 m3/h for six days sampling) able to separate 12 size ranges of particles. During the second wave of pandemic in Italy (November-December 2020), air samples were collected in different community indoor environments: one train station and two food markets in metropolitan city of Venice (Veneto Region); one canteen in Bologna (Emilia-Romagna region, central Italy); one shopping centre, one hair salon, and one pharmacy in Lecce (Puglia region). All collected samples were analysed to individuate the presence of SARS-CoV-2 RNA traces using two independent approaches: real-time RT-PCR and ddPCR (Chirizzi et al., 2021). Recovery tests done using Mengo virus strain MC0 indicate a recovery of about 50%. Modelling of expected average concentrations in the different environments, were also done using influx of customers data and local epidemiological information to compare with measurements. Results show a negligible risk for airborne transmission in residential outdoor zones, excluding crowed areas. In the community indoor environments investigated, indoor ventilation seems to play an important role in reducing concentrations of virus-laden particles as well as the use of facemasks.

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.

The aim of this study is to characterize the air quality in a Mediterranean port city. The impact of ship emissions on both gaseous and particulate pollutants has been investigated through an integrated methodology which includes atmospheric flow and dispersion numerical modelling as well as chemical composition and statistical analyses. Specifically, chemical compositional data (ionic fraction, carbonaceous compounds, and metals) of PM2.5 were acquired during an experimental field campaign carried out in the port city of Brindisi (Apulia Region, Southern Italy). The sampling site was located on the roof of a building (ASI) within the port area. Given the complexity of the site in which both domestic buildings and a large industrial area are present, analyses were done by selecting different wind sectors to test different techniques to discriminate between sources. Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA) were applied to evaluate statistical differences in the composition of PM2.5 sampled within the area when the sampling site was downwind to the port or to the urban-industrial area. Only LDA allowed to discriminate the separation between urban-industrial and port macroareas. Those results were further confirmed in terms of PM2.5 concentrations directly associated to ship emissions using a coupled modelling approach. The mesoscale model BOLCHEM was used to investigate the contribution of ship emissions both on primary and secondary PM2.5 concentration in the area surrounding the port, as well as on PM10, NOX and O3 concentrations. Then, the model was coupled offline with the local dispersion model ADMS-Urban. The adopted approach was crucial to evaluate the spatial distribution of the impact of ship emissions. BOLCHEM results showed that in the cell of the port the average impact of ship emissions on NOX was 37.6%, and −11.7% on O3. The average impact on PM2.5 was 6.1%, distributed between primary (2.7%) and secondary fraction (3.4%). At local scale, the analysis of high-resolution modelling results obtained from ADMS-Urban highlighted that, at ASI position, the impact of ship emissions on PM2.5 was 6.8% when the sampling site was positioned downwind to the port area and reduced to lower than 3.0% at about 2 km from the sources.

Graphical abstract, Highlights • SARS-CoV-2 concentration in outdoor air was measured in north and south Italy. • Size distributions of virus-laden aerosol were investigated at both sites. • SARS-CoV-2 concentrations were, The COVID-19 disease spread at different rates in the different countries and in different regions of the same country, as happened in Italy. Transmission by contact or at close range due to large respiratory droplets is widely accepted, however, the role of airborne transmission due to small respiratory droplets emitted by infected individuals (also asymptomatic) is controversial. It was suggested that outdoor airborne transmission could play a role in determining the differences observed in the spread rate. Concentrations of virus-laden aerosol are still poorly known and contrasting results are reported, especially for outdoor environments. Here we investigated outdoor concentrations and size distributions of virus-laden aerosol simultaneously collected during the pandemic, in May 2020, in northern (Veneto) and southern (Apulia) regions of Italy. The two regions exhibited significantly different prevalence of COVID-19. Genetic material of SARS-CoV-2 (RNA) was determined, using both real time RT-PCR and ddPCR, in air samples collected using PM10 samplers and cascade impactors able to separate 12 size ranges from nanoparticles (diameter D 18 µm). Air samples tested negative for the presence of SARS-CoV-2 at both sites, viral particles concentrations were

Saharan dust (SD) is a relevant source of mineral particles (PM) for the Mediterranean region with potential impacts on air quality and climate. In this work, a long-term analysis of 56 SD events recorded between 2013 and 2018 at the Environmental-Climate Observatory of Lecce (SE Italy) was performed to investigate the effects and the seasonality of dust advection on PM2.5 and PM10, on carbon content, and on number and mass size distributions. The average duration of events was 2.6 days (10% of days) with a pronounced seasonality, 12.5% during warm seasons and 7.5% during cold seasons. The average contribution to PM10 was 1.5 μg/m3, between 1.4 μg/m3 (cold seasons) and 1.8 μg/m3 (warm seasons). Contribution to PM2.5 was significantly lower and not negligible during warm seasons (0.5 μg/m3). The impact of SD in south-eastern Italy is comparable with that in central Italy rather than to that observed in south-western Italy. Looking at PM10, 70 days exceeding legislation threshold were observed (4.8% of days), 22.9% of these exceedances were during SD. Extreme SD events (contributions > 100 μg/m3) cover 2% of the cases. Comparison of carbon content between SD and non-SD days shows that SD does not influence EC and eBC concentrations; however, SD contributes to secondary organic aerosol in the coarse fraction (PM10-2.5). Size distributions (in number and mass) measured during SD and non-SD days show that SD increases the particle number concentrations for diameters (Dp) larger than about 0.9–1 μm. Maximum increase was for Dp 2.5–3 μm.

Size-segregated analysis of organic and elemental carbon (EC, OC) in aerosol is essential in understanding sources and effects on the environment. However, these studies are scarce, especially in coastal areas stressed by anthropogenic emissions and with interactions between anthropogenic and natural emissions. To partially fill this lack of information, aerosol size segregated samples were taken between August 2018 and May 2019, using a MOUDI impactor. Measurements were performed in two port-cities of Northern Adriatic Sea, Venice (Italy) and Rijeka (Croatia). A thermal-optical analysis (EUSAAR2) allowed EC and OC determination in different size ranges. For Rijeka site, the water soluble organic carbon content (WSOC) was analysed. OC and EC average concentrations in Venice were 3.16 (+/- 0.97) and 0.40 (+/- 0.13) mu g/m(3); in Rijeka: 2.48 (+/- 0.65) and 0.37 (+/- 0.08) mu g/m(3). The OC size distributions were bimodal at both sites, with an accumulation mode in the size range 0.56-0.32 mu m, a coarse mode in the range 5.6-3.2 mu m. EC showed a bimodal distribution in Rijeka, a single fine mode in Venice. The EC/TC ratio was large in the fine mode at both sites, however, in Rijeka non-negligible values were found in the coarse fraction suggesting contributions from resuspension of carbon-loaded dust and mixing of anthropogenic particles with sea spray. The WSOC/OC analysis as function of particle size in Rijeka showed a total value of 0.51 (+/- 0.12) with an increase in the coarse fraction likely due to contributions of water soluble carbon from sea spray and biogenic emissions.

Organic (OC) and Elemental Carbon (EC) are important components of atmospheric aerosol particles, playing a key role in climate system and potentially affecting human health. There is a lack of data reported for Southern Italy and this work aims to fill this gap, focusing the attention on the long-term trends of OC and EC concentrations in PM 2.5 and PM 10 , and on atmospheric processes and sources influencing seasonal variability. Measurements were taken at the Environmental-Climate Observatory of Lecce (SE Italy, 40°20′8″N-18°07′28″E, 37 m a.s.l.), regional station of the Global Atmosphere Watch program (GAW-WMO). Daily PM 10 and PM 2.5 samples were collected between July 2013 and July 2016. In addition, starting in December 2014, simultaneous equivalent Black Carbon (eBC) concentrations in PM 10 were measured using a Multi Angle Absorption Photometer. A subset of 722 PM samples (361 for each size fraction) was analysed by using a thermo-optical method with a Sunset Laboratory OC/EC analyser, to determine elemental and organic carbon concentrations. The average PM 10 and PM 2.5 concentrations were 28.8 μg/m 3 and 17.5 μg/m 3 . The average OC and EC concentrations in PM 10 were 5.4 μg/m 3 and 0.8 μg/m 3 , in PM 2.5 these were 4.7 μg/m 3 and 0.6 μg/m 3 . Carbonaceous content was larger during cold season with respect to warm season as well as secondary organic carbon (SOC) that was evaluated using the OC/EC minimum ratio method. SOC was mainly segregated in PM 2.5 and represented 53% - 75% of the total OC. A subset of EC data was compared with eBC measurements, showing a good correlation (R 2 = 0.80), however, eBC concentrations were higher than EC concentrations of an average factor of 1.95 (+/− 0.55 standard deviation). This could be explained by the presence of a contribution of Brown Carbon (BrC), for example from biomass burning, in eBC measurements. Weekly patterns showed a slight decrease of carbon content during weekends with respect to weekdays especially visible on eBC concentration due to the decrease of road traffic emissions. The daily patterns of hourly eBC concentrations showed a decrease in central diurnal hours, due to the cycle of planetary boundary-layer height, and concentrations peaks during rush hours due to road traffic emissions.

Comparison of fine and coarse fractions in terms of sources and dynamics is scarce in southeast Mediterranean countries; differences are relevant because of the importance of natural sources like sea spray and Saharan dust advection, because most of the monitoring networks are limited to PM10. In this work, the main seasonal variabilities of sources and processes involving fine and coarse PM (particulate matter) were studied at the Environmental-Climate Observatory of Lecce (Southern Italy). Simultaneous PM2.5 and PM10 samples were collected between July 2013 and July 2014 and chemically analysed to determine concentrations of several species: OC (organic carbon) and EC (elemental carbon) via thermo-optical analysis, 9 major ions via IC, and 23 metals via ICP-MS. Data was processed through mass closure analysis and Positive Matrix Factorization (PMF) receptor model characterizing seasonal variabilities of nine sources contributions. Organic and inorganic secondary aerosol accounts for 43% of PM2.5 and 12% of PM2.5–10 with small seasonal changes. SIA (secondary inorganic aerosol) seasonal pattern is opposite to that of SOC (secondary organic carbon). SOC is larger during the cold period, sulphate (the major contributor to SIA) is larger during summer. Two forms of nitrate were identified: NaNO3, correlated with chloride depletion and aging of sea-spray, mainly present in PM2.5–10; NH4NO3 more abundant in PM2.5. Biomass burning is a relevant source with larger contribution during autumn and winter because of the influence of domestic heating, however, is not negligible in spring and summer, because of the contributions of fires and agricultural practices. Mass closure analysis and PMF results identify two soil sources: crustal associated to long range transport and carbonates associated to local resuspended dust. Both sources contributes to the coarse fraction and have different dynamics with crustal source contributing mainly in high winds from SE conditions and carbonates during high winds from North direction.

Exposure to atmospheric particulate matter (PM) leads to adverse health effects although the exact mechanisms of toxicity are still poorly understood. Several studies suggested that a large number of PM health effects could be due to the oxidative potential (OP) of ambient particles leading to high concentrations of reactive oxygen species (ROS). The contribution to OP of specific anthropogenic sources like road traffic, biomass burning, and industrial emissions has been investigated in several sites. However, information about the OP of natural sources are scarce and no data is available regarding the OP during Saharan dust outbreaks (SDO) in Mediterranean regions. This work uses the a-cellular DTT (dithiothreitol) assay to evaluate OP of the water-soluble fraction of PM2.5 and PM10 collected at an urban background site in Southern Italy. OP values in three groups of samples were compared: standard characterised by concentrations similar to the yearly averages; high carbon samples associated to combustion sources (mainly road traffic and biomass burning) and SDO events. DTT activity normalised by sampled air volume (DTTv), representative of personal exposure, and normalised by collected aerosol mass (DTTM), representing source-specific characteristics, were investigated. The DTTv is larger for high PM concentrations. DTTv is well correlated with secondary organic carbon concentration. An increased DTTv response was found for PM2.5 compared to the coarse fraction PM2.5-10. DTTv is larger for high carbon content samples but during SDO events is statistically comparable with that of standard samples. DTTM is larger for PM2,5 compared to PM10 and the relative difference between the two size fractions is maximised during SDO events. This indicates that Saharan dust advection is a natural source of particles having a lower specific OP with respect to the other sources acting on the area (for water-soluble fraction). OP should be taken into account in epidemiological studies to evaluate the potential health risks associated to ROS in regions affected by high pollution events due to Saharan dust advection. (C) 2017 Elsevier Ltd. All rights reserved.

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 PM

Atmospheric particlulate matter (PM) is an heterogeneuous and dynamic mixture of particles with different origins, and its harmful effects are more strongly linked to its size and chemical composition than to its mass. The capability of some chemical compounds, present in airborne particulate matter, to generate reactive oxygen species (ROS) is known as “oxidative potential” (OP), and it represents a useful indicator of PM toxicity. The high production of ROS causes oxidative damages to cells that ultimately can lead to different chronic diseases. Although numerous studies were performed in the last years, however the biological mechanisms of toxicity and their relation with the chemical and physical properties of particulate matter are still largely unknown and futher research is need. In this work the oxidative potential of the water-soluble fraction of PM2.5 and PM10, collected at an urban background site in Southern Italy was investigated. The analysis of the OP were performed using the dithiothreitol (DTT) assay, a surrogate for cellular antioxidants, which analyses the rate of DTT depletion catalysed by chemical species present in the PM. Organic and Elemental carbon content was determined on all the collected samples in order to study the correlation between carbonaceous fractions and oxidative potential as well as to quantify the contribution of the combustion sources. DTT activity normalised by sampled air volume (OPV) and normalised by collected aerosol mass (OPM) were investigated. Results showed a seasonal trend in PM concentrations, in both size fractions, with larger concentrations during the cold seasons compared to the warm seasons. The same trend was also observed in carbonaceous faraction. OPV showed a similar trend with values larger in PM10 compared to PM2.5 as well as greater OPV values was observed in high carbon content samples. OPM was instead larger for PM2.5 than PM10. Also, OPV was well correlated both with mass concentration of PM and carbonaceous fractions, while no significant correlation has been observed with OPM

Several studies focused on harbour impact on air quality of port-cities showing that maritime emissions could be comparable to traffic emissions of a medium-size town having relevant impact on air quality nearby the harbours. In order to plan efficient mitigation strategies, environmental and port authorities have an increasing need of reliable tools for investigating the impact of ships traffic and harbour logistics on atmospheric pollutants. In this work a system based on the integration of measurements collected using a network of low-cost on-line sensors with local scale dispersion modelling was developed. It was implemented, as a pilot action, in the information and management software of the Bari harbour (SE Italy). It can operate in near-real-time, in forecast mode, and on archived data for long-term assessments. It was tested studying the impact of the Bari harbour for the year 2018. The lowest impact was observed for CO, being the pollutant with the lowest share of the contribution of ships (between 8% and 68%) compared with the total harbour contribution. The impacts on PM2.5 and PM10 are larger arriving up to 11.8% of concentrations in the harbour area with an influence of shipping between 44% and 97%. The impact on SO2 is almost solely due to ships and it arrives up to 80% in the harbour area. The impact on NOX ranges from a few percent in the urban area up to 40% in the harbour area and it is the pollutant of major concern regarding compliance with air quality standards.

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 &gt, 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.

During the new coronavirus infection outbreak, the application of strict containment measures entailed a decrease in most human activities, with the consequent reduction of anthropogenic emissions into the atmosphere. In this study, the impact of lockdown on atmospheric particle number concentrations and size distributions is investigated in two different sites of Southern Italy: Lecce and Lamezia Terme, regional stations of the GAW/ACTRIS networks. The effects of restrictions are quantified by comparing submicron particle concentrations, in the size range from 10 nm to 800 nm, measured during the lockdown period and in the same period of previous years, from 2015 to 2019, considering three time intervals: prelockdown, lockdown and postlockdown. Different percentage reductions in total particle number concentrations are observed, −19% and −23% in Lecce and −7% and −4% in Lamezia Terme during lockdown and postlockdown, respectively, with several variations in each subclass of particles. From the comparison, no significant variations of meteorological factors are observed except a reduction of rainfall in 2020, which might explain the higher levels of particle concentrations measured during prelockdown at both stations. In general, the results demonstrate an improvement of air quality, more conspicuous in Lecce than in Lamezia Terme, during the lockdown, with a differed reduction in the concentration of submicronic particles that depends on the different types of sources, their distance from observational sites and local meteorology.

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 &lt, particle diameter (Dp) &lt, 100 nm) particles followed by accumulation (100 nm &lt, Dp &lt, 800 nm) and nucleation (10 nm &lt, 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.

Concentrations, size distributions and particle number vertical turbulent fluxes were measured by the eddy-covariance method at an urban background site in southeastern Italy during the summer. CO2/H2O concentrations and fluxes were also determined together with meteorological parameters. Time series show that particles could be divided into two size classes with negatively-correlated temporal trends in diurnal hours: nanoparticles (diameter Dp &lt, 50 nm) and larger particles (Dp &gt, 50 nm). Larger particles include part of the Aitken mode and the accumulation mode. Nanoparticles peaked in diurnal hours due to the presence of several days with nucleation events when particles Dp &gt, 50 nm were at minimum concentrations. Nucleation increased diurnal total particle concentration by a factor of 2.5, reducing mean and median diameters from Dmean = 62.3 ± 1.2 nm and Dmedian = 29.1 ± 1.3 nm on non-event days to Dmean = 35.4 ± 0.6 nm and Dmedian = 15.5 ± 0.3 nm on event days. During nucleation events, particle deposition increased markedly (i.e., downward fluxes), but no significant changes in CO2 concentrations and fluxes were observed. This is compatible with new particle formation above the measurement height and a consequent net transport towards the surface. Correlation with meteorology shows that the formation of new particles is correlated with solar radiation and favored at high wind velocity.

The impact of ship emissions on the surface concentration of nitrogen oxides (NOx) and ozone (O-3) in the Mediterranean area of the harbour of Brindisi (IT) has been investigated. Numerical simulations have been performed for a summer period of the year 2012, at different spatial scale, using the meso-scale BOLCHEM and the local-scale ADMS-Urban models. Results show that while average ground concentration of primary pollutant NOx increases in the area surrounding the port, a decrease in O-3 concentration is observed.

Exposure to atmospheric particulate matter (PM) leads to adverse health effects and the exact mechanisms of toxicity are still not completely understood. Recent studies suggested that a large number of PM health effects could be due to the oxidative potential (OP) of ambient particles leading to high concentrations of reactive oxygen species (ROS). However, information about the OP of natural sources are scarce and no data is available regarding the OP during Saharan dust outbreaks (SDO) in Mediterranean regions. This work uses the a-cellular DTT (dithiothreitol) assay to evaluate OP of the water-soluble fraction of PM2. 5 and PM10 collected at an urban background site in Southern Italy

Shipping is a growing transport sector representing a relevant share of atmospheric pollutant emissions at global scale. In the Mediterranean Sea, shipping affects air quality of coastal urban areas with potential hazardous effects on both human health and climate. The high number of different approaches for investigating this aspect limits the comparability of results. Furthermore, limited information regarding the inter-annual trends of shipping impacts is available. In this work, an approach integrating emission inventory, numerical modelling (WRF-CAMx modelling system), and experimental measurements at high and low temporal resolution is used to investigate air quality shipping impact in the Adriatic/Ionian area focusing on four port-cities: Brindisi and Venice (Italy), Patras (Greece), and Rijeka (Croatia). Results showed shipping emissions of particulate matter (PM) and NOx comparable to road traffic emissions at all port-cities, with larger contributions to local SO2 emissions. Contributions to PM2.5 ranged between 0.5% (Rijeka) and 7.4% (Brindisi), those to PM10 were between 0.3% (Rijeka) and 5.8% (Brindisi). Contributions to particle number concentration (PNC) showed an impact 2-4 times larger with respect to that on mass concentrations. Shipping impact on gaseous pollutants are larger than those to PM. The contribution to total polycyclic aromatic hydrocarbon (PAHs) concentrations was 82% in Venice and 56% in Brindisi, with a different partition gas-particle because of different meteorological conditions. The inter-annual trends analysis showed the primary contribution to PM concentrations decreasing, due to the implementation of the European legislation on the use of low-sulphur content fuels. This effect was not present on other pollutants like PAHs. (C) 2016 Elsevier Ltd. All rights reserved.

We present a characterization of reactive gases (RG: O3, NO, NO2,SO2, CO) and methane (CH4) variability in the central Mediterranean basin,analyzing in situ measurements at three new permanent WMO/GAW Observatories in Southern Italy: Capo Granitola – CGR (Sicily), Lamezia Terme – LMT (Calabria) and Lecce – ECO (Apulia). At all the measurement sites, a combination of the breeze wind system (especially at CGR and LMT),PBL dynamics, anthropogenic/natural emissions, and photochemistry lead the appearance of well-defined diurnal cycles for the observed RG. According to O3/NOx variability, local emissions appeared to influence CGR and LMT (no NOx data were available for ECO during the period of study) in 4% and 20% of the hourly data, nearby sources in 39% and 40%, remote sources in 31% and 14%, while background O3/NOx were observed in 26% of cases for both the stations. Most of the background O3/NOx were observed during daytime, when offshore air masses usually affected the measurement sites. Local sources of CH4 at CGR can be related to biogenic (oxic) emissions from biomasses along the coastline, while emissions from live stocks can represent a local source of CH4 at LMT. Finally, we provide first hints about the export of O3 from Sicily/Southern Italy to the Mediterranean Sea by comparing simultaneous observations at CGR and Lampedusa (LMP), a small island in the middle of the Strait of Sicily where a WMO/GAW Regional Station is located. In summer,O3 increased by some 7 ppb for transport times lower than 48 h, while no statistical significant differences were observed for travel time longer than 48. This would suggest that photochemical O3 production occurred within air-mass travelling from CGR to LMP, but also that the central Mediterranean MBL represents a O3 sink for relatively aged air-masses.

Il contributo di ISAC-CNR previsto nella Convenzione di ricerca del 15/03/2016 tra ISAC-CNR e la Regione Puglia, rappresentata dal Responsabile Attuativo del Centro Salute Ambiente, prevede due linee di attività: 1) campagne di misura con AMS (High Resolution-Time of Flight-Aerosol Mass Spectrometer). 2) Misura delle concentrazioni e delle distribuzioni dimensionali del particolato atmosferico fine, ultrafine e delle nanoparticelle nell'area di Lecce La Convenzione prevedeva l'erogazione del 40% del contributo (importo totale pari a 70.000 euro) alla stipula della convenzione stessa. Per motivi non dipendenti da ISAC-CNR tale erogazione non è stata effettuata, pertanto le attività previste dall'accordo sono state espletate nelle parti e nei termini consentiti dalla disponibilità di fondi interni all'istituto stesso. Lo scopo di questo report è analizzare i risultati ottenuti nella fase di avvio dello studio relativamente alle due attività menzionate.

Shipping is one of the transport sectors less regulated, although more than 80% of world trade is transported by ships [1] and its share of total anthropogenic emissions is significant, with effects on climate, human health and air quality, especially in coastal areas. Recent studies [2] demonstrated the effectiveness of implementation of the 2005/33/EC European Directive in reducing the impact of ship traffic on aerosol concentrations at local scale, however, the effect on climate is more uncertain. Detailed information regarding the size distribution of the impacts to particles and their correlation with gaseous emissions is needed to investigate the complex air quality-climate interaction of this source. Much of the literature studies focus on NOX, SO2, and particulate matter (PM) emissions while there is a gap of knowledge about the size distribution of emitted particles, especially in coarse fraction. This study was done in the framework of POSEIDON (POllution monitoring of Ship Emission: an IntegrateD approach fOr harbour of the Adriatic basiN) project (MED 2007-2013). The aim was to estimate the contribution of in-port ship emissions to gaseous atmospheric pollutants and to PM of different sizes in a port-city in South-Eastern Italy (Adriatic Sea), after the enforcement of the low-sulphur fuel EU-Directive. Measurements were taken at high temporal resolution at the Passenger Terminal site in the harbour area of Brindisi (40° 38? 43.32? N-17° 57? 36.39? E). Data collected by a Mobile Laboratory, were gaseous pollutants (NO2, NO, O3, SO2; 5 min resolution), particle number concentrations (PNC; 1 min resolution), particle size distribution in the range 0.25-32 ?m (1 min resolution) and NO2 and SO2 flow-rate emissions with a DOAS (Differential Optical Absorption Spectroscopy) remote-sensing system, called GASCOD (Gas Absorption Spectrometer Correlating Optical Differences). The Port Authority provided data of ship traffic and a video camera was used to synchronize all measurements and visually estimate number of vehicles (cars, trucks) during loading/unloading of ships at berth. Characterization of ship plumes in aspect of particle size, gaseous concentrations, duration, ratio NO/NO2, was performed. The impact analysis [3] was applied separating manoeuvring (arrival/departure of ships) and hotelling (loading/unloading activities) phases. Results showed that the primary contribution to PM1 and PM2.5 was significantly lower with respect to those to PNC for both phases, confirming that the majority of the particles emitted were in the ultrafine size range. Manoeuvring phase was characterized by higher impacts to SO2, NO, and NO2 than those to PNC, PM1 and PM2.5. Hotelling phase represented a significant share of the impact for NO, NO2, PNC but gave a low contribution to SO2 impact (due to low-sulphur fuel). Ultrafine particles (Dp1) fraction while accumulation mode particles (0.25

Shipping is one of the transport sectors less regulated, although more than 80% of world trade is transported by ships [1] and its share of total anthropogenic emissions is significant, with effects on climate, human health and air quality, especially in coastal areas. Recent studies [2] demonstrated the effectiveness of implementation of the 2005/33/EC European Directive in reducing the impact of ship traffic on aerosol concentrations at local scale, however, the effect on climate is more uncertain. Detailed information regarding the size distribution of the impacts to particles and their correlation with gaseous emissions is needed to investigate the complex air quality-climate interaction of this source. Much of the literature studies focus on NO X , SO 2 , and particulate matter (PM) emissions while there is a gap of knowledge about the size distribution of emitted particles, especially in coarse fraction. This study was done in the framework of POSEIDON (POllution monitoring of Ship Emission: an IntegrateD approach fOr harbour of the Adriatic basiN) project (MED 2007-2013). The aim was to estimate the contribution of in-port ship emissions to gaseous atmospheric pollutants and to PM of different sizes in a port-city in South-Eastern Italy (Adriatic Sea), after the enforcement of the low-sulphur fuel EU-Directive. Measurements were taken at high temporal resolution at the Terminal Passeggeri site in the harbour area of Brindisi (40° 38? 43.32? N-17° 57? 36.39? E). Data collected by a Mobile Laboratory, were gaseous pollutants (NO 2 , NO, O 3 , SO 2 ; 5 min resolution), particle number concentrations (PNC; 1 min resolution), particle size distribution in the range 0.25-32 ?m (1 min resolution) and NO 2 and SO 2 flow-rate emissions with a DOAS (Differential Optical Absorption Spectroscopy) remote-sensing system. The Avvisatore Marittimo provided data of ship traffic in the harbour and a night & day video camera was used to synchronize all measurements and visually estimate number of vehicles (cars, trucks) passing on the framed docks, during phases of loading/unloading of ships at berth. Characterization of ship plumes in aspect of particle size, gaseous concentrations, duration, ratio NO/NO 2 , was performed. The impact analysis [3] was applied separating manoeuvring (arrival/departure of ships) and hotelling (loading/unloading activities) phases. Results showed that the primary contribution to PM 1 and PM 2.5 was significantly lower with respect to those to PNC for both phases, confirming that the majority of the particles emitted were in the ultrafine size range. Manoeuvring phase was characterized by higher impacts to SO 2 , NO, and NO 2 than those to PNC, PM 1 and PM 2.5 . Hotelling phase represented a significant share of the impact for NO, NO 2 , PNC but gave a low contribution to SO 2 impact (due to low-sulphur fuel). Ultrafine particles (D p 1) fraction while accumulation mode particles (0.25

Optical detectors for atmospheric aerosol concentration measurements are often used in air quality applications given their potentialities for online measurements of air quality parameters at high temporal resolution. In this work the performances of different optical aerosol detectors used in air quality applications have been tested and compared for urban background aerosol conditions. Simultaneous measurements of aerosol number concentrations, size distributions and mass concentrations were taken in two different periods: November 2013 – February 2014 and May–June 2014 at an urban background site in Lecce (Southeastern Italy). Measurements were carried out using an OPC Grimm (mod. 1.109), an OPC FAI (Multichannel Monitor) and an optical photometer Mie pDR-1200. Good correlation, with determination coefficients R2 larger than 0.93 were found between particle number concentrations measured by the two OPCs both in accumulation (0.28–0.90 μm for FAI and 0.29–0.90 μm for Grimm) and coarse modes (1.10–10 μm for FAI and 1.15–11.25 μm for Grimm). Absolute counting for the accumulation fraction shows that Grimm OPC detects more particles (about 10%) than FAI OPC at concentration higher than 200,000 particles/L in condition of high RH. This could be due to the changes of the optical properties of particles in high RH conditions visible even if the inlets of the two instruments are conditioned for lowering RH in sampled air. The differences in the absolute counting of the coarse fraction does not seems to be related to RH effects. The performances in evaluating mass concentrations PM10, and PM2.5 were evaluated comparing OPCs and pDR-1200 outputs with reference gravimetric and β-ray methods (that appeared to be essentially equivalent). Good agreement between Grimm OPC and SWAM is found both in PM10 and PM2.5 fractions while FAI OPC revealed greater discrepancy and scatter with respect to reference measurements. The performances of the pDR-1200 photometer were lower with respect to the OPCs with a larger influence of RH and optical properties of particles. The analysis of diurnal average trends in number and mass concentrations as well as the high temporal resolution responses of the instruments showed that optical detectors could be very useful to investigate atmospheric aerosol for air quality applications and to individuate and investigate specific pollution events. However, especially if they are used for evaluating mass concentrations (PM1, PM2.5 or PM10), it is necessary to take into account RH effects (even if the inlet are conditioned) and, possibly, use optical detectors together with reference gravimetric or β-ray methods to check their response in the effective operative conditions.

We present a modelling approach to investigate the impact of ship emissions in the port of Brindisi (IT) on local air quality. The focus is on the impact on pollutant concentrations due to the implementation of the MARPOL Annex VI and the associated NOx technical code 2008 (concerning NOx emissions) and the Directives 2005/33/EU-2012/33/EU (concerning the sulphur content of maritime fuels). Emissions are estimated through an adapted MEET methodology using appropriate emission factors for manoeuvring and hotelling phases. Numerical simulations of NOx, SO2 and primary PM10 are performed by means of the mesoscale model BOLCHEM coupled off-line with ADMS-Urban. The impact of present and future ship emissions on air quality in the port area is evaluated. After the implementation of the Directives 2005/33/EU-2012/33/EU for the year 2012 SO2 showed a significant concentration reduction especially close to the port area, while primary PM10 concentration reduction was minor, as well as that of NOx, as a consequence of the NOx technical code. No significant reductions were found for the year 2020.

Ship emissions are a growing concern, especially in coastal areas, for potential impacts on human health and climate. International mitigation strategies to curb these emission, based on low-sulphur content fuels, have proven useful to improve local air quality. However, the effect on climate forcing is less obvious. Detailed information on the influence of shipping to particles of different sizes is needed to investigate air quality and climate interaction. In this work, the contributions of maritime emissions to atmospheric concentrations of gaseous pollutants (NO, NO2, SO2, and O3) and of particles (sizes from 0.009 mm to 30 mm) were investigated considering manoeuvring (arrival and departure of ships) and hotelling phases (including loading/unloading activities). Results showed that the size distributions of shipping contributions were different for the two phases and could be efficiently described, using measured data, considering four size-ranges. The largest contribution to particles concentration was observed for Dp < 0.25 mm, however, a secondary maximum was observed at Dp ¼ 0.35 mm. The minimum contribution was observed at Dp around 0.8e0.9 mm with a negligible contribution from hotelling for size range 0.4e1 mm. The comparison of 2012 and 2014 datasets showed no significant changes of gaseous and particulate pollutant emissions and of the contribution to particle mass concentration. However, an increase of the contribution to particle number concentration (PNC) was observed. Results suggested that harbour logistic has a relevant role in determining the total impact of shipping on air quality of the nearby coastal areas. Additionally, future policies should focus on PNC that represents an important fraction of emissions also for low-sulphur fuels. DOAS remote sensing proved a useful tool to directly measure NO2 and SO2 ship emissions giving estimates comparable with those of emission inventory approach.