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Atmospheric aerosols make significant contributions to several atmospheric chemical and physical processes. Aerosols from anthropogenic emissions have negative impact on air quality and human health. In recent years, significant progress has been made in understanding the anthropogenic pollutants. However, it is still not clear how mixtures of anthropogenic and biogenic emissions impact the regional climate and human health. To better understand aerosol physicochemical properties within the Paris urban plume when mixed with biogenic emissions, a comprehensive airborne measurement platform was deployed in the Île-de-France region in summer 2022 as part of the ACROSS (Atmospheric ChemistRy Of the Suburban foreSt) campaign. In this study, the vertical and spatial distributions of aerosol chemical composition, size distributions, and optical properties during urban plume aging are characterized based on couples of in-situ measurement techniques like aerosol mass spectrometer (c-ToF-AMS), Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) and AVIRAD staged onboard the Safire ATR 42 research aircraft. Gas phase components are also detailed characterized by Proton-transfer-reaction mass spectrometry (PTR-ToF-MS) to act as tracers of anthropogenic and biogenic emissions. Based on gas and particulate phase organic information provided by laser-induced fluorescence technique (TDLIF), the production rate of particulate organic nitrate (pON) can also be estimated. These detailed airborne measurements of aerosol properties provide data that can contribute to modelling studies of aerosol characteristics.

The chemical pathways for the production of secondary organic aerosols (SOA) are influenced by the concentration of nitrogen oxides (NO

The response of the ozone column across Europe to the extreme 2020 Arctic ozone depletion was examined by analyzing ground-based observations at 38 European stations. The ozone decrease at the northernmost site, Ny-Ålesund (79°N) was about 43% with respect to a climatology of more than 30 years. The magnitude of the decrease declined by about 0.7% deg−1 moving south to reach nearly 15% at 40°N. In addition, it was found that the variations of the ozone column at each of the selected stations in March-May were similar to those observed at Ny-Ålesund but with a delay increasing to about 20 days at mid-latitudes with a gradient of approximately 0.5 days deg−1. The distributions of reconstructed ozone column anomalies over a sector covering a large European area show decreasing ozone that started from the north at the beginning of April 2020 and spread south. Such behavior was shown to be similar to that observed after the Arctic ozone depletion in 2011. Stratospheric dynamical patterns in March–May 2011 and during 2020 suggested that the migration of ozone-poor air masses from polar areas to the south after the vortex breakup caused the observed ozone responses. A brief survey of the ozone mass mixing ratios at three stratospheric levels showed the exceptional strength of the 2020 episode. Despite the stronger and longer-lasting Arctic ozone loss in 2020, the analysis in this work indicates a similar ozone response at latitudes below 50°N to both 2011 and 2020 phenomena. An Unprecedented Arctic Ozone Depletion Event During Spring 2020 and Its Impacts Across Europe

The level of environmental microplastics in the sea is constantly increasing. They can enter the human body with food, be absorbed through the gut and have negative effects on the organism’s health after its digestion. To date, microplastics (MPs) are considered new environmental pollutants in the air sea and they are attracting wide attention. The possible toxic effects of MPs isolated at different sea depths of 1, 24 and 78 m were explored in an in vitro model of human gingival fibroblasts (hGFs). MPs isolated from the sea showed different size and were then divided into different sample groups: 1, 24 and 78 m. The results obtained revealed that MPs are able to activate the inflammatory pathway NFkB/MyD88/NLRP3. In detail, the exposure to MPs from 1 and 78 m led to increased levels of inflammatory markers NFkB, MyD88 and NLRP3 in terms of proteins and gene expression. Moreover, cells exposed to MPs showed a lower metabolic activity rate compared to unexposed cells. In conclusion, these findings demonstrate that the inflammation process is stimulated by MPs exposure, providing a new perspective to better understand the intracellular mechanism.

The concentration of nitrogen oxides (NOx) and their reservoir species, the organonitrates (ON), impacts on the secondary organic aerosol (SOA) production. To estimate the effect of different NOx levels on SOA, we carried out a series of laboratory experiments at the Harvard Environmental Chamber (HEC) investigating the production and partitioning of total organonitrates from α-pinene photo-oxidation in a NOx range varying between 1 ppb and 24 ppb. We measured not only the aerosol mass concentration by using a Scanning Mobility Particle Sizer (SMPS) and composition by an on-line aerosol mass spectrometry (AMS), but also the gas phase and particle-phase organonitrates (gON and pON, respectively) by a thermal dissociation laser-induced fluorescence (TDLIF). In our experimental conditions, we found the presence of crossover point of 6 ppb of NOx between clean and polluted conditions that affect the SOA production: in fact, the SOA yield for 1 to 6 ppb NOx increased, and for >6 ppb NOx steadily dropped. The ON partitioning ratio (pON/(pON+gON)) has been estimated, identifying that also this ratio is strongly affected by the NOx concentrations; in fact, it decreased from 0.27 to 0.13 as the NOx increased from

The present study discusses the effect of the ozone depletion that occurred over the Arctic in 2020 on the ozone column in central and southern Europe by analysing a data set obtained from ground-based measurements at six stations placed from 79 to 42°N. Over the northernmost site (Ny-Alesund), the ozone column decreased by about 45% compared to the climatological average at the beginning of April, and its values returned to the normal levels at the end of the month. Southwards, the anomaly gradually reduced to nearly 15% at 42°N (Rome) and the ozone minimum was detected with a delay from about 6 days at 65°N to 20 days at 42°N. At the same time, the evolution of the ozone column at the considered stations placed below the polar circle corresponded to that observed at Ny-Alesund, but at 42°–46°N, the ozone column turned back to the typical values at the end of May. This similarity in the ozone evolutional patterns at different latitudes and the gradually increasing delay of the minimum occurrences towards the south allows the assumption that the ozone columns at lower latitudes were affected by the phenomenon in the Arctic. The ozone decrease observed at Aosta (46°N) combined with predominantly cloud-free conditions resulted in about an 18% increase in the erythemally weighted solar ultraviolet irradiance reaching the Earth’s surface in May.

The novel Coronavirus Disease 2019 (COVID-19) pandemic has renewed attention to aerosol-generating procedures (AGPs). Dental-care workers are at high risk of contamination by SARS-CoV-2. The aim of this study was to evaluate the efficacy of standard saliva ejectors and natural ventilation in reducing particulate matter (PM) concentration during different routine dental procedures in the pandemic period. The DustTrak monitor was used to measure PM1, PM2.5, PM10, and breathable (&lt, 4 microns) total dust during 14 procedures performed with and without the presence of natural ventilation in a dental unit. Moreover, measurements were performed near the practitioners or near the standard saliva ejectors during the different procedures. In the latter condition, reduced levels of PM10 were recorded (82.40 ± 9.65 μg/m3 vs. 50.52 ± 0.23 μg/m3). Moreover, higher levels of PM (53.95 ± 2.29 μg/m3 vs. 27.85 ± 0.14 μg/m3) were produced when the dental unit’s windows were open. At the same time, the total level of PM were higher during scaling than during other procedures (data suggest not to adopt natural ventilation—both window and door opened—during dental procedures). It was also demonstrated that the use of standard saliva ejectors can considerably reduce the total released amount of PM10.

This session will elucidate the role that robust early warning plays in adapting to climate change, via disaster risk reduction and financial services. The session will cover scientific progress relevant to adaptation and resilience, the connection between functional early warning, accurate risk assessment and resilience, and novel financial instruments for risk assessment and disaster risk reduction.

The potential risks of environmental nanoparticles (NPs), in particular Polystyrene Nanoparticles (PNPs), is an emerging problem; specifically, the interaction of PNPs with intestinal cells has not been characterized so far. The mechanism by which polystyrene particles are transferred to humans has not yet been clarified, whether directly through ingestion from contaminated food. We evaluated the interaction between PNPs and colorectal adenocarcinoma cells (HCT116). Cells were exposed to different concentrations of PNPs, metabolic activity and the consequent cytotoxic potential were assessed through viability test; we evaluated the PNP genotoxic potential through the Cytokinesis-Block Micronucleus cytome (CBMN cyt) assay. Finally, we detected Reactive Oxygen Species (ROS) production after NPs exposure and performed Western Blot analysis to analyze the enzymes (SOD1, SOD2, Catalase, Glutathione Peroxidase) involved in the cell detoxification process that comes into play during the cell-PNPs interaction. This work analyzes the cyto and genotoxicity of PNPs in the colorectal HCT116 cell line, in particular the potential damage from oxidative stress produced by PNPs inside the cells related to the consequent nuclear damage. Our results show moderate toxicity of PNPs both in terms of ROS production and DNA damage. Further studies will be needed on different cell lines to have a more complete picture of the impact of environmental pollution on human health in terms of PNPs cytotoxicity and genotoxicity.

This study tests the release of SARS-CoV-2 RNA into the air during normal breathing, without any sign of possible risk of contagion such as coughing, sneezing or talking. Five patients underwent oropharyngeal, nasopharyngeal and salivary swabs for real-time reverse transcriptase PCR (RT-PCR) detection of SARS-CoV-2 RNA. Direct SARS-CoV-2 release during normal breathing was also investigated by RT-PCR in air samples collected using a microbiological sampler. Viral RNA was detected in air at 1 cm from the mouth of patients whose oropharyngeal, nasopharyngeal and salivary swabs tested positive for SARS-CoV-2 RNA. In contrast, the viral RNA was not identified in the exhaled air from patients with oropharyngeal, nasopharyngeal and salivary swabs that tested negative. Contagion of SARS-CoV-2 is possible by being very close to the mouth of someone who is infected, asymptomatic and simply breathing.

One of the fundamental problems of science is the difficulty in understanding the relationships that interconnect consciousness with space and time. The objective of this article is to describe the relationship between consciousness and space-time by relating the Integrated Information Theory (IIT) of Giulio Tononi with the fundamental notions of space and time of the restricted relativity theory. Considering that neuroscience suggests a correlation between consciousness and neural activity, it can be inferred that there is a connection between matter and consciousness and therefore, how the forces interacting with matter can influence consciousness. A further objective is to extend the study of consciousness beyond the skull, to have a mathematical overview describing whether the amount of information produced in the unity of time by a system is stable and absolute or rather whether it depends from the interaction with the space-time and by the speed at which the system moves.

Uno dei problemi fondamentali della scienza è la comprensione della coscienza. In questo testo coscienza e spazio-tempo vengono congiunti in un'unica visione generando una teoria che unisce la Teoria dell'Informazione Integrata (IIT) di Giulio Tononi alle nozioni fondamentali di spazio e tempo derivanti dalla Teoria della Relatività Ristretta. Visto che le neuroscienze suggeriscono una correlazione tra coscienza e attività neurale, si può ipotizzare l'esistenza di una connessione tra materia e coscienza e, di conseguenza, tutte forze che interagiscono con la materia possono influenzare la coscienza. La materia è intesa come un ripiegamento dello spazio-tempo e, quando lo spazio-tempo si deforma in un modo specifico, la coscienza emerge da esso. Poiché lo spazio ed il tempo sono unità relative, anche la coscienza potrebbe avere un'essenza relativa. In altre parole, la coscienza di un sistema non dipende solo dalle sue capacità funzionali, ma anche dalla velocità alla quale si muove nello spazio-tempo. Inoltre, la quantità di coscienza in altri luoghi dell'universo dipende anche dalla velocità alla quale le galassie si espandono

The correlation between SARS-CoV-2 and oral manifestations is still controversial. The aim of this observational study was to determine the oral manifestation of the hospitalized patients for COVID-19. A total of 20 patients met the inclusion criteria and gave their signed informed consent. A questionnaire of 32 questions regarding the oral and systemic health condition was administrated to these patients during the convalescence. A descriptive statistic was performed. Data were analysed through the use of &chi, 2 test, to assess the statistical significance. A statistically significant increase of about 30% of reporting xerostomia during hospitalization was observed (p = 0.02). Meanwhile, a decrease of oral hygiene was observed during the hospitalization, even if a non-statistically significant difference was shown between the two study time points (before and after hospitalization). During the hospitalization period, 25% of patients reported impaired taste, 15% burning sensation, and 20% difficulty in swallowing. An interesting result was that among the systemic conditions, hypertension was observed in 39% of patients and mostly in female patients (62.5%). Further studies are necessary to better understand the symptoms of this new virus in order to faster detect its presence in humans. Probably, a multidisciplinary team following the COVID-19 patients could be of key importance in treating this disease.

The COVID-19 pandemic has affected lives and professions worldwide. We aimed to determine the behavior of dentists during the lockdown in Central Italy through an online survey. We demonstrated that the most frequent of urgencies, not otherwise manageable through telemedicine, was dental pulp inflammation. Although a statistically significant increase in the use of some of the personal protective equipment (PPE) from pre to during lockdown was shown, dentists were afraid of being infected during the dental procedures. Moreover, we showed that digital dentistry, telemedicine, use of the rubber dam, distancing of the appointments and further structural changes at the dental office are necessary to reduce the contagion among dentists and patients. No significant differences were shown between gender.

In July 2017 three research flights circumnavigating the megacity of London were conducted as a part of the STANCO training school for students and early career researchers organised by EUFAR (European Facility for Airborne Research). Measurements were made from the UK's Facility for Airborne Atmospheric Measurements (FAAM) BAe-146-301 atmospheric research aircraft with the aim to sample, characterise and quantify the impact of megacity outflow pollution on air quality in the surrounding region. Conditions were extremely favourable for airborne measurements, and all three flights were able to observe clear pollution events along the flight path. A small change in wind direction provided sufficiently different air mass origins over the 2 d such that a distinct pollution plume from London, attributable marine emissions and a double-peaked dispersed area of pollution resulting from a combination of local and transported emissions were measured. We were able to analyse the effect of London emissions on air quality in the wider region and the extent to which local sources contribute to pollution events.The background air upwind of London was relatively clean during both days; concentrations of CO were 88-95 ppbv, total (measured) volatile organic compounds (VOCs) were 1.6-1.8 ppbv and NOx was 0.7-0.8 ppbv. Downwind of London, we encountered elevations in all species with CO>100 ppbv, VOCs 2.8-3.8 ppbv, CH4> 2080 ppbv and NOx >4 ppbv, and peak concentrations in individual pollution events were higher still. Levels of O-3 were inversely correlated with NOx, during the first flight, with O-3 concentrations of 37 ppbv upwind falling to similar to 26 ppbv in the well-defined London plume. Total pollutant fluxes from London were estimated through a vertical plane downwind of the city. Our calculated CO2 fluxes are within the combined uncertainty of those estimated previously, but there was a greater disparity in our estimates of CH4 and CO.On the second day, winds were lighter and downwind O-3 concentrations were elevated to similar to 39-43 ppbv (from similar to 32 to 35 ppbv upwind), reflecting the contribution of more aged pollution to the regional background. Elevations in pollutant concentrations were dispersed over a wider area than the first day, although we also encountered a number of clear transient enhancements from local sources.This series of flights demonstrated that even in a region of megacity outflow, such as the south-east of the UK, local fresh emissions and more distant UK sources of pollution can all contribute substantially to pollution events. In the highly complex atmosphere around a megacity where a high background level of pollution mixes with a variety of local sources at a range of spatial and temporal scales and atmospheric dynamics are further complicated by the urban heat island, the use of pollutant ratios to track and determine the ageing of air masses may not be valid. The individual sources must therefore all be well-characterised and constrained to understand air quality around megacities such as London. Research aircraft offer that capability through targeted sampling of specific sources and longitudinal studies monitoring trends in emission strength and profiles over time.

This article reports fractal dimension analysis applied to soil CO2 fluxes measured in an Italian seismic area. The work was carried out with the use of a calibrated flux chamber unit. The fractal dimension (FD) from isotropic variograms was used as a method to understand related scale-dependent phenomena. The aim was to investigate the spatial variability of CO2 flux measurements in four directions (horizontal, vertical, 45&deg, and 135&deg, directions) related to different distances between the measuring points and from a fault. High fractal dimension values were found (2.5 &le, FD &le, 3.0). These imply strong anti-persistent behavior near to and far from the fault. Lower fractal dimensions were addressed at longer distances from the fault.

In the framework of the National Project of Interest NextData, we developed automatic procedures for the flagging and formatting of trace gases, atmospheric aerosols and meteorological data to be submitted to the World Data Centers (WDCs) of the Global Atmosphere Watch program of the World Meteorological Organization (WMO/GAW). In particular, the atmospheric Essential Climate Variables (ECVs) covered in this work are observations of near-surface trace gas concentrations, aerosol properties and meteorological variables, which are under the umbrella of the World Data Center for Greenhouse Gases (WDCGG), the World Data Center for Reactive Gases, and the World Data Center for Aerosol (WDCRG and WDCA). We developed an overarching processing chain to create a number of data products (data files and reports) starting from the raw data, finally contributing to increase the maturity of these measurements. To this aim, we implemented specific routines for data filtering, flagging, format harmonization, and creation of data products, useful for detecting instrumental problems, particular atmospheric events and quick data dissemination towards stakeholders or citizens. Currently, the automatic data processing is active for a subset of ECVs at 5 measurement sites in Italy. The system represents a valuable tool to facilitate data originators towards a more efficient data production. Our effort is expected to accelerate the process of data submission to WMO/GAW or to other reference data centers or repositories. Moreover, the adoption of automatic procedures for data flagging and data correction allows to keep track of the process that led to the final validated data, and makes data evaluation and revisions more efficient by improving the traceability of the data production process.

Atmospheric particulate matter (PM) is one of the pollutant that may have a significant impact on human health. Data collected during three years in an urban area of the Adriatic coast are analysed using three models: a multiple linear regression model, a neural network model with and without recursive architecture. Measured meteorological parameters and PM10 concentration are used as input to forecast the daily averaged concentration of PM10 from one to three days ahead. All simulations show that the neural network with recursive architecture has better performances compared to both the multiple linear regression model and the neural network model without the recursive architecture. Results of PM forecasts are compared with the air quality limits for health protection to test the performance as operational tool. The inclusion of carbon monoxide (CO) concentration as further input parameter in the model, has been evaluated in terms of forecast improvements. Finally, all models are used to forecast the PM2.5 concentration, using as input the meteorological data, the PM10 and CO concentration, to simulate the situation when PM2.5 is not observed. The comparison between observed and forecasted PM2.5 shows that the neural network is able to forecast the PM2.5 concentrations even if PM2.5 is not included among the input parameters.

Changes in regional climate are causing disruptions in global agriculture, including wineries that produce premium wines. Temperature is the key factor influencing the growth stages of wine grapes worldwide and its recent increase is causing early harvests, affecting the quality and quantity of premium wine. Water availability is the other important element: during the growing season the crop yield benefits of constant moderate rains, whereas this positive effect would be reversed if the same precipitation amounts fell in short periods of time. Climate change may alter the characteristics of precipitation such as intensity, duration and frequency of rain even if it does not alter the total amount of precipitation. Although the impact of precipitation amount and drought on wine grape phenology have been investigated, knowledge of the role of precipitation characteristics is very limited. Here we show that the precipitation intensity, which is the precipitation amount divided by the number of the rainy days (NRD), has also caused early grape harvest dates for one grape varietal. Using the harvest dates (1820–2012) of a premium wine made by a winery that has kept the cultivation methods and practices unchanged since 1650, we found that for growing seasons since 1960, annual harvest dates have been getting early as temperature increases (−5.92 days °C−1) and more intense precipitation events occur (−1.51 days/(mm/NRD)). Our results are consistent with the hypothesis that the increasing tendency of precipitation intensity could exacerbate the effect of global warming on some premium wines that have been produced for >400 years.

A number of studies have shown variable grades of cytotoxicity and genotoxicity in in vitro cell cultures, laboratory animals and humans when directly exposed to particle debris generated from tires. However, no study has compared the effects of particles generated from passenger tires with the effects of particles from truck tires. The aim of this study was to investigate and relate the cyto- and genotoxic effects of different types of particles (PP, passenger tire particles vs. TP, truck tire particles) in vitro using the phagocytic cell line RAW 264.7 (mouse leukaemic monocyte macrophage cell line). The viability of RAW 264.7 cells was determined by the 3- (4,5-dimethylthiazol-2-yl) -5- (3-carboxymethoxyphenyl) -2- (4-sulfophenyl) -2H-tetrazolium (MTS) assay following exposure for 4, 24 and 48 hours to different particle concentrations (10 μg / ml, 25 μg / ml, 50 μg / ml, 100 μg / ml). The effects of particles of passenger and truck tires on cell proliferation and genotoxicity were evaluated by means of the cytokinesis-block micronucleus (CBMN) assay following exposure for 24 hours to different particle concentrations (10 μg / ml, 25 μg / ml, 50 μg / ml, 100 μg / ml). In MTS assay, after 24 hours, it was found that PP induced a 30% decrease in metabolic activity at a concentration of 10 μg/ml, while TP caused reductions of 20% and 10% at concentrations of 10 μg/ml and 50 μg/ml, respectively. At 48 hours after the treatments, we observed increased metabolic activity at 50 μg/ml and 100 μg/ml for the PP while only at 50 μg/ml for the TP. The CBMN assay showed a significant increase in the number of micronuclei in the cells incubated with PP in all experimental conditions, while the cells treated with TP showed a meaningful increase only at 10 μg /ml. We utilized the TNF-α ELISA mouse test to detect the production of tumour necrosis factor-alpha (TNF-α) in RAW 264.7 cells. The effect of passenger and truck particles on TNF-α release was evaluated following exposure for 4 and 24 hours. After 4 hours of incubation, the cells treated with PP and TP at 100 μg / ml showed a slight but significant increase in TNF-α release, while there was a significant increase in the release of TNF-α after 24 hours of incubation with both tire samples in the cells treated with 50 and 100 μg / ml PP. The data obtained show a higher cytotoxic, clastogenic/genotoxic and inflammatory effects of passenger compared to the truck tire particles.

Several studies have provided information on environmental nanoplastic particles/debris, but the in vitro cyto-genotoxicity is still insufficiently characterized. The aim of this study is to analyze the effects of polystyrene nanoparticles (PNPs) in the Hs27 cell line. The viability of Hs27 cells was determined following exposure at different time windows and PNP concentrations. The genotoxic effects of the PNPs were evaluated by the cytokinesis-block micronucleus (CBMN) assay after exposure to PNPs. We performed ROS analysis on HS27 cells to detect reactive oxygen species at different times and treatments in the presence of PNPs alone and PNPs added to the Crocus sativus L. extract. The different parameters of the CBMN test showed DNA damage, resulting in the increased formation of micronuclei and nuclear buds. We noted a greater increase in ROS production in the short treatment times, in contrast, PNPs added to Crocus sativus showed the ability to extract, thus reducing ROS production. Finally, the SEM-EDX analysis showed a three-dimensional structure of the PNPs with an elemental composition given by C and O. This work defines PNP toxicity resulting in DNA damage and underlines the emerging problem of polystyrene nanoparticles, which extends transversely from the environment to humans, further studies are needed to clarify the internalization process.

One of the fundamental problems of science is the difficulty in understanding the relationships that interconnect consciousness with space and time. The objective of this article is to describe the relationship between consciousness and space-time by relating the Integrated Information Theory (IIT) of Giulio Tononi with the fundamental notions of space and time of the restricted relativity theory. Considering that neuroscience suggests a correlation between consciousness and neural activity, it can be inferred that there is a connection between matter and consciousness and therefore, how the forces interacting with matter can influence consciousness. A further objective is to extend the study of consciousness beyond the skull, to have a mathematical overview describing whether the amount of information produced in the unity of time by a system is stable and absolute or rather whether it depends from the interaction with the space-time and by the speed at which the system moves.

Measurement of NO2 at low concentrations (tens of ppts) is non-trivial. A variety of techniques exist, with the conversion of NO2 into NO followed by chemiluminescent detection of NO being prevalent. Historically this conversion has used a catalytic approach (molybdenum); however, this has been plagued with interferences. More recently, photolytic conversion based on UV-LED irradiation of a reaction cell has been used. Although this appears to be robust there have been a range of observations in low-NOx environments which have measured higher NO2 concentrations than might be expected from steady-state analysis of simultaneously measured NO, O3, jNO2, etc. A range of explanations exist in the literature, most of which focus on an unknown and unmeasured “compound X” that is able to convert NO to NO2 selectively. Here we explore in the laboratory the interference on the photolytic NO2 measurements from the thermal decomposition of peroxyacetyl nitrate (PAN) within the photolysis cell. We find that approximately 5 % of the PAN decomposes within the instrument, providing a potentially significant interference. We parameterize the decomposition in terms of the temperature of the light source, the ambient temperature, and a mixing timescale ( ∼ 0.4 s for our instrument) and expand the parametric analysis to other atmospheric compounds that decompose readily to NO2 (HO2NO2, N2O5, CH3O2NO2, IONO2, BrONO2, higher PANs). We apply these parameters to the output of a global atmospheric model (GEOS-Chem) to investigate the global impact of this interference on (1) the NO2 measurements and (2) the NO2 : NO ratio, i.e. the Leighton relationship. We find that there are significant interferences in cold regions with low NOx concentrations such as the Antarctic, the remote Southern Hemisphere, and the upper troposphere. Although this interference is likely instrument-specific, the thermal decomposition to NO2 within the instrument's photolysis cell could give an at least partial explanation for the anomalously high NO2 that has been reported in remote regions. The interference can be minimized by better instrument characterization, coupled to instrumental designs which reduce the heating within the cell, thus simplifying interpretation of data from remote locations.

In the framework of the National Project of Interest Nextdata, we developed procedures for the automatic flagging and formatting of trace gas, atmospheric aerosol and meteorological data to be submitted to Global Atmosphere Watch programme by the World Meteorological Organization (WMO/GAW). In this work, we describe a first prototype of a centralized system to support Italian atmospheric observatories towards a more efficient and objective data production and subsequent submission to WMO/GAW World Data Centers (WDCs). In particular, the atmospheric variables covered by this work were focused on near-surface trace gases, aerosol properties and (ancillary) meteorological parameters which are under the umbrella of the World Data Center for Greenhouse Gases (WDCGG, see https://ds.data.jma.go.jp/gmd/wdcgg/), World Data Center for Reactive Gases and World Data Center for Aerosol (WDCRG and WDCA, see http://ebas.nilu.no). For different Essential Climate Variables (ECVs), we developed specific routines for data filtering, flagging, format harmonization and creation of data products (i.e. plot of raw and valid-corrected-averaged ECV data and internal instrument parameters) useful for detecting instrumental problems or atmospheric events. A special suite of products based on the temporal aggregation of valid ECV data (like the “calendar” or “timevariation” products) were implemented for quick data dissemination towards stakeholders or citizens Currently, the automatic processing of data is active for a subset of ECVs and 4 measurement sites in Italy. The Nextdata system does not generate “consolidated” data to be directly submitted to WDCs, but it represents a valuable tool to facilitate data providers towards a more efficient data production for those data streams. Our effort is expected to accelerate the process of data submission to GAW/WMO or to other reference data centers or repositories as well as to make the data flagging more “objective”, which means that it is based on a set of well-defined selection criteria and not strictly related to the subjective judgment of station operators. Moreover, the adoption of automatic procedures for data flagging and data correction allows to keep track of the process that led to the final validated data, and makes data evaluation and revisions more efficient.

The Mediterranean basin is considered a global hot-spot region for climate change and air quality, especially concerning summer-time ozone (O3). Previous investigations indicated that the Mediterranean basin is a preferred region for stratosphere-to-troposphere exchange (STE) and deep stratospheric intrusion (SI) events. The Lagrangian tool STEFLUX, based on a STE climatology that uses the ERA Interim data, was hereby used to diagnose the occurrence of deep SI events in four mountain regions over the Italian peninsula, spanning from the Alpine region to the southern Apennines. By using near-surface O3 and relative humidity (RH) observations at three high-mountain observatories, we investigated the performance of STEFLUX in detecting deep SI events. Both experimental and STEFLUX detections agreed in describing the seasonal cycle of SI occurrence. Moreover, STEFLUX showed skills in detecting &ldquo, long-lasting&rdquo, SI events, especially in the Alps and in the northern Apennines. By using STEFLUX, we found positive tendencies in the SI occurrence during 1979&ndash, 2017. However, in contrast to similar studies carried out in the Alpine region, the negative long-term (1996&ndash, 2016) trend of O3 in the northern Apennines did not appear to be related to the SI&rsquo, s variability.

Hourly concentrations of ozone (O 3 ) and nitrogen dioxide (NO 2 ) have been measured for 16 years, from 1998 to 2013, in a seaside town in central Italy. The seasonal trends of O 3 and NO 2 recorded in this period have been studied. Furthermore, we used the data collected during one year (2005), to define the characteristics of a multiple linear regression model and a neural network model. Both models are used to model the hourly O 3 concentration, using, two scenarios: 1) in the first as inputs, only meteorological parameters and 2) in the second adding photochemical parameters at those of the first scenario. In order to evaluate the performance of the model four statistical criteria are used: correlation coefficient, fractional bias, normalized mean squared error and a factor of two. All the criteria show that the neural network gives better results, compared to the regression model, in all the model scenarios. Predictions of O 3 have been carried out by many authors using a feed forward neural architecture. In this paper we show that a recurrent architecture significantly improves the performances of neural predictors. Using only the meteorological parameters as input, the recurrent architecture shows performance better than the multiple linear regression model that uses meteorological and photochemical data as input, making the neural network model with recurrent architecture a more useful tool in areas where only weather measurements are available. Finally, we used the neural network model to forecast the O 3 hourly concentrations 1, 3, 6, 12, 24 and 48 h ahead. The performances of the model in predicting O 3 levels are discussed. Emphasis is given to the possibility of using the neural network model in operational ways in areas where only meteorological data are available, in order to predict O 3 also in sites where it has not been measured yet.

Three years of measurements of aerosol vertical profiles (2007–2009) made at the lidar station of L'Aquila, a site in central Italy that is part of the European Aerosol Research Lidar Network, are studied by means of well-tested radiative transfer models to analyze the radiative impact of mineral dust aerosols transported from the Sahara desert. Sixteen major episodes of desert dust transport are considered; the radiative analysis is conducted in terms of diurnal averages of the top-of-atmosphere radiative flux changes (TOARFC) with respect to a reference “clean” aerosol profile not perturbed by long-range transported desert particles. The aerosol size distribution, needed as an input parameter for the Mie scattering program to obtain single-scattering albedo, asymmetry parameter, and extinction scaling over the whole wavelength spectrum, is obtained from simultaneous surface measurements with a multichannel aerosol spectrometer. The calculated average net TOARFC is +2.3 and +3.0 W/m2 in clear- and total-sky conditions, respectively. Solar, planetary components account for −0.42 and +2.7 W/m2 in clear-sky conditions and +0.93 and +2.1 W/m2 in total-sky conditions, respectively. The large effective radius of these coarse mode soil dust particles (reff = 1.5 µm) makes the longwave planetary component of the TOARFC dominant over the solar component, at least for typical continental surface albedo values (0.18 on average, at L'Aquila). The solar component, however, shows a pronounced sensitivity to the surface albedo and becomes dominant over the longwave component for both an ocean albedo (0.07) and a typical surface-snow albedo (0.4), with TOARFC values of −6.3 and +10.6 W/m2, respectively.

Previous studies show variable ozone cytotoxicity and genotoxicity in cell cultures, laboratory animals and humans directly exposed to tropospheric ozone. The aim of this study was therefore to investigate and compare the cyto and genotoxic effects of ozone using adenocarcinoma human alveolar basal epithelial cells A549 and normal human fibroblasts Hs27. A cell culture chamber with controlled atmosphere (a simulation reactor) was built to inject a flow of 120 ppb of ozone, which is two times the threshold value for the protection of human health, fixed by the EU legislation. Cell proliferation was evaluated by a luminescent cell viability assay while we assessed the genotoxic potential of ozone by the induction of micronuclei as well as evaluating DNA strand breaks by the induction of micronuclei evaluated by means of the cytokinesis-block micronucleus (CBMN) assay as well as evaluating DNA strand breaks by Alkaline Comet Assay (CA) or Comet Assay. A549 cells viability decreases significantly at 24 hours treatment with 120 ppb of O3 while at 48 hours and 72 hours O3 treated cells viability doesn't differ in respect to the control. However a significative decrease of A549 viability is shown at 72 hours vs. 48 hours in both treated and not-treated cells. The viability trend in the Hs27 cells did not show any significant changes in treated samples compared to the control in all conditions. The two genotoxicity biomarkers, the micronucleus and the comet tests, showed in both the cell types exposed to ozone, a significant increase in the number of micronuclei and in the tail DNA % in respect to the control even if at different times/cell type. Moreover, we found that O3 provokes genotoxic effects more evident in A549 cancer cells than in normal fibroblasts Hs27 ones. We applied a cell growth simulation model referred to ozone treated or not cell lines to confirm that the ozone exposure causes a slackening in the cells replication.

Two years of radon-222 observations collected at L’Aquila (Italy) in the atmospheric surface layer during 2004–2006 were analyzed in correlation with meteorological data and other atmospheric tracers. A box model was developed to better understand the mechanisms of diurnal and seasonal variability of the tracer and to indirectly assess the magnitude of the monthly averaged radon soil flux in the L’Aquila measurement site. The model was successfully validated with measurements, with a 0.8 average correlation coefficient between hourly values for the whole period of radon observations. Measurements taken during March 2009 were analyzed to find possible signs of perturbation due to the ongoing seismic activity that would have reached its peak on the 6 April 2009 destructive earthquake. Contrary to the professed (and unpublished) dramatic increases of radon activity unofficially announced to the inhabitants at that time, the study presented here shows that no radon activity increase took place in L’Aquila with respect to a previous ‘seismically unperturbed’ year (same month with similar meteorological conditions), but that an average 30 % decrease was experienced. This conclusion is reached from a direct comparison of observed data and also as a result of the previously validated radon box model constrained by actual meteorological data, from which an indirect estimate of a 17 % reduction of the radon soil flux is obtained.

Surface measurements of multi-channel aerosol mass concentration are analyzed together with LIDAR observations at L'Aquila, a central Italy site part of the EARLINET network ( http://www.earlinet.org/ ), with the main purpose of discriminating aerosol particles originated from in-situ sources and those transported from remote sites, and their effects on local aerosol load and on the aerosol optical depth. Four major episodes of both Saharan desert and forest fire aerosol transport were observed during spring–summer months of 2007. The analysis of these events shows that at the ground surface the aerosol mass concentration increase due to desert dust particles is about 160% of the PMcoarse, whereas forest fires increase the PM 1 by about 150%, with respect to typical reference unperturbed conditions during the same time period. Calculation of the aerosol optical depth (AOD) from the LIDAR retrieved aerosol extinction at 351 nm shows that the corresponding increases in AOD are 95% for Saharan dust and 220% in case of forest fires. These results show that in a site impacted by aerosol transport from the desert and frequent forest fires, the first has the bigger effect in terms of local aerosol load in the coarse mode, whereas the latter impacts more the PM 1 and the UV aerosol extinction and optical depth. A well tested radiative transfer model (TUV, Madronich and Floke, 1998 ), extended to the solar near infrared spectrum, has been used to calculate the top-of-atmosphere radiative change due to these transported aerosols: the calculated change is of the order of 0.5–1 W/m 2 for forest fire events end 1–2 W/m 2 for Saharan dust. The larger impact of desert aerosols is due to their much larger effective radius with respect to forest fire aerosols, whose scattering efficiency rapidly declines for solar wavelengths in the visible and near infrared range.

This paper reports measurements of land–atmosphere fluxes of sensible and latent heat, momentum, CO 2 , volatile organic compounds (VOCs), NO, NO 2 , N 2 O and O 3 over a 30 m high rainforest canopy and a 12 m high oil palm plantation in the same region of Sabah in Borneo between April and July 2008. The daytime maximum CO 2 flux to the two canopies differs by approximately a factor of 2, 1200 mg C m −2 h −1 for the oil palm and 700 mg C m −2 h −1 for the rainforest, with the oil palm plantation showing a substantially greater quantum efficiency. Total VOC emissions are also larger over the oil palm than over the rainforest by a factor of 3. Emissions of isoprene from the oil palm canopy represented 80 per cent of the VOC emissions and exceeded those over the rainforest in similar light and temperature conditions by on average a factor of 5. Substantial emissions of estragole (1-allyl-4-methoxybenzene) from the oil palm plantation were detected and no trace of this VOC was detected in or above the rainforest. Deposition velocities for O 3 to the rainforest were a factor of 2 larger than over oil palm. Emissions of nitrous oxide were larger from the soils of the oil palm plantation than from the soils of the rainforest by approximately 25 per cent. It is clear from the measurements that the large change in the species composition generated by replacing rainforest with oil palm leads to profound changes in the net exchange of most of the trace gases measured, and thus on the chemical composition of the boundary layer over these surfaces.

A laser induced fluorescence (LIF) instrument has been developed to measure tropospheric NO 2 with low detection limit. The instrument design, development and first measurements are reported. There are also details of the temporal gate system built for the fluorescence acquisition. The instrument is able to make fast measurements (up to 4 Hz) and shows a limit of detection of 10 pptv/60 s. Continuous observations (2 weeks in summer 2007) in a small town in central Italy were used to test the performance of the instrument and to study the photochemistry of ozone in a background site. LIF and a commercial chemiluminescence (CL) instrument simultaneous observations of NO 2 show a good linearity (LIF = 1.02 CL + 0.6 (ppb), R 2 = 0.98) but there is a bias of the commercial instrument of about 0.60 ppbv on average. The overestimation of the CL system is probably due to conversion of NO y species into NO by the molybdenum converter used in the CL instrument to detect NO 2 . Analysis of 1 s data is used to test the instrument response and the coupling between nitrogen oxides and ozone.

A summer campaign in Central Italy was carried out to study the impact of fire emissions on the mixing ratios of surface trace gases. Observations with a selective and sensitive instrument that uses the laser induced fluorescence technique for direct measurements of nitrogen dioxide (NO2), show a significant increase of NO2 mixing ratios, in the evening, when a fire plume reached the observations site. The increase of NO2 mixing ratios is well correlated (R=0.83) with that of particulate matter (PM), which is one of the primary product of forest and grassland fires. The tight correlation between NO2 and PM is used to improve the performance of a statistical regression model to simulate the observed O3, and to highlight the effect of fire emissions on the O3 mixing ratios. The statistical regression model of O3 improves in terms of performance (bias reduction of 77% and agreement enhancement of 10% for slope and correlation coefficient) when PM2.5 is included as additional input and proxy of the fire emissions among the usual input parameters (meteorological data and NO2 mixing ratios). A case study, comparing observed and modeled O3 in different days (with and without fire plume), suggests an impact of fire emissions on the O3 mixing ratios of about 10%.