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Forty-two samples of feed, saliva, urines, and faeces collected from a cattle farm were investigated with the aim to evaluate the occurrence of glyphosate in faeces, urine and saliva. Glyphosate in the feed was also quantified to understand how it was assimilated by mammals. All cows excreted glyphosate in their faeces at concentrations between 57 and 983 ng g−1. In contrast, only 55% of urine and one sample of saliva tested positive. Most of the feeds demonstrated a non-negligible presence of glyphosate. In particular, a silage containing soybeans from genetically modified cultivation showed a concentration one order of magnitude higher than the other feeds. This study aims to provide the first complete determination of glyphosate in a cattle farm, considering the possible re-entry into the environment through the spreading of liquid and solid sewage and its possible impact on groundwater. [ABSTRACT FROM AUTHOR]

Haloacetic acids (HAAs) are usually taken to be man-made, regularly determined in drinking water as disinfection by-products; yet they have been demonstrated as a probable photooxidation products from atmospheric halogenated hydrocarbons. Here we determined a total of fourteen HAAs, including for the first time iodinated-HAAs, in aerosol samples collected from April to June 2023 at Parco Bissuola (urbanized area of Venice) and Rio Novo (Venice island). The study provides a first insight and source identification about the anthropogenic or natural origin of HAAs. To fulfil this aim, we improved existing methods with a highly sensitive technique by using high pressure anion exchange chromatography coupled to a triple quadrupole mass spectrometer. Five HAAs have been found to be above the detection limits at both sites, and the major source should be attributed to a mixed contribution from atmospheric oxidation of both organic precursor, sea spray and a minor contribution of an external swimming pool located near the Parco Bissuola site. Considering the presence of iodinated HAAs and their cytotoxicity, the present study also provides a basis for the assessment of risks for humans. [Display omitted] • A sensitive method was developed for fourteen HAAs in atmospheric aerosol. • The presence of iodinated organic acids was also evaluated. • Sea spray and atmospheric photo oxidation are the main source of HAAs. • The presence of a swimming pool slightly impacted in the airborne HAAs load. [ABSTRACT FROM AUTHOR]

Abstract Aerosol samples were collected with a high-volume cascade impactor with a 10 day sampling frequency at the Gruvebadet observatory, close to Ny-Ålesund (Svalbard Islands). A total of 42 filters were analyzed for free and combined amino acids, as they are key components of bio-aerosol. This article provides the first investigation of free and combined L- and d -amino acids in Arctic atmospheric particulate matter. The main aim of this study was to determine how these compounds are distributed in size-segregated aerosols after short-range and long-range atmospheric transport and understand the possible sources of amino acids. The total load of free amino acids ranged from 2.0 to 10.8 pmol m−3, while combined amino acids ranged from 5.5 to 18.0 pmol m−3. At these levels amino compounds could play a role in the chemistry of cloud condensation nuclei and fine particles, for example by influencing their buffering capacity and basicity. Free and combined amino acids were mainly found in the fine aerosol fraction (<0.49 μm) and their concentrations could be affect by several sources, the most important of which were biological primary production and biomass burning. Graphical abstract Image 1 Highlights • The article provides information about the presence of amino acids in the Arctic aerosol. • The study identifies mainly the phytoplanktonic bloom and biomass burning as sources. • For the first time free and combined L- and D-amino acids were studied in Arctic aerosol. [ABSTRACT FROM AUTHOR]

Abstract Water soluble organic carbon significantly contributes to aerosol's carbon mass and its chemical composition is poorly characterized due to the huge number of species. In this study, we determined 94 water-soluble compounds: inorganic ions (Cl−, Br−, I−, NO 3 −, SO 4 2−,K+, Mg+, Na+, NH 4 +, Ca2+), organic acids (methanesulfonic acid and C 2 -C 7 carboxylic acids), monosaccharides, alcohol-sugars, levoglucosan and its isomers, sucrose, phenolic compounds, free l - and d -amino acids and photo-oxidation products of α-pinene (cis-pinonic acid and pinic acid). The sampling was conducted using a micro-orifice uniform deposit impactor (MOUDI) at the urban area of Mestre-Venice from March to May 2016. The main aim of this work is to identify the source of each detected compound, evaluating its particle size distribution. Clear differences in size distributions were observed for each class of analyzed compounds. The positive matrix factorization (PMF) model was used to identify six factors related to different sources: a) primary biogenic aerosol particles with particle size > 10 μm; b) secondary sulfate contribution; c) biomass burning; d) primary biogenic aerosol particles distributed between 10 and 1 μm; e) an aged sea salt input and f) SOA pinene. Each factor was also characterized by different composition in waters soluble compounds and different particles size distribution. Graphical abstract Unlabelled Image Highlights • Determination of 94 water soluble compounds in ultrafine, fine and coarse aerosol • Particle size distribution of l - and d -amino acids in urban aerosol • Factor analysis identified different sources for free amino acids and sugars. • Six different sources were identified with positive matrix factorization. • Each identified source had a specific particle size distribution. [ABSTRACT FROM AUTHOR]

Oxidation products of α-pinene represent a fraction of organic matter in the environmental aerosol. α-pinene is one of most abundant monoterpenes released in the atmosphere by plants, located typically in boreal, temperate and tropical forests. This primary compound reacts with atmospheric oxidants, such as O 3 , O 2 , OH radicals and NO x , through the major tropospheric degradation pathway for many monoterpenes under typical atmospheric condition. Although several studies identified a series of by-products deriving from the α-pinene photo-oxidation in the atmosphere, such as pinic and cis-pinonic acid, the knowledge of the mechanism of this process is partially still lacking. Thus, the investigation of the distribution of these acids in the different size aerosol particles provides additional information on this regard. The aim of this study is twofold. First, we aim to improve the existing analytical methods for the determination of pinic and cis-pinonic acid in aerosol samples, especially in terms of analytical sensitivity and limits of detection (LOD) and quantification (LOQ). We even attempted to increase the knowledge of the α-pinene photo-oxidation processes by analysing, for the first time, the particle-size distribution up to nanoparticle level of pinic and cis-pinonic acid. The analysis of aerosol samples was carried out via high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer. The instrumental LOD values of cis-pinonic and pinic acid are 1.6 and 1.2 ng L −1 while LOQ values are 5.4 and 4.1 ng L −1 , respectively. Samples were collected by MOUDI II™ cascade impactor with twelve cut-sizes, from March to May 2016 in the urban area of Mestre-Venice (Italy). The range concentrations in the aerosol samples were from 0.1 to 0.9 ng m −3 for cis-pinonic acid and from 0.1 to 0.8 ng m −3 for pinic acid. [ABSTRACT FROM AUTHOR]

Pesticides play a key-role in the development of the agrifood sector allowing controlling pest growth and, thus, improving the production rates. Pesticides chemical stability is responsible of their persistency in environmental matrices leading to bioaccumulation in animal tissues and hazardous several effects on living organisms. The studies regarding long-term effects of pesticides exposure and their toxicity are still limited to few studies focusing on over-exposed populations, but no extensive dataset is currently available. Pesticides biomonitoring relies mainly on chromatographic techniques coupled with mass spectrometry, whose large-scale application is often limited by feasibility constraints (costs, time, etc.). On the contrary, chemical sensors allow rapid, in-situ screening. Several sensors were designed for the detection of pesticides in environmental matrices, but their application in biological fluids needs to be further explored. Aiming at contributing to the implementation of pesticides biomonitoring methods, we mapped the main gaps between screening and chromatographic methods. Our overview focuses on the recent advances (2016–2021) in analytical methods for the determination of commercial pesticides in human biological fluids and provides guidelines for their application. [Display omitted] • Analytical methods for pesticides biomonitoring need are still lacking. • Pesticides monitoring in biological fluids (BF) relies on chromatographic methods. • Sensing strategies for pesticides determination in BF are urgently required. • BF matrix effects are a bottleneck in the design of new analytical methods. • Combining chromatographic-screening strategies, pesticide biomonitoring is improved. [ABSTRACT FROM AUTHOR]

A single-step protocol was developed for the hydrolytic hydrogenation of microcrystalline cellulose into sorbitol over commercial carbon-supported Ru, in the presence of gaseous CO2 as an acid source and molecular hydrogen as a reductant. Under these conditions, cellulose was first hydrolysed to glucose by reversibly formed carbonic acid in water and then instantaneously hydrogenated on Ru/C. By tuning the reaction parameters, such as temperature, time and the relative pressure of CO2 and hydrogen gas, cellulose was fully converted at 220 °C in 18 h under 30 and 40 bar of H2 and CO2, respectively, with a sorbitol yield of 81%. Blank experiments revealed that without a catalyst and hydrogen, the reaction exhibited <5% conversion and glucose was the only detected product when the reaction was performed under CO2 pressure. XRD measurements on CO2-treated cellulose surprisingly revealed no noticeable changes in the crystallinity index (<10% with respect to microcrystalline cellulose), suggesting that hydrolytic hydrogenation took place on crystalline, not amorphous, cellulose. Furthermore, not only several cellulosic feedstocks, including filter paper, cotton wool, and cotton fiber, but also typical cellulose-based wastes such as a cardboard pizza box were also tested and under the optimized conditions sorbitol was obtained with yields ranging from 56% up to 72% in all cases. No less significant was the Ru/C catalyst stability, which could be recycled at least six times without any noticeable activity loss. [ABSTRACT FROM AUTHOR]

Primary biological aerosol particles and microorganisms are ubiquitous in the atmosphere. Investigations of airborne chemical markers and microbial communities are critical for identifying sources, transport and transformation processes of aerosols. One potential major source of airborne chemical compounds and microbial communities (e.g. L- and D-amino acids, Flavobacteria) could be related to phytoplankton blooms that occur during the spring season in Arctic fjord systems. Here, we conducted a field study in a polar environment to investigate the occurrence in coarse and fine particles of water-soluble compounds (major ions, carboxylic acids and free L- and D-amino acids) and airborne bacterial communities in aerosol samples. The sampling was conducted with a 6 day sampling frequency at the Gruvebadet observatory, close to Ny-Ålesund (Svalbard Islands). Glycine, D-amino acids and C4- organic acids increased during the exponential phase of a marine bloom that occurred in Kongsfjorden and started to drop at the beginning of the main-bloom phase. On the other hand, Polaribacter together with free L-amino acids overlapped with the Chlorophyll a peak and the subsequent decline, and thus might constitute a useful marker for the main-bloom phase. [Display omitted] • Chemical markers and microbial communities in aerosols show seasonal patterns linked to their sources. • D-amino acids could serve as indicators of developing marine blooms. • Polaribacter and L-amino acids as useful markers for the post-bloom phase. [ABSTRACT FROM AUTHOR]

This study presents the year-round variability of the water-soluble fraction of trace elements (wsTE) and rare earth elements (wsREE) among size segregated airborne particulate matter samples collected at Ny-Ålesund in the Svalbard Archipelago from 26 February 2018 to 26 February 2019. Six different aerosol dimensional fractions were collected using a multi-stage Andersen impactor to better understand local and global circulation with the aim of disentangling the source of inorganic tracers from specific natural or anthropogenic sources. The wsTE and wsREE content, especially in the finest fractions in remote areas, is primarily related to long-range transport and it gives valuable information on (1) the global circulation, (2) the natural sources and (3) the contribution of human activities to aerosol composition. A Factor Analysis was applied to the dataset, including levoglucosan and methanesulfonic acid (MSA), to assess the possibility of using certain inorganic tracers as indicators of specific transport events or circulation regimes. We also investigate back-trajectories to determine potential source areas. [ABSTRACT FROM AUTHOR]

Organic acids in aerosols Earth's atmosphere are ubiquitous and they have been extensively studied across urban, rural and polar environments. However, little is known about their properties, transport, source and seasonal variations in the Svalbard Archipelago. Here, we present the annual trend of organic acids in the aerosol collected at Ny-Ålesund and consider their size-distributions to infer their possible sources and relative contributions. A series of carboxylic acids were detected with a predominance of C2-oxalic acid. Pinic acid and cis-pinonic acid were studied in order to better understand the oxidative and gas-to-particle processes occurred in the Arctic atmosphere. Since the water-soluble organic fraction is mainly composed by organic acids and ions, we investigated how the seasonal variation leads to different atmospheric transport mechanisms, focusing on the chemical variations between the polar night and boreal summer. Using major ions, levoglucosan and MSA, the Positive Matrix Factorization (PMF) identified five different possible sources: a) sea spray; b) marine primary production; c) biomass burning; d) sea ice related process and e) secondary products. Unlabelled Image • A year-round record of organic acids was studied in Arctic aerosols. • The study investigates sources and seasonal trend of particulate organic acids. • The study provides an overview of the change of sources throughout the seasons. • PMF defines five sources for low molecular weight organic acids. [ABSTRACT FROM AUTHOR]

The concentrations and particle-size distribution of sugars in Arctic aerosol samples were studied to investigate their potential sources and transport. Sugars are constituents of the water-soluble organic compounds (WSOC) fraction in aerosol particles where some saccharides are used as tracers of Primary Biological Aerosol Particles (PBAPs). Monosaccharides (arabinose, fructose, galactose, glucose, mannose, ribose, xylose), disaccharides (sucrose, lactose, maltose, lactulose), alcohol-sugars (erythritol, mannitol, ribitol, sorbitol, xylitol, maltitol, galactitol) and anhydrosugars (levoglucosan, mannosan and galactosan) were quantified in aerosol samples collected during three different sampling campaigns (spring and summer 2013, spring 2014 and 2015). The mean total concentrations of sugars were 0.4 ± 0.3, 0.6 ± 0.5 and 0.5 ± 0.6 ng m−3 for 2013, 2014 and 2015 spring campaigns, while the mean concentration increased to 3 ± 3 ng m−3 in the summer of 2013. This work identified a reproducibility in the sugars trend during spring, while the summer data in 2013 allowed to us to demonstrate strong local inputs when the ground was free of snow and ice. Furthermore, the study aims to show that the two specific ratios of sorbitol & galactiol to arabinose were diagnostic for the type of biomass that was burnt. This study demonstrates that not only is long-range atmospheric transport significant. But depending on seasonality, local inputs can also play an important role in the chemical composition of sugars in Arctic aerosol. Unlabelled Image • For the first time a broad class of sugars were studied in Svalbard aerosol. • The study provides information about the sources and transport of sugars in Arctic. • The study identifies biomass burning and local terrestrial/sea input as sources. [ABSTRACT FROM AUTHOR]

Summer 2019 is remembered as one of the most intense biomass burning (BB) seasons on record for the Northern Hemisphere. During the MOSAiC expedition, a smoke-dominated layer was identified in the upper troposphere over the North Pole region. The origin of this layer remains unclear, and no evidence has been found to indicate the intrusion of such particles into the Arctic Boundary Layer. The main aim of this work was to evaluate if biomass burning events in the summer 2019 were detectable at Gruvebadet Atmospheric Laboratory, close to Ny-Å lesund (Svalbard Islands) during the second half of 2019. This paper proposes an innovative approach to discriminate biomass burning events based on optical measurements combined with chemical analysis and air mass back-trajectories. Monthly background values of optical coefficients were defined using multi-annual (2018–2021) statistics and twelve possible events were identified. Source apportionment through positive matrix factorization (PMF) identified that the biomass burning factor by PMF accounted for only 2% of the total investigated concentration. The specific biomass burning tracers such as levoglucosan and phenolic compounds were compared with optical measurements and with the PMF results. Air mass trajectory analysis revealed that the early summer fires detected at Ny-Å lesund originated mainly from North America, as also confirmed by the presence of BB factor of PMF, levoglucosan and also vanillic species (softwood combustion tracers). In contrast, the chemical composition and air masses analysis of the highest peak detected in early December suggested residential heating as plausible source, further amplified by the onset of the harsh winter season and the expansion of the polar vortex towards mid-latitudes. • 12 mild pollution events have been identified investigating optical properties. • Biomass burning's contribution accounted for 2% of the total concentration. • Most of the events were detected during the fall. • The latest events in December may have been impacted by emissions from home heating. [ABSTRACT FROM AUTHOR]

A new Continuous Flow Analysis (CFA) system coupled with Fast Liquid Chromatography – tandem Mass Spectrometry (FLC-MS/MS) has been recently developed for determining organic markers in ice cores. In this work we present an upgrade of this innovative technique, optimized for the detection of levoglucosan in ice cores, a crucial tracer for reconstructing past fires. The upgrade involved a specific optimization of the chromatographic and mass spectrometric parameters, allowing for a higher sampling resolution (down to 1 cm) and the simultaneous collection of discrete samples, for off-line analysis of water stable isotopes and additional chemical markers. The robustness and repeatability of the method has been tested by the analysis of multiple sticks of ice cut from the same shallow alpine ice core, and running the system for several hours on different days. The results show similar and comparable trends between the ice sticks. With this upgraded system, a higher sensitivity and a lower limit of detection (LOD) was achieved compared to discrete analysis of alpine samples for levoglucosan measurements. The new LOD was as low as 66 ng L−1, a net improvement over the previous LOD of 600 ng L−1. [Display omitted] • Levoglucosan embedded in ice cores is now detectable in a semi-continuous manner. • CFA – FLC – MS/MS technique ensures high sensitivity and low detection limits. • Levoglucosan detection in alpine ice cores gives valuable insights on past fires. [ABSTRACT FROM AUTHOR]

Open biomass burning (BB) events are a well-known primary aerosol source, resulting in the emission of significant amount of gaseous and particulate matter and affecting Earth's radiation budget. The 2019–2020 summer, known as "Australian Black Summer", showed exceptional duration and intensity of seasonal wildfires, triggered by high temperatures and severe droughts. Since increasing megafires are predicted due to expected climate changes, it is critical to study the impact of BB aerosol on a large scale and evaluate related transport processes. In this study, five aerosol samples (total suspended particles with a diameter >1 μm) were collected during the XXXV Italian Expedition in Antarctica on board of the R/V Laura Bassi from 6th of January to February 16, 2020, along the sailing route from Lyttelton harbor (New Zealand) to Terra Nova Bay (Antarctica). Levoglucosan and its isomers have been analyzed as markers of BB, together with polycyclic aromatic hydrocarbons (PAHs), sucrose and alcohol sugars. Ionic species and carboxylic acids have been analyzed to support the identification of aerosol sources and its aging. Results showed high levoglucosan concentrations (325–1266 pg m−3) during the campaign, suggesting the widespread presence of smoke in the region, because of huge wildfire releases. Backward trajectories indicated the presence of long-range atmospheric transport from South America, probably carrying wildfires plume, in agreement with literature. Regional sources have been suggested for PAHs, particularly for 3–4 rings' compounds; monosaccharides, sucrose, arabitol, and mannitol were related to marine and biogenic contributions. In a warming climate scenario, more frequent and extensive wildfire episodes are expected in Australia, potentially altering albedo, aerosol radiative properties, and cloud interactions. Therefore, it is crucial to strengthens the investigations on the regional climatic effects of these events in Antarctica. [Display omitted] • Biogenic and BB tracers in aerosol from the Southern Ocean were assessed. • BB tracers were ten times higher than their mean values in Antarctic marine aerosol. • Australian Black Summer wildfires influenced Antarctic aerosol composition. • PAHs were only partially related to BB event, also having other regional sources. • Increased frequency of wildfires may impact Antarctic aerosol radiative properties. [ABSTRACT FROM AUTHOR]

This study investigates for the first time the contamination of water and sediment of the Venice Lagoon by twenty Contaminants of Emerging Concern (CECs): three hormones, six pharmaceutical compounds (diclofenac and five antibiotics, three of which are macrolides), nine pesticides (methiocarb, oxadiazon, metaflumizone, triallate, and five neonicotinoids), one antioxidant (BHT), and one UV filter (EHMC). Water and sediment samples were collected in seven sites in four seasons, with the aim of investigating the occurrence, distribution, and possible emission sources of the selected CECs in the studied transitional environment. The most frequently detected contaminants in water were neonicotinoid insecticides (with a frequency of quantification of single contaminants ranging from 73% to 92%), and EHMC (detected in the 77% of samples), followed by BHT (42%), diclofenac (39%), and clarithromycin (35%). In sediment the highest quantification frequencies were those of BHT (54%), estrogens (ranging from 35% to 65%), and azithromycin (46%). Although this baseline study does not highlight seasonal or spatial trends, results suggested that two of the major emission sources of CECs in the Venice Lagoon could be tributary rivers from its drainage basin and treated wastewater, due to the limited removal rates of some CECs in WWTPs. These preliminary results call for further investigations to better map priority emission sources and improve the understanding of CECs environmental behavior, with the final aim of drawing up a site-specific Watch List of CECs for the Venice Lagoon and support the design of more comprehensive monitoring plans in the future. [Display omitted] • The first investigation of twenty CECs in water and sediment of the Venice Lagoon. • The most frequently quantified contaminants in water were neonicotinoids and EHMC. • Estrogens and BHT had the higher quantification frequencies in sediment samples. • The major emission sources turned out to be tributary rivers and treated wastewater. • The study provides baseline knowledge to draft a Watch List for the Venice Lagoon. [ABSTRACT FROM AUTHOR]

Urban areas in mountain environments are generally located on valley floors surrounded by slopes, where mountain orography drives peculiar meteorology and atmospheric circulation. Also, persistent inversion dynamics may occur strongly affecting air pollution. This study characterizes the PM 2.5 pollution in a major city located in an Alpine valley (Belluno, Northeastern Italy) during the cold season (Autumn-Winter). Major particulate species (elemental and organic carbon, major inorganic ions) and minor/trace elements conventionally used as tracers for source apportionment were analyzed, including oxalate and specific PM 2.5 -bound tracers for biomass burning (K+, levoglucosan, mannosan, galactosan) and for primary biogenic organic aerosol (arabitol, mannitol, glucose). PM 2.5 sources are identified through positive matrix factorization and a series of post-processing tools. Results indicate that biomass burning, mostly emitted by residential wood combustion for domestic heating, is the major source (52% PM 2.5 mass concentration), followed by secondary aerosol (21%), biogenic aerosol (20%), traffic (4%), and dust resuspension (3%). The source contributions are assessed by accounting for the local meteorology. Insights into the dispersion or buildup of PM 2.5 sources were then investigated by dispersion normalization. In addition, the possible effects of persistent thermal inversion events were evaluated by assessing the inversion strength from temperature profiles measured at multiple weather stations at different elevations with respect to the source contributions. Beyond the identification of those emission sources requiring further mitigation actions, this study also analyses the potential effects of local meteorology on PM 2.5 pollution. The methodologies applied in this study can be easily adopted to other mountain environments for successful management of air quality. [Display omitted] • PM 2.5 sources identified through PMF in a major city in an Alpine valley. • Biomass burning account for 52% of PM 2.5 , secondary aerosol 21%, biogenic 20%. • Persistent thermal inversion events identified from high-low altitude weather data. • Biomass burning and secondary aerosol were higher in all inversion periods. • Major effort needed to mitigate the biomass burning pollution in mountain valleys. [ABSTRACT FROM AUTHOR]

A chronic toxicity test (21 d exposure) with the model organism Daphnia magna was performed to study the single-compound and combined effects of four fragrance materials (FMs), including musk xylene (MX), Celestolide™ (ADBI), Galaxolide™ (HHCB), and ethylene brassylate (MT). Furthermore, the transcriptional responses of ten target genes related to detoxification, molting and reproduction (DHR96 , P-gp , CYP360A8 , GST , CYP314 , EcRb , Vtg , CAT , GPX , and GCLC) were determined by performing a quantitative real-time polymerase chain reaction (qRT‒PCR) after juvenile D. magna was exposed for 48 h. The results showed that MX, ADBI and HHCB affected development and reproduction after chronic exposure at a concentration of 10 μg L−1. Conversely, MT did not affect reproduction, growth or molting during the 21 d exposure. In juvenile D. magna , gene expression was significantly altered by ADBI (DHR96, CYP260A8, and GCLC) and MX (DHR96 , CYP360A8 , EcRb , Vtg , CYP314 , and GCLC) but not by HHCB. These results suggest that compared to biochemical measures, conventional biological endpoints provide more informative data regarding the effects of this FM. Compared to single substances in the chronic test, the mixture of the four FMs showed effects at lower concentrations and increased gene expression for EcRb and CYP314 during juvenile exposure, indicating a possible additive or synergistic effect of the four FMs compared to single compound exposure. [Display omitted] • Effects of four FMs were studied on biological endpoints and gene expression in Daphnia magna. • MX, ADBI and HHCB led to negative effects on the growth and reproduction. • MT did not affect the investigated biological endpoints. • Gene expression of Daphnia magna juveniles was altered only by MX and ADBI. • Exposure to FMs mixtures showed effects at lower concentrations than exposure to single FM. [ABSTRACT FROM AUTHOR]

The Col Margherita (MRG) Observatory is a high-altitude background station located in the Eastern Italian Alps. Its elevation and distance from major anthropogenic and natural sources make it ideal for monitoring baseline mercury levels and investigating its geochemical cycles. In this work, total gaseous mercury (TGM), ozone (O 3) and meteorological variables were studied to investigate seasonal and diurnal variability of TGM measurements from March 2018 to May 2019. We found that the year-round mean TGM concentration was 1.8 times higher than the annual atmospheric mercury measurements previously reported during the GMOS project at the same measurement site. The seasonal variation of TGM was characterized by high values in spring and summer and lower values in winter. A systematic diel pattern of TGM was obtained, with low concentrations during the daytime and higher concentrations in the late evening. Spatial patterns and temporal changes in TGM, back-trajectories (BTs) and planetary boundary layer (PBL) analysis showed that total gaseous mercury levels were influenced by local meteorology, as well as regional and long-range transport of air masses. The lowest TGM concentrations in winter are associated with high wind speeds, low boundary layer height and cleaner air masses originating from the Western sector. Conversely, the highest TGM concentrations in spring and summer were attributed to polluted air masses passing over North-eastern and Continental Europe and were probably favoured by the higher PBL height. During the snow cover season, investigation of TGM peak events also demonstrated the potential influence of re-emission processes of previously reactive mercury deposition over snow surfaces. [Display omitted] • A one-year record mean TGM concentration at the MRG was higher than other long-term values observed in remote mountain sites. • TGM was characterized by high values in spring and summer and lower values in winter. • A diel trend of TGM was observed, with low concentrations in the daytime and higher concentrations in the late evening. • TGM levels were influenced by local meteorology, as well as regional and long-range transport of air masses. • Analysis of specific atmospheric mercury elevated events (AMEEs) was performed. [ABSTRACT FROM AUTHOR]

The chemical composition of atmospheric aerosol collected at the Col Margherita Atmospheric Observatory (46° 22ˈ 0.059ˈˈ N, 11° 47ˈ 30.911ˈˈ E, 2543 m a.s.l.) was investigated during spring and summer 2018. This is the first study of this area and should lead to a better understanding of the aerosol chemical composition in the Southern slope of the Eastern Italian Alps, with the aim of proposing this high altitude site as a background station. Aerosol samples were analyzed to determine several water soluble components (Cl−, Br−, I−, NO 3 −, SO 4 2−, K+, Mg2+, Na+, NH 4 +, Ca2+), organic acids (methanesulfonic acid and C 2 –C 7 carboxylic acids), monosaccharides, alcohol-sugars, levoglucosan and its isomers, sucrose, phenolic compounds, free L- and D-amino acids and photo-oxidation products of α-pinene (cis-pinonic acid and pinic acid). The majority of the mass concentration is explained by ionic species, but the other investigated compounds allow us to study other processes or identify the potential sources. Carboxylic acids and photochemical products of α-pinene were used to study photochemical or oxidative processes. Biomass burning input was evaluated using two specific classes of biomarkers: anhydrosugars and phenolic compounds, while biogenic inputs were studied using sugars and free amino acids. None of these water soluble organic compounds have been properly investigated previously in alpine sites because their concentrations in aerosol are very low. • Chemical composition of aerosol collected at Col Margherita Atmospheric Observatory. • First investigation of water soluble organic compounds in alpine sites. • Col Margherita Atmospheric Observatory as background site in the Eastern Italian Alps. [ABSTRACT FROM AUTHOR]