Search

Plant protection products (PPPs) play a fundamental role in the maintenance of agricultural fields and private/public green areas, however they can contaminate zones nearby the application point due to wind drift, resuspension, and evaporation. Several studied have deepened the relationship between PPPs and living beings' health, suggesting that these products might have a negative influence. Some PPPs belong to the class of Emergent Contaminants, which are compounds whose knowledge on the environmental distribution and influence is limited. These issues are even more stressed in urban aerosol, due to the high residential density that characterizes this area. Therefore, this study assessed the contamination caused by polar PPPs, such as herbicides (i.e., Glyphosate), fungicides (i.e., Fosetyl Aluminium), and growth regulators (i.e. Maleic Hydrazide), in size-segregated urban aerosol and evaluated their concentration variability with respect to atmospheric parameters (humidity, temperature, rain). Moreover, hypotheses on possible sources were formulated, exploiting also back-trajectories of air masses. A total of six PPPs were found in the samples: glyphosate was more present in the coarse fraction (2.5-10 μm), Fosetyl Aluminium, chlorate and perchlorate were more present in the coarse/fine fractions (10-1 μm), while cyanuric acid and phosphonic acid were mostly concentrated in the fine/ultrafine fractions (<1 μm). While for the first four we suspect of local sources, such as private gardening, the two latter might derive from the entire Po Valley, a highly polluted area in the North of Italy, and from degradation of other substances., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This paper presents the results of simultaneous high time-resolution measurements of biogenic aerosol (methane sulfonic acid (MSA), non-sea salt sulfate nss SO42-) with its gaseous precursor dimethylsulfide (DMS), performed at the Italian coastal base Mario Zucchelli Station (MZS) in Terra Nova Bay (MZS) during two summer campaigns (2018–2019 and 2019–2020). Data on atmospheric DMS concentration are scarce, especially in Antarctica. The DMS maximum at MZS occurs in December, one month earlier than at other Antarctic stations. The maximum of DMS concentration is connected with the phytoplanktonic senescent phase following the bloom of Phaeocystis antarctica that occurs in the polynya when sea ice opens up. The second plankton bloom occurs in January and, despite the high dimethylsufoniopropionate (DMSP) concentration in seawater, atmospheric DMS remains low, probably due to its fast biological turnover in seawater in this period. The intensity and timing of the DMS evolution during the two years suggest that only the portion of the polynya close to the sampling site produces a discernible effect on the measured DMS. The closeness to the DMS source area and the occurrence of air masses containing DMS and freshly formed oxidation products allow us to study the kinetic of biogenic aerosol formation and the reliable derivation of the branch ratio between MSA and nss SO42- from DMS oxidation that is estimated to be 0.84±0.06. Conversely, for aged air masses with low DMS content, an enrichment of nss SO42- with respect to MSA, is observed. We estimate that the mean contribution of freshly formed biogenic aerosol to PM 10 is 17 % with a maximum of 56 %. The high contribution of biogenic aerosol to the total PM 10 mass in summer in this area highlights the dominant role of the polynya on biogenic aerosol formation. Finally, due to the regional and year-to-year variability of DMS and related biogenic aerosol formation, we stress the need for long-term measurements of seawater and atmospheric DMS and biogenic aerosol along the Antarctic coast and in the Southern Ocean. [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]

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]