Impacts of air pollution on human and ecosystem health, and implications for the National Emission Ceilings Directive: Insights from Italy.

Across the 28 EU member states there were nearly half a million premature deaths in 2015 as a result of exposure to PM2.5, O3 and NO2. To set the target for air quality levels and avoid negative impacts for human and ecosystems health, the National Emission Ceilings Directive (NECD, 2016/2284/EU) sets objectives for emission reduction for SO2, NOx, NMVOCs, NH3 and PM2.5 for each Member State as percentages of reduction to be reached in 2020 and 2030 compared to the emission levels into 2005. One of the innovations of NECD is Article 9, that mentions the issue of "monitoring air pollution impacts" on ecosystems. We provide a clear picture of what is available in term of monitoring network for air pollution impacts on Italian ecosystems, summarizing what has been done to control air pollution and its effects on different ecosystems in Italy. We provide an overview of the impacts of air pollution on health of the Italian population and evaluate opportunities and implementation of Article 9 in the Italian context, as a case study beneficial for all Member States. The results showed that SO42- deposition strongly decreased in all monitoring sites in Italy over the period 1999-2017, while NO3- and NH4+ decreased more slightly. As a consequence, most of the acid-sensitive sites which underwent acidification in the 1980s partially recovered. The O3 concentration at forest sites showed a decreasing trend. Consequently, AOT40 (the metric identified to protect vegetation from ozone pollution) showed a decrease, even if values were still above the limit for forest protection (5000 ppb h-1), while PODy (flux-based metric under discussion as new European legislative standard for forest protection) showed an increase. National scale studies pointed out that PM10 and NO2 induced about 58,000 premature deaths (year 2005), due to cardiovascular and respiratory diseases. The network identified for Italy contains a good number of monitoring sites (6 for terrestrial ecosystem monitoring, 4 for water bodies monitoring and 11 for ozone impact monitoring) distributed over the territory and will produce a high number of monitored parameters for the implementation of the NECD.

Modeled deposition of nitrogen and sulfur in Europe estimated by 14 air quality model systems: evaluation, effects of changes in emissions and implications for habitat protection.

The evaluation and intercomparison of air quality models is key to reducing model errors and uncertainty. The projects AQMEII3 and EURODELTA-Trends, in the framework of the Task Force on Hemispheric Transport of Air Pollutants and the Task Force on Measurements and Modelling, respectively (both task forces under the UNECE Convention on the Long Range Transport of Air Pollution, LTRAP), have brought together various regional air quality models to analyze their performance in terms of air concentrations and wet deposition, as well as to address other specific objectives. This paper jointly examines the results from both project communities by intercomparing and evaluating the deposition estimates of reduced and oxidized nitrogen (N) and sulfur (S) in Europe simulated by 14 air quality model systems for the year 2010. An accurate estimate of deposition is key to an accurate simulation of atmospheric concentrations. In addition, deposition fluxes are increasingly being used to estimate ecological impacts. It is therefore important to know by how much model results differ and how well they agree with observed values, at least when comparison with observations is possible, such as in the case of wet deposition. This study reveals a large variability between the wet deposition estimates of the models, with some performing acceptably (according to previously defined criteria) and others underestimating wet deposition rates. For dry deposition, there are also considerable differences between the model estimates. An ensemble of the models with the best performance for N wet deposition was made and used to explore the implications of N deposition in the conservation of protected European habitats. Exceedances of empirical critical loads were calculated for the most common habitats at a resolution of 100 × 100 m2 within the Natura 2000 network, and the habitats with the largest areas showing exceedances are determined. Moreover, simulations with reduced emissions in selected source areas indicated a fairly linear relationship between reductions in emissions and changes in the deposition rates of N and S. An approximate 20 % reduction in N and S deposition in Europe is found when emissions at a global scale are reduced by the same amount. European emissions are by far the main contributor to deposition in Europe, whereas the reduction in deposition due to a decrease in emissions in North America is very small and confined to the western part of the domain. Reductions in European emissions led to substantial decreases in the protected habitat areas with critical load exceedances (halving the exceeded area for certain habitats), whereas no change was found, on average, when reducing North American emissions in terms of average values per habitat.

High resolution estimates of the corrosion risk for cultural heritage in Italy.

Air pollution plays a pivotal role in the deterioration of many materials used in buildings and cultural monuments causing an inestimable damage. This study aims to estimate the impacts of air pollution (SO2, HNO3, O3, PM10) and meteorological conditions (temperature, precipitation, relative humidity) on limestone, copper and bronze based on high resolution air quality data-base produced with AMS-MINNI modelling system over the Italian territory over the time period 2003-2010. A comparison between high resolution data (AMS-MINNI grid, 4 × 4 km) and low resolution data (EMEP grid, 50 × 50 km) has been performed. Our results pointed out that the corrosion levels for limestone, copper and bronze are decreased in Italy from 2003 to 2010 in relation to decrease of pollutant concentrations. However, some problem related to air pollution persists especially in Northern and Southern Italy. In particular, PM10 and HNO3 are considered the main responsible for limestone corrosion. Moreover, the high resolution data (AMS-MINNI) allowed the identification of risk areas that are not visible with the low resolution data (EMEP modelling system) in all considered years and, especially, in the limestone case. Consequently, high resolution air quality simulations are suitable to provide concrete benefits in providing information for national effective policy against corrosion risk for cultural heritage, also in the context of climate changes that are affecting strongly Mediterranean basin.

Properties of agricultural aerosol released during wheat harvest threshing, plowing and sowing.

This study shows for the first time a chemical and morphological characterization of agricultural aerosols released during three important agricultural operations: threshing, plowing and sowing. The field campaigns were carried out in the eastern part of the Po Valley, Italy, in summer and autumn 2009. The aerosol particles were sampled on quartz fiber filters and polytetrafluoroethylene membranes in order to allow Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis and Scanning Electron Microscopy equipped with an Energy Dispersive X-ray Spectrometer (SEM-EDS) investigations, respectively. The organic carbon mass concentrations were measured with a Sunset Laboratory Dual-Optical Organic Carbone/Elemental Carbon (OCEC) Aerosol analyzer. The morphological and chemical analyses by SEM-EDS allowed recognizing four main particle classes: organic, silica, calcite and clay minerals. The organic particles contribute to both fine and coarse aerosol fractions up to ca. 50% for all three agricultural activities. This was also confirmed by OCEC analysis for fine fraction. Most of the agricultural aerosols, about 60%, were single particles and the remaining 40% were agglomerations of particles. The ICP-MS results showed that threshing and plowing produce more aerosol particles than sowing, which was characterized by important amounts of clay minerals produced from land soils.

Important source of marine secondary organic aerosol from biogenic amines.

Relevant concentrations of dimethyl- and diethylammonium salts (DMA+ and DEA+) were measured in submicrometer marine aerosol collected over the North Atlantic during periods of high biological activity (HBA) in clean air masses (median concentration (minimum-maximum)=26(6-56) ng m(-3)). Much lower concentrations were measured during periods of low biological activity (LBA): 1 (<0.4-20) ng m(-3) and when polluted air masses were advected to the sampling site: 2 (<0.2-24) ng m(-3). DMA+ and DEA+ are the most abundantorganic species, second only to MSA, detected in fine marine particles representing on average 11% of the secondary organic aerosol (SOA) fraction and a dominant part (35% on average) of the water-soluble organic nitrogen (WSON). Several observations support the hypothesis that DMA+ and DEA+ have a biogenic oceanic source and are produced through the reaction of gaseous amines with sulfuric acid or acidic sulfates. Moreover, the water-soluble fraction of nascent marine aerosol particles produced by bubble-bursting experiments carried out in parallel to ambient aerosol sampling over the open ocean showed WSON, DMA+, and DEA+ concentrations always below the detection limit, thus excluding an important primary sea spray source.

An anion-exchange high-performance liquid chromatography method coupled to total organic carbon determination for the analysis of water-soluble organic aerosols.

The chemical composition of water-soluble organic carbon (WSOC) in atmospheric aerosol particles is largely unexplored, due to the myriad of individual compounds, which has hampered attempts to attain a full characterization at the molecular level. An alternative approach, focusing on the analysis of a few main chemical classes, allowed the quantitative fractionation of WSOC into neutral compounds (NC), mono- and di-acids (MDA) and polyacids (PA) through an anion-exchange liquid chromatographic method. Previous attempts to quantify NC, MDA and PA relied on a low-pressure chromatographic technique using a volatile buffer, followed by total organic carbon (TOC) analysis of the fractions, or alternatively on a faster HPLC-UV method which provided a quantification of the fractions based on empirical relationships between UV signal and TOC concentration. Here, we report an upgraded anion-exchange HPLC technique, allowing direct TOC analysis of the eluted fractions, without any pre-treatment, thus permitting a great simplification of quantitative analysis and preventing sample losses. The new HPLC-TOC methodology, employing completely inorganic eluents shows the same efficiency of the former HPLC-UV method employing organic additives, with the exception of phenolic compounds, which are retained on the column by secondary interactions, and low-molecular weight tricarboxylic acids, which are recovered among MDA. The new anion-exchange liquid chromatographic method can recover a substantial amount (86-100%) of water-soluble organic carbon from atmospheric aerosol extracts, thus allowing a higher retention and fractionation capacity with respect to alternative techniques, like solid phase extraction.

Biogenically driven organic contribution to marine aerosol.

Marine aerosol contributes significantly to the global aerosol load and consequently has an important impact on both the Earth's albedo and climate. So far, much of the focus on marine aerosol has centred on the production of aerosol from sea-salt and non-sea-salt sulphates. Recent field experiments, however, have shown that known aerosol production processes for inorganic species cannot account for the entire aerosol mass that occurs in submicrometre sizes. Several experimental studies have pointed to the presence of significant concentrations of organic matter in marine aerosol. There is some information available about the composition of organic matter, but the contribution of organic matter to marine aerosol, as a function of aerosol size, as well as its characterization as hydrophilic or hydrophobic, has been lacking. Here we measure the physical and chemical characteristics of submicrometre marine aerosol over the North Atlantic Ocean during plankton blooms progressing from spring through to autumn. We find that during bloom periods, the organic fraction dominates and contributes 63% to the submicrometre aerosol mass (about 45% is water-insoluble and about 18% water-soluble). In winter, when biological activity is at its lowest, the organic fraction decreases to 15%. Our model simulations indicate that organic matter can enhance the cloud droplet concentration by 15% to more than 100% and is therefore an important component of the aerosol-cloud-climate feedback system involving marine biota.

Binary homogeneous nucleation in water-succinic acid and water-glutaric acid systems.

Binary homogeneous nucleation of water-succinic acid and water-glutaric acid systems have been investigated. The numerical approach was based on the classical nucleation theory. Usually, nucleation is discussed in terms of kinetics, but the thermodynamics involved is undoubtedly equally important. In this paper we studied the above mentioned binary systems giving a quantitative insight into the nucleation process and a detailed consideration of the thermodynamics involved. Both diacids in study are in solid state at room temperature. They behave in environment according to their liquid state properties because of the absence of crystalline lattice energies, and therefore their subcooled liquid state thermodynamics have to be considered. The lack of consistent thermodynamic data for pure organic components and their aqueous solutions represent a high source of uncertainty. However, the present simulations indicate that in atmospheric conditions these binary systems will not form new particles.