Long-term variation in exposure to NO2 concentrations in the city of Naples, Italy: Results of a citizen science project.

The objective of this study is to evaluate long-term changes in the level of exposure to NO2 among the population living in the urban area of Naples (south Italy). This has been achieved by integrating data from the regional reference monitoring network with information collected during the citizen science initiative called 'NO2, NO grazie!' conducted in February 2020 and coordinated by the Non-Governmental Organisation 'Cittadini per l'aria'. This citizen science campaign was based on low-cost passive samplers (Palmes tubes), providing the ability to obtain unprecedented high-resolution NO2 levels. Using a Land Use Random Forest (LURF), we extrapolated the experimental data obtained from the citizen science campaign and evaluated the changes in population exposure from 2013 to 2022 and the uncertainty associated with this assessment was quantified. The results indicate that a large proportion of the inhabitants of Naples are still exposed to high NO2 concentrations, even if strict emission containment measures are enforced. The average levels remain higher than the new interim and air quality targets suggested by the World Health Organisation. The implementation of co-created citizen science projects, where NGO and citizens actively participate alongside scientists, can significantly improve the estimation and the interpretation of official reference data.

Effects of White and Blue-Red Light on Growth and Metabolism of Basil Grown under Microcosm Conditions.

Indoor farming of basil (Ocimum basilicum L.) under artificial lighting to support year-round produce demand is an area of increasing interest. Literature data indicate that diverse light regimes differently affect downstream metabolic pathways which influence basil growth, development and metabolism. In this study, basil was grown from seedlings to fully developed plants in a microcosm, an innovative device aimed at growing plants indoor as in natural conditions. Specifically, the effects of white (W) and blue-red (BR) light under a photosynthetic photon flux density of 255 µmol m-2 s-1 on plant growth, photochemistry, soluble nutrient concentration and secondary metabolism were investigated. Plants grew taller (41.8 ± 5.0 vs. 28.4 ± 2.5 cm) and produced greater biomass (150.3 ± 24.2/14.7 ± 2.0 g vs. 116.2 ± 28.3/12.3 ± 2.5 g fresh/dry biomass) under W light compared to BR light. The two lighting conditions differently influenced the soluble nutrient concentration and the translocation rate. No photosynthetic stress was observed under the two lighting regimes, but leaves grown under W light displayed higher levels of maximum quantum yield of PSII and electron transport rate. Sharp differences in metabolic patterns under the two lighting regimes were detected with higher concentrations of phenolic compounds under the BR light.

A large contribution of methylsiloxanes to particulate matter from ship emissions.

The chemical and stable carbon isotopic composition of the organic aerosol particles (OA) emitted by a shuttle passenger ship between mainland Naples and island Capri in Italy were investigated. Various methylsiloxanes and derivatives were found in particulate ship emissions for the first time, as identified in the mass spectra of a thermal desorption - proton transfer reaction - mass spectrometer (TD-PTR-MS) based on the natural abundance of silicon isotopes. Large contributions of methylsiloxanes to OA (up to 59.3%) were found under inefficient combustion conditions, and considerably lower methylsiloxane emissions were observed under cruise conditions (1.2% of OA). Furthermore, the stable carbon isotopic composition can provide a fingerprint for methylsiloxanes, as they have low δ13C values in the range of -44.91‰ ± 4.29‰. The occurrence of methylsiloxanes was therefore further supported by low δ13C values of particulate organic carbon (OC), ranging from -34.7‰ to -39.4‰, when carbon fractions of methylsiloxanes in OC were high. The δ13C values of OC increased up to around -26.7‰ under cruise conditions, when carbon fractions of methylsiloxanes in OC were low. Overall, the δ13C value of OC decreased linearly with increasing carbon fraction of methylsiloxanes in OC, and the slope is consistent with a mixture of methylsiloxanes and fuel combustion products. The methylsiloxanes in ship emissions may come from engine lubricants.

Chemical characterisation of PM10 from ship emissions: a study on samples from hydrofoil exhaust stacks.

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

Meiofaunal communities and nematode diversity characterizing the Secca delle Fumose shallow vent area (Gulf of Naples, Italy).

Hydrothermal venting is rather prevalent in many marine areas around the world, and marine shallow vents are relatively abundant in the Mediterranean Sea, especially around Italy. However, investigations focusing on the characterization of meiofaunal organisms inhabiting shallow vent sediments are still scant compared to that on macrofauna. In the present study, we investigated the meiobenthic assemblages and nematode diversity inhabiting the Secca delle Fumose (SdF), a shallow water vent area located in the Gulf of Naples (Italy). In this area, characterized by a rapid change in the environmental conditions on a relative small spatial scale (i.e., 100 m), we selected four sampling sites: one diffusive emission site (H); one geyser site (G) and two inactive sites (CN, CS). Total meiofauna abundance did not vary significantly between active and inactive sites and between surface and deeper sediment layers due to a high inter-replicate variability, suggesting a pronounced spatial-scale patchiness in distribution of meiofauna. Nematofauna at site H presented the typical features of deep-sea vents with low structural and functional diversity, high biomass and dominance of few genera (i.e., Oncholaimus; Daptonema) while from site G we reported diversity values comparable to that of the inactive sites. We hypothesized that site G presented a condition of "intermediate disturbance" that could maintain a high nematode diversity. Environmental features such as sediment temperature, pH, total organic carbon and interstitial waters ions were found to be key factors influencing patterns of meiofauna and nematofauna assemblages at SdF. Even though the general theory is that nematodes inhabiting shallow vent areas include a subset of species that live in background sediments, this was not the case for SdF vent area. Due to a marked change in nematode composition between all sites and to the presence of many exclusive species, every single investigated site was characterized by a distinct nematofauna reflecting the high spatial heterogeneity of SdF.

Hybrid Geopolymeric Foams for the Removal of Metallic Ions from Aqueous Waste Solutions.

For the first time, hybrid organic-inorganic geopolymeric foams were successfully used as monolithic adsorbents for the removal of metallic ions pollutants from wastewaters. The foams were realized by the in situ foaming of a hybrid geopolymer obtained by a reaction of metakaolin and polysiloxane oligomers under strong alkaline conditions and then cured at room temperature. In this way, porous materials with densities ranging from 0.4 to 0.7 g/cm3 and showing good mechanical properties were produced. With the aim of producing self-standing monolithic adsorbents for the removal of metallic ions pollutants from wastewaters, these porous hybrid geopolymers were subjected to a washing pretreatment with ultrapure water, dried, and then used for absorption tests by dipping them into an aqueous solution with an initial concentration of 20 ppm of Pb2+, Cd2+, Cu2+, and Zn2+ ions. Preliminary results indicated that all the tested materials are effective in the adsorption of the tested metal ions and do not release the removed metal ions upon sinking in ultrapure water, even for a very long time. Interestingly, compressive strength tests performed before and after the washing treatments show that the foamed samples remain intact and maintain their physical-mechanical characteristics, suggesting that these kinds of materials are promising candidates for the production of self-standing, monolithic adsorbent substrates that can be easily collected when exhausted, which is a major advantage in comparison with the use of powdered adsorbents. Moreover, since these materials can be obtained by a simple and versatile experimental procedure, they could be easily shaped or directly foamed into precast molds to be used in packed beds as membranes.

Hydrates of natural gases and small molecules: structures, properties, and exploitation perspectives.

Starting from the discovery, in the mid-1930s, that petroleum pipelines in the colder regions of the Northern hemisphere contained crusts of some crystals, and were often blocked by them, a short history of the development of research on the structures, properties, and possible exploitation of the class of inclusion compounds known as gas hydrates is given. The state of the assessment of the natural reservoirs and their perspectives for exploitation are presented, together with an analysis of the hypotheses on the origins of the hydrates. Finally, the phase diagrams are shown in relation to environmental problems arising from the instability of the hydrate fields due to global warming or geological activity.