ULTRAFINE PARTICLES IN WORKING ENVIRONMENT AND AMBIENT AIR: REAL-TIME MEASUREMENTS, CHARACTERIZATION AND EVALUATION OF EXPOSURE ROUTES

Ultrafine particles (UFPs) are released in ambient air from natural and anthropogenic sources but also certain workplace conditions are responsible for the unintentional emission of this kind of particles. The small size and corresponding large specific surface area of UFPs and nanoparticles (NPs) are responsible for the great biological activity per given mass. Other specific characteristics of UFPs such as number concentration, shape, agglomeration state and chemical composition play an important role in determining toxicity and reactivity. Even though UFPs represent a major concern in terms of human exposure, excluding some guidelines for workplace air currently there is no legal threshold for controlling them in ambient air. The aim of this thesis is to measure and characterize UFPs that can be found in working environments and ambient air and, afterwards, explore possible exposure routes. UFPs emission from three kinds of industrial processes were investigated in real working conditions by means of real-time measurements of number concentration and size, morpho-chemical characterization and quantitative analysis of metals in airborne and deposited particles. We demonstrated that iron/manganese oxide nanoparticles are the most representative particles released during automatic gas tungsten arc welding (GTAW) of steel. Moreover, despite the respect of the American Conference of Governmental Industrial Hygienists (ACGIH) limits for respirable aluminium, we found that oxy-fuel welding and the die casting production cycle of aluminium-based products involve the release of UFPs with a chemical composition consistent with the raw materials. From our findings, surface and skin contamination seems to be a secondary source of exposure to UFPs, suggesting a possible increased risk in workers mainly for inhalation exposure. Regarding the evaluation of the presence of UFPs in ambient air, a study was performed in proximity of an industrial \u201chot spot\u201d in Servola district in Trieste where an integral cycle steel plant is located. Particle number concentration (PNC) in the range 10-300 nm in \u201cServola\u201d site was about two times higher than \u201cbackground\u201d values. Moreover, an increase of PNC corresponding to a decrease of the particle size and vice versa was observed. In the particulate matter, agglomerates of nanoparticles containing Fe, Zn and Mn were observed by means of a transmission electron microscope coupled with an energy-dispersive X-ray analytical system (TEM-EDS). The contribution of Fe concentration in the PM1 and, in particular, in the particle fraction below 250 nm seems to be not negligible. This result is highly significant from a toxicological point of view. Servola district is densely inhabited and people live very close to the integrated steel plant that is a relevant emission source. Afterwards, nanoparticles compatible with those found in the aforementioned studies were tested in vitro using the method of static Franz diffusion cells in order to explore possible exposure routes. In particular, dermal and meningeal absorption of Al2O3NPs and MnFe2O4NPs respectively were investigated leaning, in both cases, towards a reassuring absorption profile in physiological conditions

Mobility and fate of Thallium and other potentially harmful elements in drainage waters from a decommissioned Zn-Pb mine (North-Eastern Italian Alps)

The potential impact of decommissioned mining areas on the quality of water resources is an issue of major concern for local communities. Acid mine drainage resulting from hydrolysis and oxidation of metal sulphides associated with mineral veins or mining wastes is often responsible for leaching large amounts of potentially harmful elements (PHEs) in solution, which can be dispersed into the surrounding environment and affect the quality of the recipient water bodies. The aim of the present study was to investigate the geochemical properties of the mine drainage waters at the decommissioned Salafossa mine (North-Eastern Italian Alps), to highlight anomalous concentrations of PHEs outflowing from the currently flooded galleries and to elucidate their speciation. In spite of the Zn-Pb sulphides still present in the body ore, there is no evidence of acid drainage waters from the mine galleries as a result of the buffering effect produced by carbonate host rocks. Due to their high mobility, however, Zn and Tl are present in solution mostly in ionic form. Conversely, the less mobile Pb, is referably partitioned in the solid phase. Additionally, the oxidising conditions of the drainage waters also allow the precipitation of some PHEs (As, Cd, Pb, Tl, Zn) in the form of Fe-Mn oxy-hydroxides and carbonates, which accumulate at the bottom of the mine galleries as fine \u201csediments\u201d or concretions. Drainage waters inside the mine were found to be highly enriched in Zn (up to 16 mg L\u20101), Fe (up to 5 mg L\u20101) and Tl (up to 260 \u3bcg L\u20101). Their concentrations, however, are partially diluted in the mine due to a mixing with less mineralised waters before being discharged into the Piave River, the major tributary downstream from the mining area. Although drainage waters are still characterised by high concentrations of Tl (about 30 \u3bcg L\u20101) at their outflow, dilution in the Piave River seems to be the only natural process mitigating the impact of PHEs within the drainage basin

In vitro dermal penetration of nickel nanoparticles.

Nickel nanoparticles (NiNPs) represent a new type of occupational exposure because, due to the small size/high surface, they can release more Ni ions compared to bulk material. It has been reported a case of a worker who developed sensitization while handling nickel nanopowder without precautions. Therefore there is the need to assess whether the skin absorption of NiNPs is higher compared to bulk nickel. Two independent in vitro experiments were performed using Franz diffusion cells. Eight cells for each experiment were fitted using intact and needle-abraded human skin. The donor phase was a suspension of NiNPs with mean size of 77.7 \ub1 24.1 nm in synthetic sweat. Ni permeated both types of skin, reaching higher levels up to two orders of magnitude in the damaged skin compared to intact skin (5.2 \ub1 2.0 vs 0.032 \ub1 0.010 \u3bcg cm(-2), p = 0.006) at 24 h. Total Ni amount into the skin was 29.2 \ub1 11.2 \u3bcg cm(-2) in damaged skin and 9.67 \ub1 2.70 \u3bcg cm(-2) in intact skin (mean and SD, p = 0.006). Skin abrasions lead to doubling the Ni amount in the epidermis and to an increase of ten times in the dermis. This study demonstrated that NiNPs applied on skin surface cause an increase of nickel content into the skin and a significant permeation flux through the skin, higher when a damaged skin protocol was used. Preventive measures are needed when NiNPs are produced and used due to their higher potential to enter in our body compared to bulk nickel

US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

Melanization Affects the Content of Selected Elements in Parmelioid Lichens

Lichens belonging to Parmeliaceae are highly diversified, but most of them share an extremely conserved morpho-chemical trait: the lower cortex is heavily melanised. The adaptive value of this character is still uncertain. Melanins are ubiquitous compounds found in most organisms since they fulfil several biological functions (defence against UV radiation, oxidising agents, and microbial stress, metal complexation, etc.). This work aims to verify whether melanisation can affect the elemental content of lichen thalli. The relative abundance of macro- (Ca, K and S) and micro- (Fe, Mn and Zn) nutrients in melanised and non-melanised pseudotissues of nine species was first evaluated by a non-destructive micro-X-ray fluorescence elemental analysis on either the upper and lower cortex, and on the internal medulla, which was artificially exposed to the mechanical removal of the lower cortex. Afterwards, the total concentration of the same elements was measured in composite samples by inductively coupled plasma atomic emission spectroscopy after acidic digestion. In order to verify whether Fe and Zn are chemically bound to the melanised pseudotissues, a sequential elution experiment was performed on two species: the two-side heavily melanised Melanelixia glabratula and the one-side lightly melanised Punctelia subrudecta. The content of Fe and Zn was higher in the melanised species than in the non-melanised ones. Species deprived of their melanised lower cortex showed a sharp decrease in Fe but not in Zn, suggesting that the melanised lower cortex is involved in Fe complexation, whereas Zn is homogeneously distributed throughout the thallus

3-O-Hydroxytyrosol glucuronide and 4-O-hydroxytyrosol glucuronide reduce endoplasmic reticulum stress in vitro

Endoplasmic reticulum (ER) stress is important for atherosclerosis development and is mediated by the unfolded protein response (UPR). In this work, we synthesized two among the most physiologically-prominent hydroxytyrosol HT hepatic metabolites, i.e. 3-O-HT glucuronide and 4-O-HT glucuronide and we tested their activities on ER stress (in human hepatocarcinoma HepG2 cells), to gain further insight into the cardiopreventive properties of HT, extra virgin olive oil, and the Mediterranean diet. We report that 3-O-HT glucuronide and 4-O-HT glucuronide inhibit tunicamycin-induced ER stress. As compared with the effects of the parent molecule, 3-O-HT glucuronide and 4-O-HT glucuronide at 10 \u3bcM and 25 \u3bcM alone induced a milder change in mRNA expression levels of both CCAAT-enhancer-binding protein homologous protein (CHOP) and glucose regulated protein GRP78 immunoglobulin heavy chain binding protein (BiP). In conclusion, we add further evidence to the hypothesis that the HT intake might be atheroprotective and reiterate the usefulness to preferably use high-quality, high-(poly)phenol extra virgin olive oil as a prominent condiment

Micro-XRF and FT-IR/ATR analyses of an optically degraded ancient document of the Trieste (Italy) cadastral system (1893): A novel and surprising iron gall ink protective action

This paper aims to identify causes and processes of an undesired age-related optical phenomenon in which two kinds of paper \u2013 awhite paper and a green one \u2013 and an iron-gall ink are involved togetherwith unavoidable environmental agents. Documents under examination are dated 1893 and come from the Trieste cadastral system archive (Ufficio del catasto tavolare di Trieste). The green paper, with a high content of lignin and kaolin is a preprinted payment order used in accounting operations and it is adjacent to a white lignin-free paper. Diffused brown stains appear on the white paper mainly from being in prolonged contact with the green one which was handwritten using iron-gall ink. The green page induces a strong browning effect on the contact side of the white one, except for inked areas. The manuscript black lines of the lignin-containing page seem to protect the adjacent surface, where a mirror image appears. A particular type of mirror effect, which we propose to call negative mirror effect, is clearly evidenced. Micro-XRF (micro-X-ray fluorescence spectroscopy) and FT-IR ATR (attenuated total reflectance Fourier transform infrared spectroscopy) techniques were used to achieve information on both diagnostic inorganic and organic components. By way of our chemical model we can hypothesise the migration of oxidised brown low molecular weight extra-cellulose compounds (from lignin and/or hemicelluloses) from green recto to white verso pages. The browning process is only hindered in sharp correspondence with the areas of the green recto folio written with the iron-gall ink: this ink acts as a physical barrier to the migration or, as a second hypothesis, it is able to withhold the mobile organic compounds by way of a specific but still unknown interaction. In the field of scientific research on metal-gall ink corrosion this is a novel, interesting and surprising case of the reverse, in which the ink itself is not the cause of the corrosion, but the unforeseen preventive agent

Nano- and Submicron Particles Emission during Gas Tungsten Arc Welding (GTAW) of Steel: Differences between Automatic and Manual Process

Welding operations originate micro and nanoparticles represented by metal oxides, unoxidized metals and compounds, such as fluorides and chlorides. Welding fumes exposure is associated to lung cancer, chronic bronchitis, asthma and early Parkinson disease. Ultrafine (nanosized) particles in welding fumes are considered a risk factor in terms of occupational exposure: when inhaled, they are efficiently deposited in all regions of the respiratory tract and can translocate to other target organs as brain and systemic circulation. The study of nanoparticles emissions during welding can help to understand effects related also to new-engineered nanoparticles exposure. In our study two real sources of Gas Tungsten Arc Welding (GTAW) fume particles, collected in an automotive plant, were characterized by means of a transmission electron microscope coupled with an energy-dispersive X-ray analytical system (TEM-EDS) and compared to a zone of the plant far from the two sources used as a reference background. The particles sampled during the automatic GTAW process were mainly constituted by iron/manganese oxide with a mean diameter of 47 nm, followed by smaller iron oxide nanoparticles (21 nm). During the manual welding process mostly aggregates with larger diameters that showed an X-ray spectrum characteristic of different kinds of silicates were found. Iron and cobalt oxides nanoparticles were present only inside bigger aggregates mainly composed of aluminum and titanium oxides. This study confirms that welders are exposed to nano- and submicron particles and that iron/manganese oxide nanoparticles are the most representative in automatic process, despite the low concentration of manganese in welding wires (1\u20132%). Our results help to understand hazard related to welding fumes exposure and possible effects of nanoparticles on lung, brain and systemic circulation