Atmospheric Deposition of Inorganic Elements and Organic Compounds at the Inlets of the Venice Lagoon

The Venice Lagoon is subjected to long-range transport of contaminants via aerosol from the near Po Valley. Moreover, it is an area with significant local anthropogenic emissions due to the industrial area of Porto Marghera, the urban centres, and the glass factories and with emissions by ships traffic within the Lagoon. Furthermore, since 2005, the Lagoon has also been affected by the construction of the MOSE (Modulo Sperimentale Elettromeccanico—Electromechanical Experimental Module) mobile dams, as a barrier against the high tide. This work presents and discusses the results from chemical analyses of bulk depositions, carried out in different sites of the Venice Lagoon. Fluxes of pollutants were also statistically analysed on PCA with the aim of investigating the spatial variability of depositions and their correlation with precipitations. Fluxes of inorganic pollutants depend differently on precipitations, while organic compounds show a more seasonal trend. The statistical analysis showed that the site in the northern Lagoon has lower and almost homogeneous fluxes of pollutants, while the other sites registered more variable concentrations. The study also provided important information about the annual trend of pollutants and their evolution over a period of about five years, from 2005 to 2010

Field study of a soft X-ray aerosol neutralizer combined with electrostatic classifiers for nanoparticle size distribution measurements

Most conventional aerosol neutralizers are based on radioactive sources, which are controlled by strict regulations restricting their handling, transport, and storage. The TSI 3087 soft X-ray (SXR) neutralizer circumvents these legal restrictions. The aim of the present work is to compare the performance of a standalone SXR aerosol neutralizer with that of conventional radioactive aerosol neutralizers based on85Kr (TSI 3077) and241Am (Grimm 5522) by performing field tests in a real environmental scenario. The results obtained when the SXR neutralizer was connected to a mobility particle sizer spectrometer (MPS), different from the device suggested by the manufacturer, were comparable with those obtained with the use of radioactive aerosol neutralizers. In changing the neutralizer, the particle number concentrations, measured with the MPS connected to the SXR neutralizer, almost remained within the 10% uncertainty bounds for the particle size interval 10–300 nm, when diffusion losses inside the SXR tube were considered. Based on our comparisons, the SXR neutralizer can be regarded as a standalone instrument that could solve the problems associated with legal restrictions on radioactive neutralizers and fulfil the need for a portable instrument for different field test purposes

Nano-silver for the treatment of burns: high resolution imaging and speciation in human skin

Dressings coated with silver nanoparticles (AgNPs) are increasingly used in Burns Centres to prevent bacterial infections and favour the regeneration of the damaged tissue. Still, the possible toxicity of AgNPs for patients remains unknown due to the lack of information on their chemical transformations and fate in the human body. Over the last years, we have extensively investigated the metallomics of AgNPs in humans through a number of studies carried out both in vitro and in vivo [3-5]. Here, we present for the first time the high resolution spatial data on silver distribution and speciation in depth profiles of burned skin after application of AgNPs. Full-profile biopsies of the wound were collected from a patient before treatment, and then at 3-days intervals up to the complete healing (12 days). Elemental imaging and μXANES spectra were obtained at the ESRF-ID21 on selected slices from each biopsy. The maps showed that Ag is significantly and rapidly released onto the wound surface, penetrates into the tissue, and accumulates at the borders of the vascular networks characterising the papillary region of dermis. Discharge of the dressing and clearance of Ag mediated by systemic circulation occur also rapidly, making the metal not even detectable into the healed skin after 12 days of treatment. Silver speciation changes with the depth along the profile: the nanoparticles interact with the exudate, the metal being firstly transformed into insoluble chlorides, and then into protein(thiols)-bounded species for mobilization toward the vascularised regions. The data obtained using synchrotron radiation are presented and discussed in the context of a multianalytical integrated approach, including laser ablation-ICP-MS, hydrodynamic HPLC-ICP-MS with single nanoparticle detection mode, TEM, SEM and toxicology tools

Testing nano-silver food packaging to evaluate silver migration and food spoilage bacteria on chicken meat

ABSTRACT Migration of nanomaterials from food containers into food is a matter of concern because of the potential risk for exposed consumers. The aims of this study were to evaluate silver migration from a commercially available food packaging containing silver nanoparticles into a real food matrix (chicken meat) under plausible domestic storage conditions and to test the contribution of such packaging to limit food spoilage bacteria proliferation. Chemical analysis revealed the absence of silver in chicken meatballs under the experimental conditions in compliance with current European Union legislation, which establishes a maximum level of 0.010 mg kg\u20131 for the migration of non-authorised substances through a functional barrier (Commission Regulation (EU) No. 10/2011). On the other hand, microbiological tests (total microbial count, Pseudomonas spp. and Enterobacteriaceae) showed no relevant difference in the tested bacteria levels between meatballs stored in silver-nanoparticle plastic bags or control bags. This study shows the impor- tance of testing food packaging not only to verify potential silver migration as an indicator of potential nanoparticle migration, but also to evaluate the benefits in terms of food preservation so as to avoid unjustified usage of silver nanoparticles and possible negative impacts on the environment

Organ burden and pulmonary toxicity of nano-sized copper (II) oxide particles after short-term inhalation exposure

INTRODUCTION: Increased use of nanomaterials has raised concerns about the potential for undesirable human health and environmental effects. Releases into the air may occur and, therefore, the inhalation route is of specific interest. Here we tested copper oxide nanoparticles (CuO NPs) after repeated inhalation as hazard data for this material and exposure route is currently lacking for risk assessment. METHODS: Rats were exposed nose-only to a single exposure concentration and by varying the exposure time, different dose levels were obtained (C × T protocol). The dose is expressed as 6 h-concentration equivalents of 0, 0.6, 2.4, 3.3, 6.3, and 13.2 mg/m(3) CuO NPs, with a primary particle size of 10 9.2-14 nm and an MMAD of 1.5 μm. RESULTS: Twenty-four hours after a 5-d exposure, dose-dependent lung inflammation and cytotoxicity were observed. Histopathological examinations indicated alveolitis, bronchiolitis, vacuolation of the respiratory epithelium, and emphysema in the lung starting at 2.4 mg/m(3). After a recovery period of 22 d, limited inflammation was still observed, but only at the highest dose of 13.2 mg/m(3). The olfactory epithelium in the nose degenerated 24 h after exposure to 6.3 and 13.2 mg/m(3), but this was restored after 22 d. No histopathological changes were detected in the brain, olfactory bulb, spleen, kidney and liver. CONCLUSION: A 5-d, 6-h/day exposure equivalent to an aerosol of agglomerated CuO NPs resulted in a dose-dependent toxicity in rats, which almost completely resolved during a 3-week post-exposure period

Testing nano-silver food packaging to evaluate silver migration and food spoilage bacteria on chicken meat

<p>Migration of nanomaterials from food containers into food is a matter of concern because of the potential risk for exposed consumers. The aims of this study were to evaluate silver migration from a commercially available food packaging containing silver nanoparticles into a real food matrix (chicken meat) under plausible domestic storage conditions and to test the contribution of such packaging to limit food spoilage bacteria proliferation. Chemical analysis revealed the absence of silver in chicken meatballs under the experimental conditions in compliance with current European Union legislation, which establishes a maximum level of 0.010 mg kg^–1 for the migration of non-authorised substances through a functional barrier (Commission Regulation (EU) No. 10/2011). On the other hand, microbiological tests (total microbial count, <i>Pseudomonas</i> spp. and Enterobacteriaceae) showed no relevant difference in the tested bacteria levels between meatballs stored in silver-nanoparticle plastic bags or control bags. This study shows the importance of testing food packaging not only to verify potential silver migration as an indicator of potential nanoparticle migration, but also to evaluate the benefits in terms of food preservation so as to avoid unjustified usage of silver nanoparticles and possible negative impacts on the environment.</p