A resistive sensor for humidity detection based on cellulose/polyaniline.

Ambient humidity is an important parameter that affects the manufacturing and storage of several industrial and agricultural goods. In the view of the Internet of Things (IoT), single sensors could be associated with an object for smart monitoring enabling optimum conditions to be maintained. Nevertheless, the production of cost-effective humidity sensors for indoor and outdoor environmental monitoring currently represents the main bottleneck in the development of this technology. Herein we report the results obtained with sensors exclusively made of cellulose and polyaniline (cell/PANI) under strictly controlled relative humidity (30-50 RH%) and temperature (21 ± 1 °C) achieved with a climatic chamber that simulates the conditions of indoor air humidity, and at different RH% in a lab test chamber set-up. Cell/PANI sensors, prepared with a simple, inexpensive, and easily scalable industrial paper process, show a linear trend with a slope of 1.41 µA RH%-1 and a percentage of sensitivity of 13%. Response time as well as percentage of sensitivity results are similar to those of a commercial digital-output relative humidity and temperature sensor (DHT22) employed in parallel for comparison. The commercial sensor DHT22 has a sensitivity of 14%. This low-cost sensor has potential applications in agriculture, food monitoring, and medical and industrial environments as a disposable sensor for humidity detection.

Insight on bacteria communities in outdoor bronze and marble artefacts in a changing environment.

Epilithic bacteria play a fundamental role in the conservation of cultural heritage (CH) materials. On stones, bacterial communities cause both degradation and bioprotection actions. Bronze biocorrosion in non-burial conditions is rarely studied. Only few studies have examined the relationship between bacteria communities and the chemical composition of patinas (surface degradation layers). A better comprehension of bacterial communities growing on our CH is fundamental not only to understand the related decay mechanisms but also to foresee possible shifts in their composition due to climate change. The present study aims at (1) characterizing bacterial communities on bronze and marble statues; (2) evaluating the differences in bacterial communities' composition and abundance occurring between different patina types on different statues; and (3) providing indications about a representative bacterial community which can be used in laboratory tests to better understand their influence on artefact decay. Chemical and biological characterization of different patinas were carried out by sampling bronze and marble statues in Bologna and Ravenna (Italy), using EDS/Raman spectroscopy and MinION-based 16SrRNA sequencing. Significant statistical differences were found in bacterial composition between marble and bronze statues, and among marble patinas in different statues and in the same statue. Marble surfaces showed high microbial diversity and were characterized mainly by Cyanobacteria, Proteobacteria and Deinococcus-Thermus. Bronze patinas showed low taxa diversity and were dominated by copper-resistant Proteobacteria. The copper biocidal effect is evident in greenish marble areas affected by the leaching of copper salts, where the bacterial community is absent. Here, Ca and Cu oxalates are present because of the biological reaction of living organisms to Cu ions, leading to metabolic product secretions, such as oxalic acid. Therefore, a better knowledge on the interaction between bacteria communities and patinas has been achieved.

Chemically and size-resolved particulate matter dry deposition on stone and surrogate surfaces inside and outside the low emission zone of Milan: application of a newly developed "Deposition Box".

The collection of atmospheric particles on not-filtering substrates via dry deposition, and the subsequent study of the particle-induced material decay, is trivial due to the high number of variables simultaneously acting on the investigated surface. This work reports seasonally resolved data of chemical composition and size distribution of particulate matter deposed on stone and surrogate surfaces obtained using a new method, especially developed at this purpose. A "Deposition Box" was designed allowing the particulate matter dry deposition to occur selectively removing, at the same time, variables that can mask the effect of airborne particles on material decay. A pitched roof avoided rainfall and wind variability; a standardised gentle air exchange rate ensured a continuous "sampling" of ambient air leaving unchanged the sampled particle size distribution and, at the same time, leaving quite calm condition inside the box, allowing the deposition to occur. Thus, the "Deposition Box" represents an affordable tool that can be used complementary to traditional exposure systems. With this system, several exposure campaigns, involving investigated stone materials (ISMs) (Carrara Marble, Botticino limestone, Noto calcarenite and Granite) and surrogate (Quartz, PTFE, and Aluminium) substrates, have been performed in two different sites placed in Milan (Italy) inside and outside the low emission zone. Deposition rates (30-90 µg cm-2 month-1) showed significant differences between sites and seasons, becoming less evident considering long-period exposures due to a positive feedback on the deposition induced by the deposited particles. Similarly, different stone substrates influenced the deposition rates too. The collected deposits have been observed with optical and scanning electron microscopes and analysed by ion chromatography. Ion deposition rates were similar in the two sites during winter, whereas it was greater outside the low emission zone during summer and considering the long-period exposure. The dimensional distribution of the collected deposits showed a significant presence of fine particles in agreement with deposition rate of the ionic fraction. The obtained results allowed to point out the role of the fine particles fraction and the importance of making seasonal studies.

Evaluation of the performances of a biological treatment on tin-enriched bronze.

Recently, research gives emphasis to eco-friendly and sustainable approaches for the preservation of cultural heritage that could offer advantages in terms of compatibility, durability and safety. Hence, a biological treatment, based on a specific fungal strain of Beauveria bassiana, is exploited for the stabilization of soluble and/or active bronze corrosion products, converting them into copper oxalates. The chemical stability of the latter represents a real improvement for the long-term preservation of bronze, especially in case of exposure to acid rain. However, the corrosion behaviour of bronze differs from that of pure copper due to the presence of additional alloying elements. In natural environments, the selective dissolution of copper leads to a relative tin-enrichment within the corrosion layers, mostly in unsheltered areas exposed to rainwater runoff. To understand the influence of tin-enrichment on the formation of oxalates, pure tin and artificially tin-enriched bronze coupons were treated with this novel biological system and, in the case of bronze coupons, exposed to accelerated ageing. Tin enrichment and accelerated ageing were performed through runoff tests. Before and after treatment and ageing, the sample surface was characterized through Fourier transform infrared (FTIR) and Raman spectroscopies, scanning electron microscopy coupled to energy dispersive spectroscopy (SEM-EDS). Metals released in the ageing solutions were analysed through atomic absorption spectrometry (AAS). The analytical results allowed to better understand the response of unsheltered areas from outdoor bronze monuments to the biological treatment proposed.

Weathering steel as a potential source for metal contamination: Metal dissolution during 3-year of field exposure in a urban coastal site.

Surface and building runoff can significantly contribute to the total metal loading in urban runoff waters, with potential adverse effects on the receiving ecosystems. The present paper analyses the corrosion-induced metal dissolution (Fe, Mn, Cr, Ni, Cu) from weathering steel (Cor-Ten A) with or without artificial patinas, exposed for 3 years in unsheltered conditions at a marine urban site (Rimini, Italy). The influence of environmental parameters, atmospheric pollutants and surface finish on the release of dissolved metals in rain was evaluated, also by means of multivariate analysis (two-way and three-way Principal Component Analysis). In addition, surface and cross-section investigations were performed so as to monitor the patina evolution. The contribution provided by weathering steel runoff to the dissolved Fe, Mn and Ni loading at local level is not negligible and pre-patination treatments seem to worsen the performance of weathering steel in term of metal release. Metal dissolution is strongly affected by extreme events and shows seasonal variations, with different influence of seasonal parameters on the behaviour of bare or artificially patinated steel, suggesting that climate changes could significantly influence metal release from this alloy. Therefore, it is essential to perform a long-term monitoring of the performance, the durability and the environmental impact of weathering steel.

Source apportionment and location by selective wind sampling and Positive Matrix Factorization.

In order to determine the pollution sources in a suburban area and identify the main direction of their origin, PM2.5 was collected with samplers coupled with a wind select sensor and then subjected to Positive Matrix Factorization (PMF) analysis. In each sample, soluble ions, organic carbon, elemental carbon, levoglucosan, metals, and Polycyclic Aromatic Hydrocarbons (PAHs) were determined. PMF results identified six main sources affecting the area: natural gas home appliances, motor vehicles, regional transport, biomass combustion, manufacturing activities, and secondary aerosol. The connection of factor temporal trends with other parameters (i.e., temperature, PM2.5 concentration, and photochemical processes) confirms factor attributions. PMF analysis indicated that the main source of PM2.5 in the area is secondary aerosol. This should be mainly due to regional contributions, owing to both the secondary nature of the source itself and the higher concentration registered in inland air masses. The motor vehicle emission source contribution is also important. This source likely has a prevalent local origin. The most toxic determined components, i.e., PAHs, Cd, Pb, and Ni, are mainly due to vehicular traffic. Even if this is not the main source in the study area, it is the one of greatest concern. The application of PMF analysis to PM2.5 collected with this new sampling technique made it possible to obtain more detailed results on the sources affecting the area compared to a classical PMF analysis.

Fourteenth National Congress of the Environmental and Cultural Heritage Chemistry Division, "Chemistry in a Sustainable Society," held in Rimini (Italy) in June 2013.

This report briefly presents the aims and the fields of interest of the Environmental and Cultural Heritage Division (Italian Chemical Society) and the issues addressed during its national congress, held in Rimini in June 2013. The broad range of topics raised by different speakers, the variety of affiliations and institutions participating at the conference, the scientific organisations and private companies co-sponsoring the different sessions give a clear picture of the interdisciplinarity which is a hallmark of this division.

The role of angiogenin in pT1-T2 tongue carcinoma neo-angiogenesis and cell proliferation: an exploratory study.

BACKGROUND: Angiogenin (ANG) is a member of the ribonuclease superfamily and of medical interest largely because it supports the growth of primary and metastatic malignancies. This study is the first to investigate the potential role of ANG in tongue carcinoma neo-angiogenesis and cancer cell proliferation. METHODS: Angiogenin expression (in carcinoma cells and endothelial intratumor vessel cells), CD105-assessed micro-vessel density (MVD), and MIB-1 expression were correlated with prognostic parameters in 28 primarily consecutively operated pT1-T2 tongue carcinomas (squamous cell carcinoma [SCC]). Whenever feasible, a computer-based image analysis system was used for the immunohistochemical reaction analysis. RESULTS: No significant correlations emerged between ANG expression in the tongue carcinoma cells or endothelial intratumor vessel cells and tongue SCC recurrence rate or disease-free survival (DFS). ANG expression was also unrelated to CD105-assessed MVD or MIB-1 expression. Conversely, CD105-assessed MVD correlated directly with recurrence rate (P = 0.02) and DFS was significantly shorter in cases with CD105-assessed MVD >167 micro-vessels/mm(2) than in those with CD105-assessed MVD ≤167 micro-vessels/mm(2) (P = 0.042). CONCLUSIONS: Our results support the hypothesis that CD105-assessed MVD would be a valuable parameter for predicting which patients with tongue SCC are at greatest risk of disease recurrence. Despite our study results, the role of ANG in tongue carcinoma warrants further investigation in larger series.

PCDD/Fs atmospheric deposition fluxes and soil contamination close to a municipal solid waste incinerator.

Bulk depositions and surface soil were collected in a suburban area, near the Adriatic Sea, in order to assess the contribution of a municipal solid waste incinerator to the area's total contamination with polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs and PCDFs). Samples were collected at two sites, situated in the area most affected by plant emissions (according to the results of the Calpuff air dispersion model), and at an external site, considered as a reference. Results show that the studied area is subject to low contamination, as far as these compounds are concerned. Deposition fluxes range from 14.3 pg m(-2)d(-1) to 89.9 pg m(-2)d(-1) (0.75 pg-TEQ m(-2)d(-1) to 3.73 pg-TEQ m(-2)d(-1)) and no significant flow differences are observed among the three monitored sites. Total soil concentration amounts to 93.8 ng kg(-1) d.w. and 1.35 ng-TEQ kg(-1)d.w, on average, and confirms a strong homogeneity in the studied area. Furthermore, from 2006 to 2009, no PCDD/Fs enrichment in the soil was noticed. Comparing the relative congener distributions in environmental samples with those found in stack emissions from the incineration plant, significant differences are observed in the PCDD:PCDF ratio and in the contribution of the most chlorinated congeners. From this study we can conclude that the incineration plant is not the main source of PCDD/Fs in the studied area, which is apparently characterized by a homogeneous and widespread contamination situation, typical of an urban area.

Risk assessment applied to air emissions from a medium-sized Italian MSW incinerator.

Risk assessment is a well established procedure for the analysis of the adverse impacts of pollutant substances emitted by waste treatment plants. The aim of the present study was the determination of the impact on human health associated with the activities of an incinerator in the Emilia-Romagna region (Northern Italy). The dispersion of heavy metals and organic pollutants monitored at plant stacks was predicted by the Gaussian model ISC3 (US-EPA). This analysis led to the estimation of risk, connected with various pollutants showing toxic and carcinogenic activities, for different receptors. The values obtained were first compared with the acceptability limits set by US-EPA, and then graphically represented as a territorial dispersion. A cautious approach was followed to calculate risk, by considering the worst, albeit realistic and reliable, estimate for the different parameters. The calculated exposure pathways resulted in different contributions depending on the receptor category (children and adults), even if direct exposure (via inhalation) is generally predominant. However, the resulting risk for both single pollutants studied and their combination all together proved to be within the acceptable limits (all lifetime individual risks being below 10(-6)), according to the procedure followed. The obtained results highlight the importance of using reliable monitoring data on the studied contamination source and, in particular, suggest the advisability of a more in-depth study on the pollution from incineration stacks.

Chemical characterisation of spent rechargeable batteries.

A chemical characterisation of used batteries can give useful information to implement suitable recycling techniques and to estimate the flux of the different materials recovered. This work is aimed to provide quantitative data about the composition of mixed batteries (in particular, Ni-Cd, Ni-MH and Li-ion batteries) collected in a Northern Italian town in order to evaluate the feasibility of recovery processes applied to the selected material. The higher concentration of metals in the <3mm fraction suggested that significant quantities of valuable elements could be recovered: in particular, for a kg of the <3mm fraction deriving from disassembled batteries, about 390 g Ni and 330 g Cd can be recovered from Ni-Cd, 630 g Ni, 80 g Co from Ni-MH and 250 g Co, 110 g Ni, 120 g Cu from Li-ion ones. Leaching tests applied to the same fractions, to assess possible contaminant releases, resulted in low metal content in aqueous solutions (except for Al and Fe, the concentrations of all metals remained below 1mg/kg). Even so, great care is required in all handling activities due to the high pH values of leachate solutions.

Critical loads for Cd and Pb in the province of Bologna.

Atmospheric deposition represents a significant source of heavy metals entering soil and aquatic ecosystems. The evaluation of their vulnerability can be carried out by the Critical Load criterion. In this work we focus the attention on the terrestrial ecosystems in the Province of Bologna, estimating the maximum tolerable load of cadmium and lead they are able to bear without sustain the occurrence of harmful ecotoxicological effects. To this aim the Steady-State Mass Balance method is applied on a small scale (10 x 10 Km EMEP grids) and the more suitable approach to define critical limits for the Province condition, effect-base or stand-still, is discussed. The opportunity of simplifying the input data collection is also considered, trying to deduce soil properties from geological information. Finally, the environmental risk due to the present deposition of Pb and Cd on provincial soils is described as exceedances over the critical loads.

Heavy metals monitoring at a Mediterranean natural ecosystem of Central Italy. Trends in different environmental matrixes.

The study deals with the evaluation of the impact of heavy metal pollution on a Mediterranean natural ecosystem, and presents the results derived from a monitoring of heavy metals in different environmental matrixes (atmospheric dry depositions, suspended particulate matter (SPM) and stemflow of forest trees). Two sites in Castelporziano Presidential Estate (Rome), one internal and one near the sea-side, were chosen in order to assess the differences in pollutant load. Results showed that heavy metal contamination can arise from local anthropogenic activities, in particular road traffic, and long-range pollution, from industrial and artisan activities near Rome.

The atmospheric monitoring in a protected area.

A multi-annual research program was carried out to study the environmental quality of Castelporziano Presidential Estate (Rome, Italy). Within this program, in the field of air quality, a methodological approach was defined and applied, even by means of proper Environmental Indicators for the identification of anthropogenic contribution and the quantification of degradation. By means of mobile laboratories, macro and micro-pollutant concentrations were assessed in order to define Indexes of Atmosphere Quality and Diffuse Contamination, by relating them to possible short or long-range emission sources. Wet and dry atmospheric depositions were collected and analysed for the determination of heavy metal and acid species fluxes. Critical Load and relative Exceedance maps were elaborated, for the purpose of better underline the areas characterized by a higher environmental vulnerability.