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Potentially toxic elements (PTEs) in urban soil environments pose a noticeable risk to both ecosystem and human health; however, only a fraction of the elemental content is available for biota. To better know the potential risk of PTEs in the urban soil environment, geochemical fractionation, bioaccessibility, and potential bioavailability of four PTEs (Cd, Cu, Pb, and Zn) were investigated by the combined use of different methods. The results showed that a high non-residual chemical fraction is related to a high bioavailability of the selected elements. The ranges of labile concentration of Cu, Zn, Cd and Pb in all sampling sites measured by diffusive gradients in thin films (DGT) were 3.5-18.0, 14.2-26.5, 0.09-1.0, and 1.8-15.7 μg/L, respectively. The high non-residual contents pointed out a serious hazard to the urban environment. The bioaccessible concentrations in gastric and lung phases were closely positively correlated with DGT-measured content (r = 0.63-0.99, p0.05), suggesting the potential use of DGT for the prediction of PTEs risk to human health. Moreover, the correlation of DGT results with the soluble and reducible fractions of PTEs may allow DGT use for quick screenings of the PTEs fraction potentially mobilizable during flooding events in urban soil environments. Our study suggests that combing DGT, bioaccessibility and biogeochemical fractionation could provide a more accurate assessment of the urban environmental quality and be helpful for pollution control and urban planning.

The current paper reports the scientific, technical, environmental, economic and social impacts of two integrated chemical and biochemical processes that employed a novel virtuous biowaste cycle under real operational conditions of three industrial sites in Italy, Greece and Cyprus. The work was based on previous laboratory research pertinent to the valorisation of municipal biowastes (MBWs) as a feedstock to obtain value added soluble biobased (SBO) products. The research pointed out that the site-specific nature of MBW was the main criticality, which could potentially hinder the industrialisation of the MBW-SBO paradigm. The present work demonstrates the feasibility of a new scenario for a conventional waste treatment plan collecting and processing MBWs by anaerobic and aerobic fermentation. In essence, the virtuous biowaste cycle is realised by producing SBO from the plant MBW (process 1) and recirculating it to the MBW feed of the anaerobic fermentation reactor to reduce the ammonia content in the digestate (process 2). This mitigates the digestate's environmental impact. Life cycle sustainability assessment demonstrates that the use of SBO produced from local MBW allowed reducing the ammonia content of the digestate generated from the local anaerobic fermentation facilities in the three different countries by 21–68% as well its eutrophication potential. Process 2 allowed at least 86% OPEX cost saving compared to conventional digestate post-treatment technologies for ammonia abatement, while paying off the CAPEX cost in less than one year. Socio-economic analysis evaluated the impacts on workers and local community stakeholders, potentially stemming from the implementation of processes 1 and 2 at European level. The analysis of SBO composition and performances in each operational site investigated showed that improved performance of process 2 might be achieved by isolating the active principles in raw SBO prior to their use in process 2. Chemical and biochemical catalysis by SBO active principles in process 2 support the specific perspective.

Mineral wastes coming from demolition activities, including rock and soil from excavations, and extractive industry, represent the first and the second source of waste production at EU level (35.9% and 26.6% respectively). Although some of these waste products can cause environmental and economic problems if not adequately managed and disposed, they represent an alternative resource for civil, building, infrastructure and environmental applications. This study introduces the state of the art of the research and applications of products arising from mineral waste, with a focus on new potential application of fine fractions for artificial substrate production. The agronomic characteristics of the produced mixes were tested to evaluate their use and the environmental criticalities for land rehabilitation. The results showed that, when mixed with organic materials, the overall quality and fertility of the mineral waste fine fraction was improved, and that this mixture was not phytotoxic. This indicates that when properly managed and treated the mineral waste fine fraction could be effectively employed for land rehabilitation. In general, both coarse and fine mineral waste fractions are valuable alternative construction materials for buildings infrastructures and environmental applications. Sustainable and circular management of mineral waste contributes to guarantee raw materials supply, contemporary reducing environmental (including CO2 production) impacts associated to waste management and landfilling. The potential decrement of environmental impacts and CO2 production will contribute to enhance the NET-zero greenhouse gas emissions EU strategy. Statement of Novelty The present research outlines the possible reuses of different mineral wastes coming from demolition activities and rocks and soils from excavation works as a replacement for natural aggregates, in line with the circular economy paradigm. These materials represent the first source of wastes (in mass) in Europe and innovative processes for their efficient reutilization are needed. This research addressed the main problems connected with their management, focusing on some experimental processes, such as the production of artificial substrates, as a sustainable alternative to contrast the land consumption. However, the updating of the current legislation and the inclusion of these new products for public works (Green Procurement) is regarded fundamental to the effective application of novel technologies.

Mining activities are one of the main contributors to metals contamination of soils, most often due to the inappropriate management of the mining residues. In Italy, hundreds of small mining sites are scattered around the mountainous areas, near small villages with fragile environments. Here, wastes and residues may have polluted the surrounding soils and become a threat to living organisms. We investigated two dismissed sites in Northern Italy with extractive wastes in unmanaged areas close to villages using bioaccessibility and size fractionation methods, focussing on particles that can potentially be eroded and/or ingested (

This work addresses environmental problems connected with biowaste management, the chemical industry, and agriculture. These sectors of human activity cause greenhouse gas (GHG) emissions in the air, climate change, leaching of excess mineral fertilizers applied to soil into ground water, and eutrophication. To mitigate this problem in agriculture, controlled release fertilizers (CRFs) are made by coating mineral fertilizers granules with synthetic polymers produced from the fossil-based chemical industry. This strategy aggravates GHG emission. In the present work, six formulations containing sunflower protein concentrate (SPC) and a new biopolymer (BP) obtained from sunflower oil cake and by hydrolysis of municipal biowaste, respectively, and commercial urea were tested as CRFs for spinach cultivation against the control growing substrate Evergreen TS and commercial Osmocote®. The results show large differences in plants’ nitrate concentration due to the different treatments, although the same nitrogen amount is added to the substrate in all trials. BP is the key component mitigating nitrate accumulation in plants. The plants grown in the substrates containing BP together with SPC and/or urea, although exhibiting relatively high total N uptake (47–52 g kg−1), have significantly lower nitric to total N ratio (9.6–12.0) than that (15.3–16.5) shown by the plants grown in the substrates containing SPC and/or urea, but no BP. The data confirm that all composites containing BP yield the safest crop coupled with high biomass production. Replication of BP effects for the cultivation of different plants will contribute to the development of a biobased chemical industry exploiting biowastes as feedstock.

Lead (Pb) contamination is one of the most significant exposure hazards to human health. Contaminated soil particles may be eroded and transferred either to the atmosphere (10 μm) or to streams; or they may be incidentally ingested (200 μm). Among strategies for the long-term management of this risk, one of the most cost-effective is the reduction of Pb mobility and bioavailability via amendment with phosphorus-containing materials. To clarify the effectiveness of P amendment in reducing Pb mobility and bioaccessibility in different soil size fractions, an experiment was performed by adding a soluble P compound to a historically contaminated urban soil (RO), a mining soil (MI), and an uncontaminated spiked soil (SP) at different P:Pb molar ratios (2.5:1, 5:1, and 15:1). In the10 μm fraction of soils, P addition reduced bioaccessible Pb only in the SP soil at the highest dose, with little to no effect on RO and MI soils. Similarly, in the coarse fraction, Pb was immobilized only in the SP soil with all three P doses. These results were probably due to the higher stability of Pb in historically contaminated soils, where Pb dissolution is the limiting factor to the formation of insoluble Pb compounds. The bioaccessible proportion of Pb (using SBET method) was higher than 70 % of the total Pb in all soils and was similar in both fine and coarse particle fractions. Due to the enrichment of Pb in finer particles, this implies possible adverse effects to the environment or to human health if these particles escape from the soil. These results call for increasing attention to the effect of remediation activities on fine soil particles, considering their significant environmental role especially in urban and in historically low or moderately contaminated areas.

Soil can be resuspended in the atmosphere due to wind or mechanical disturbances, such as agricultural activities (sowing, tilling, etc.), producing fine particulate matter (PM). Agriculture is estimated to be the third PM

Controlled-release fertilizers (CRF) are needed under current agriculture practice to decrease the environmental impact caused by fertilizer doses applied in excess of plants&rsquo, uptake rate. Commercial CRF are available. They are manufactured from mineral fertilizers encapsulated into a synthetic polymer matrix or coated by a polymer layer. However, substitution of fossil sourced organic polymers with biopolymers is a major environmental concern. In the present paper, we describe the manufacture by a continuous twin-screw extrusion process, and the mechanical and chemical properties of injection-molded composite pellets containing 90% sunflower protein concentrate (SPC) matrix, and 5&ndash, 10% of a biopolymer (BP) obtained from municipal biowastes (MBW), and/or urea (U). The reported results show that SPC-BP-U behaves as an efficient eco-friendly CRF. BP contributes to several benefits to the performance of the composite pellets, upon increasing surface hardness, and controlling the formation of ammonia from urea hydrolysis and the release of organic nitrogen. The SPC-BP-U appears a powerful eco-friendly CRF to supply organic C and the three major N, P, and K nutrients to soil and plants. It offers worthwhile scope for being tested in the cultivation of specific plants under the real operational conditions of agriculture practices.

Soil can be resuspended in the atmosphere due to wind or mechanical disturbances, such as agricultural activities (sowing, tilling, etc.), producing fine particulate matter (PM). Agriculture is estimated to be the third PM10-emitting sector in Europe, emitting more than the transportation sector. However, very few emission figures are available for the different cropping operations. Moreover, soil Emission Potential (EP) is extremely variable, since is influenced by factors such as humidity, texture, chemical composition, and wind speed. Due to their similarity to tilling emission mechanisms, Soil Resuspension Chambers (SRC) are the most suitable method to estimate the impacts of these factors on soil susceptibility to emit PM10 during cropping operations (Emission Potential, EP). The main objective of this work is to assess the EP of different agricultural soils used for maize cropping in North-Western Italy, studying the influence of soil moisture and physico-chemical characteristics. Therefore, a SRC was developed, based on previous studies, with the goal of being relatively small, easy to operate and low-cost. Using the gathered data, a log-linear multiple regression model was developed to allow soil EP estimation from few physico-chemical parameters (moisture, sand/silt ratio and organic carbon content). The model allows to tailor field Emission Factors (EF) of specific cropping operations to different soil and moisture conditions and was applied to an EF for rotary harrowing, defined in a previous study. The concentration of Potentially Toxic Elements (PTE) in soil-emitted PM10 was determined, founding an enrichment up to 16 times higher than in the original soil, evidencing a possible cause of concern for operator's safety during agricultural activities.

A new eco-friendly process is reported, the implementation of which at the EU level could reduce ammonia and greenhouse gas emissions from fermented biowaste by over 1 Gt yr-1. The present work reports the case study of municipal biowaste (MBW). The process is based on the use of soluble bio-organic substances (SBOs) as auxiliaries in the anaerobic fermentation of MBW to produce biogas and digestate with reduced ammonia content. The SBO-assisted process enables a virtuous biowaste cycle, where MBW is sequentially fermented under anoxic conditions, the digestate is composted, and the compost generated is hydrolyzed, yielding SBO, which is recycled to the anaerobic fermentation reactor at 0.2% concentration. The results show that depending on the MBW source, fermentation inoculum, and SBO concentration in the fermentation slurry, about 40% reduction of ammonium in the digestate is achieved, whereas the control fermentation without SBO exhibits up to 11% ammonia increase. The microbial community and biogas production are not significantly affected by SBO addition. The data are consistent with biological and chemical processes occurring in SBO-assisted fermentation. These comprise ammonia production by protein hydrolysis catalyzed by proteolytic bacteria and ammonia oxidation to N2 catalyzed by SBOs. The results confirm the benefit provided by the use of SBOs to reduce the environmental impact of biowaste. These encourage the implementation of SBO-assisted fermentation in the real operational environment.

The waste rock, tailings and soil around an abandoned mine site in Gorno (northwest Italy) contain elevated concentrations of potentially toxic elements (PTE) exceeding the permissible limits for residential uses. Specifically, the maximum concentrations of As, Cd, Pb, and Zn were 107 mg/kg, 340 mg/kg, 1064 mg/kg, and 148 433 mg/kg, respectively. A site-specific human health risk assessment (HHRA) was conducted for residential and recreational exposure scenarios, using an approach based on Risk Based Corrective Action (RBCA) method, refined by incorporating oral bioaccessibility data. Oral bioaccessibility analyses were performed by simulating the human digestion process in vitro (Unified BARGE Method). Detailed analysis of oral bioaccessible fraction (BAF i.e. ratio of bioaccessible concentrations to total concentrations on 1) for 50% of the samples, indicating potential human health risks. This study provides information for site-specific risk assessments and planning future research.

Particulate matter (PM) is an air pollutant which poses a considerable risk to human health. The agricultural sector is responsible of the 15% of the total anthropogenic emissions of PM

In this research, fifteen potentially toxic elements (PTEs) (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Sc and Zn) were analysed and quantified in samples collected at 44 sites in an urban area of Iran. Sources were apportioned using enrichment factors (EFs), modified pollution index (MPI), principal component analysis (PCA), multivariate linear regression of absolute principal component scores (MLR-APCS) and speciation, with a focus on anthropogenic PTEs in the urban and industrial soils of the Arvand Free Zone area, an oil-rich zone in the country. Furthermore, the bioaccessibility and the human health risks of PTEs were investigated. The EF revealed a significant enrichment for elements such as Cd, Cu, Hg, Mo, Pb, Sb and Zn. Values of MPI showed that Abadan industrial district and Abadan petrochemical complex are the most polluted sites in the study area.The PCA/MLR analysis revealed four main sources: natural sources, fossil fuel combustion, traffic and oil derivatives and petroleum waste. The relative contribution of each source to PTE concentration varied from 32.3% of the natural sources to 30.6% of traffic and from 20.1% of petroleum waste to 17% of fossil fuel combustion. The source apportionment of metals generated using MLR-APCS receptor modelling revealed that 85.0% of Hg was generated by oil products. Chemical speciation results were compatible with the results obtained from PCA. Bioaccessibility of PTEs decreased from gastric to intestinal phase except Mo and Sb due to their different geochemical characteristics. Hazard index (HI) for non-cancer risk of PTEs for both children and adults based on total element concentrations was estimated to range from 2-fold to more than 10-fold higher than that of bioaccessible phases.

The relative impact of non-exhaust sources (i.e. road dust, tire wear, road wear and brake wear particles) on urban air quality is increasing. Among them, road dust resuspension has generally the highest impact on PM concentrations but its spatio-temporal variability has been rarely studied and modeled. Some recent studies attempted to observe and describe the time-variability but, as it is driven by traffic and meteorology, uncertainty remains on the seasonality of emissions. The knowledge gap on spatial variability is much wider, as several factors have been pointed out as responsible for road dust build-up: pavement characteristics, traffic intensity and speed, fleet composition, proximity to traffic lights, but also the presence of external sources. However, no parameterization is available as a function of these variables. We investigated mobile road dust smaller than 10 μm (MF10) in two cities with different climatic and traffic conditions (Barcelona and Turin), to explore MF10 seasonal variability and the relationship between MF10 and site characteristics (pavement macrotexture, traffic intensity and proximity to braking zone). Moreover, we provide the first estimates of emission factors in the Po Valley both in summer and winter conditions. Our results showed a good inverse relationship between MF10 and macro-texture, traffic intensity and distance from the nearest braking zone. We also found a clear seasonal effect of road dust emissions, with higher emission in summer, likely due to the lower pavement moisture. These results allowed building a simple empirical mode, predicting maximal dust loadings and, consequently, emission potential, based on the aforementioned data. This model will need to be scaled for meteorological effect, using methods accounting for weather and pavement moisture. This can significantly improve bottom-up emission inventory for spatial allocation of emissions and air quality management, to select those roads with higher emissions for mitigation measures.

Road dust (RD), together with surface soils, is recognized as one of the main sinks of pollutants in urban environments. Over the last years, many studies have focused on total and bioaccessible concentrations while few have assessed the bioaccessibility of size-fractionated elements in RD. Therefore, the distribution and bioaccessibility of Fe, Mn, Cd, Cr, Cu, Ni, Pb, Sb and Zn in size fractions of RD and roadside soils (2.5μm, 2.5-10μm and 10-200μm) have been studied using aqua regia extraction and the Simple Bioaccessibility Extraction Test. Concentrations of metals in soils are higher than legislative limits for Cu, Cr, Ni, Pb and Zn. Fine fractions appear enriched in Fe, Mn, Cu, Pb, Sb and Zn, and 2.5-10μm particles are the most enriched. In RD, Cu, Pb, Sb and Zn derive primarily from non-exhaust sources, while Zn is found in greater concentrations in the2.5μm fraction, where it most likely has an industrial origin. Elemental distribution across soils is dependent on land use, with Zn, Ni, Cu and Pb being present in higher concentrations at traffic sites. In addition, Fe, Ni and Cr feature greater bioaccessibility in the two finer fractions, while anthropic metals (Cu, Pb, Sb and Zn) do not. In RD, only Zn has significantly higher bioaccessibility at traffic sites compared to background, and the finest particles are always the most bioaccessible;90% of Pb, Zn and Cu is bioaccessible in the2.5μm fraction, while for Mn, Ni, Sb, Fe and Cr, values vary from 76% to 5%. In the 2.5-10μm fraction, the values were 89% for Pb, 67% for Zn and 60% for Cu. These results make the evaluation of the bioaccessibility of size-fractionated particles appear to be a necessity for correct estimation of risk in urban areas.

Metal-contaminated mining soils pose serious environmental and health risks if not properly managed, especially in mountainous areas, which are more susceptible to perturbation. Currently, climate change is leading to more frequent and intense rain events, which cause flooding episodes, thereby altering soil redox equilibria and contaminants stability. We evaluated the potential release of Zn and Cd (two of the most common inorganic contaminants) and the factors regulating their solubility and speciation in two heavily contaminated soils representative of a Zn-mining area. The soils were flooded under aerobic (for 24 h) and anaerobic (for 62 days) conditions using mesocosm experiments, sequential extractions, and geochemical modelling. Leaching trials under aerobic conditions showed a high release of Zn and Cd (10 times the legislative limits), with metals possibly migrating via water infiltration or runoff. Under anaerobic conditions Zn and Cd were initially released. Then, solution concentrations decreased gradually (Zn) or sharply (Cd) until the end of the experiment. Sequential extractions and multisurface modelling indicated that both metals precipitated mainly as carbonates. This was confirmed by a geochemical multisurface modelling, which also predicted the formation of sulphides after 60 days in one soil. The model calculated metals to be preferentially complexed by organic matter and well predicted the observed soil solution concentrations. The results showed that during flooding episodes contaminants could be promptly transferred to other environmental compartments. The use of multisurface modelling coupled with laboratory experiments provided useful indications on the potential release and speciation in case of anoxic conditions. Electronic supplementary material The online version of this article (10.1007/s00244-020-00777-0) contains supplementary material, which is available to authorized users.

The management of residual sludge from dimension stone processing activities (EWC 010,413) represents a large concern for stone industry. Such sludges are characterised by a fine size distribution, high heavy metal contents and, potentially, TPH (Total Petroleum Hydrocarbon) contents. The objects of the present study are represented by gang-saw with abrasive shot (GSS), diamond frame-saw (DSS) and mixed (MS) sludges. The first one is high in Cr, Ni, Cu and TPH, the second presents high contents in Co, Cr and TPH, and the third represents a mix of the first two ones. Present legislation indicates that they can be disposed of in landfills or can be recovered (R5-R10) as filling material for environmental rehabilitation or as feeding materials for cement production. The sampled materials were obtained from the Verbano Cusio Ossola (VCO) and Luserna Stone quarry basins (Piedmont, Northern Italy). These materials were physically and chemically characterised, and magnetic separation was performed to rapidly evaluate the heavy metal contents in the sludge. Afterwards, three different experiments were carried out for environmental and civil applications. The first one, for substrate production, was carried out using GSS, DSS and MS from VCO area. The second one, for CLSM and plaster production, was performed on materials from VCO and Luserna stone quarry basins (CLSM using GSS from VCO and plaster using DSS from Luserna stone quarry basin). The results here reported are promising for the three applications.

16 páginas.-- 7 figuras.-- 5 tablas.-- 54 referencias.-- The online version of this article ( https://doi.org/10.1007/s11270-019-4101-5) contains supplementary material, which is available to authorized users., Urban soil contamination may represent an environmental threat in view of their proximity to humans. The ecological homogenization of urban areas has been postulated, and as the sources of pollution are the same in most European cities, it is possible that soil contamination is another factor of convergence. The current climate change with consequent increase of extreme rain events may affect the mobility of potentially toxic elements (PTE) thus increasing the risks. If the soil is submerged, Eh decreases and causes the solubilization of Fe and Mn oxides, which are important carriers of PTE. We compared the release of Cu, Pb, and Zn from 48 soils of four cities (namely Glasgow, Ljubljana, Sevilla, and Torino) when submerged for up to 30 days. A decrease of the redox potential was observed in all soils after a few days and an increase of Mn and then Fe in solution. Cu, Pb, and Zn were consequently released to the solution according to the general soil contamination. Despite the marked differences in soil properties, the reaction to anaerobiosis appeared to be similar in all samples indicating that waterlogging of urban soil contaminated with PTE may pose a serious environmental risk and substantiating the hypothesis of ecological convergence, This work was conducted with the financial support of the European Commission, URBSOIL project, under contract EVK4-CT-2001-00053

The results on elemental composition of aerosol (PM10) sampled during 2011 in Piedmont region (Italy) are interpreted using meteorological data, Enrichment Factors (EF), chemometric processing by Principal Component Analysis (PCA), Factor Analysis (FA) and Hierarchical Cluster Analysis (HCA). Daily concentrations of about 30 elements were measured using HR-ICP-MS in five monitoring sites. A clear seasonal pattern, with higher concentrations in autumn and winter, was observed, particularly in the urban sites. Levels of As, Cd, Ni and Pb in most of the samples were within the limits imposed by the European legislation. Spatial differences in PM10 and metal concentrations were significant, with rural and urban sites showing different metal patterns, indicating different sources. K and Ca were used, respectively, as marker of biomass burning and industrial marker (cement plant); EFs showed that Ca was enriched just in one area and K was enriched only in the winter period considered and in some stations. Data analysis through PCA, FA and HCA allowed us to identify correlations among the investigated elements and similarities between sampling sites in order to individuate specific emission sources, such as non-exhaust vehicle emission.

While exposure to traffic pollutants significantly decreases with distance from the curb, very dense urban architectures hamper such dispersion. Moreover, the building height reduces significantly the dispersion of pollutants. We have investigated the horizontal variability of Black Carbon (BC) and the vertical variability of NO2 and BC within the urban blocks. Increasing the distance from road BC concentrations decreased following an exponential curve reaching halving distances at 25 m (median), although with a wide variability among sites. Street canyons showed sharper fall-offs than open roads or roads next to a park. Urban background concentrations were achieved at 67 m distance on average, with higher distances found for more trafficked roads. Vertical fall-off of BC was less pronounced than the horizontal one since pollutants homogenize quickly vertically after rush traffic hours. Even shallower vertical fall-offs were found for NO2. For both pollutants, background concentrations were never reached within the building height. A street canyon effect was also found exacerbating concentrations at the lowest floors of the leeward side of the road. These inputs can be useful for assessing population exposure, air quality policies, urban planning and for models validation.

Although the overall toxicity of bulk atmospheric particles is well known, researchers and air quality managers still face difficulties in the understanding of the most harmful species and sources, which is based on the knowledge of their individual impact on PMx levels. This chapter aims at reviewing the current knowledge of the impact on air quality of vehicle non-exhaust sources (as a whole and individually for road dust, brake wear, tire wear, and road wear). Ninety-nine peer-reviewed articles were found providing contributions ranges, often in comparison with vehicle exhaust contributions. The variability of contributions was explored relatively to particulate matter size fraction, type of location, and climate.

Dust is a mixture of natural and anthropogenic particles originated from multiple sources, which can represent an hazard for human health. Playgrounds are a site of particularly concern, due to sand dust ingestion by toddlers and inhalation. In this study, 37 sands used in public playgrounds in the city of Barcelona were physico-chemically characterized also in relation to routine maintenance activities such as disinfection and sand renewal. The analyzed sands show a felsic mineralogy dominated by Na-feldspar, quartz, and, to a lesser extent, K-feldspar, with minor amounts of clay minerals, carbonates and hematite. Particle fractions below 10, 2.5 and 1 μm represent, on average, 0.65%, 0.17% and 0.07% of bulk volume, respectively, although, due to the human grinding, these initial fractions increased every year by a 18%, 5% and 2% respectively. Disinfection of sands effectively reduced only the NH4+ concentration, among inorganic species. The average metal content was anthropogenically enriched, with respect to the upper continental crust, only for Sb and As. Both elements show high spatial variation indicating local sources such as road traffic for Sb (contributing mostly to the total concentration), and industry for As (also contributing with highly bioaccessible Sb, Cu and Zn). A clear inverse relationship between total concentrations of some elements and their leachable (Sb) and bioaccessible (Sb and Cr) fractions is observed. The most bioaccessible elements were Ca > Ni > Cu > Sr > Cd > Pb, all above the 25% of the total concentration. Bioaccessibility was higher for the carbonate-bearing particles and for the anthropic emitted metals (>50% of Ba, Cu, K, Pb and Zn).

Road dust suspension is an increasing concern in terms of being a source of atmospheric particulate matter (PM) in cities, due to its toxicity and the lack of knowledge on emission estimates, impact and mostly with respect to measures to control or mitigate it. Both technological and policy measures have been proposed, but their application is limited by the gap of knowledge on their effectiveness in the real world. This study analyses the real-world emission factors of road dust at ten sites in the city of Milan (Italy), with an emphasis on the impact of different fleet speeds at one particular road. PM10 emission factors were estimated by means of both the EPA method (based on silt loadings) and the vertical profile of dust deposition. Road dust silt loadings varied within 0.006-0.066 g m-2, with the highest loadings found at sites affected by construction works. Typical urban roads were found to have fleet-averaged emission factors within 13-32 mg vehicle-1 km-1, which is in the central range of the literature values in Europe. The emission factors estimated by means of the vertical profile approach were within 19-26 mg VKT-1, which agree quite well with the EPA method if corrected for speed. In fact, a power-law relation was found between fleet speed and emission factor estimates, with an exponent close to 1.5 for speeds within 36-57 km h-1. These results suggest that the limitation of the maximum traffic speed can be effective for mitigating road dust emissions in cities. © Taiwan Association for Aerosol Research., This study was funded by the Milan Council (Ambiente e Territorio s.r.l., AMAT) and the Italian Ministry of the Environment.

Oral bioaccessibility and solid phase distribution of potentially toxic elements (PTE) from extractive waste streams were investigated to assess the potential human health risk posed by abandoned mines. The solid phase distribution along with micro-X-ray fluorescence (micro-XRF) and scanning electron microscopy (SEM) analysis were also performed. The results showed that the total concentrations of PTE were higher in

Mining activities have led to the introduction of high levels of heavy metal (HM) concentrations in soils. This has attracted governmental and public attention due to their non-biodegradable nature and hazards posed to human health and the environment. However, total concentrations of HM are poor indicators of actual risk hazard to human health and can lead to overestimation of risk. In this study, oral bioaccessibility (the fraction available for absorption via oral ingestion), was used to refine human health risk assessment. Solid phase distribution of the HM was also investigated to characterize HM distribution and behavior in the extractive waste streams and impacted soil. The study was undertaken at an abandoned mine site from Campello Monti, in the Southern Italian Alps used for Ni exploitation from 1863 to 1940s. The results showed that total concentrations of HM were high and reached upto 7400 mg/kg for Ni due to parent material, however, only 11% was bioaccessible. Detailed analysis showed that the bioaccessible fraction (BAF) of Ni, Cu and As varied from 0.5 to 21%, 2 to 47%, and 7 to 28%, respectively. The variation can be attributed to the difference in pH, organic matter content and mineralogical composition of the samples. Results of non-specific sequential extraction showed that non-mobile forms of the elements were associated with the residual and Fe-oxides components of the matrix. The present study highlights that including bioaccessibility and solid phase distribution can refine and inform risk assessment of abandoned mine sites.