Life cycle impact assessment of terrestrial acidification: modeling spatially explicit soil sensitivity at the global scale

This paper presents a novel life cycle impact assessment (LCIA) approach to derive spatially explicit soil sensitivity indicators for terrestrial acidification. This global approach is compatible with a subsequent damage assessment, making it possible to consistently link the developed midpoint indicators with a later endpoint assessment along the cause-effect chain-a prerequisite in LCIA. Four different soil chemical indicators were preselected to evaluate sensitivity factors (SFs) for regional receiving environments at the global scale, namely the base cations to aluminum ratio, aluminum to calcium ratio, pH, and aluminum concentration. These chemical indicators were assessed using the PROFILE geochemical steady-state soil model and a global data set of regional soil parameters developed specifically for this study. Results showed that the most sensitive regions (i.e., where SF is maximized) are in Canada, northern Europe, the Amazon, central Africa, and East and Southeast Asia. However, the approach is not bereft of uncertainty. Indeed, a Monte Carlo analysis showed that input parameter variability may induce SF variations of up to over 6 orders of magnitude for certain chemical indicators. These findings improve current practices and enable the development of regional characterization models to assess regional life cycle inventories in a global economy.     

Papillary cystic neoplasm of the pancreas: radiological findings

We report a series of 10 papillary cystic neoplasms of the pancreas evaluated in our institution. The lesions are analyzed in retrospect to define the existence of eventual specific imaging patterns as well as to point out the existing problems of differential diagnosis versus other pancreatic tumors.     

Sonoelectrochemical (20 kHz) production of platinum nanoparticles from aqueous solutions

The present work describes the production of platinum nanoparticles from aqueous chloroplatinic solutions in the presence of low-frequency high-power ultrasound (20 kHz) on titanium alloy electrodes. The production of this new type of Pt nanoparticles was performed galvanostatically at (298 ± 1) K using a newly designed experimental set-up and ‘sonoelectrode’ producing ultrasonic pulses triggered and followed immediately by short applied current pulses. From galvanostatic studies, it was shown that Pt mean grain size ranging from 11 to 15 nm was produced. Morphological and structural studies of the produced nanoparticles were performed by TEM, SEM, XRD and SAED and showed that Pt nanoaggregates were predominantly formed, with no redissolution of the nanoaggregates. Globular clusters had a mean size ranging between 100 and 200 nm which in turn aggregated and built complex structures.     

Iron–chromium alloy nanoparticles produced by pulsed sonoelectrochemistry: Synthesis and characterization

This study describes synthesis of Fe–Cr alloy nanoparticles by using a method which couples electrodeposition of metals with the employment of high power ultrasound. The production of alloyed nanoparticles was performed using a 20 kHz titanium alloy horn ultrasound generator, a “sonoelectrode” generating short current pulses (t_ON) triggered and followed immediately by ultrasonic pulses (t_US). A rest time (t_r) restores the initial conditions close to the sonoelectrode. The final product is a suspension of nanoparticles with high purity and high surface/volume ratio, which could be controlled by varying process parameters like time management and current density.     

Environmental impacts of remediation of a trichloroethene-contaminated site: life cycle assessment of remediation alternatives

The environmental impacts of remediation of a chloroethene-contaminated site were evaluated using life cycle assessment (LCA). The compared remediation options are (i) in situ bioremediation by enhanced reductive dechlorination (ERD), (ii) in situ thermal desorption (ISTD), and (iii) excavation of the contaminated soil followed by off-site treatment and disposal. The results showed that choosing the ERD option will reduce the life-cycle impacts of remediation remarkably compared to choosing either ISTD or excavation, which are more energy-demanding. In addition to the secondary impacts of remediation, this study includes assessment of local toxic impacts (the primary impact) related to the on-site contaminant leaching to groundwater and subsequent human exposure via drinking water. The primary human toxic impacts were high for ERD due to the formation and leaching of chlorinated degradation products, especially vinyl chloride during remediation. However, the secondary human toxic impacts of ISTD and excavation are likely to be even higher, particularly due to upstream impacts from steel production. The newly launched model, USEtox, was applied for characterization of primary and secondary toxic impacts and combined with a site-dependent fate model of the leaching of chlorinated ethenes from the fractured clay till site.     

Development of normalization factors for Canada and the United States and comparison with European factors

In Life Cycle Assessment (LCA), normalization calculates the magnitude of an impact (midpoint or endpoint) relative to the total effect of a given reference.The goal of this work is to calculate normalization factors for Canada and the US and to compare them with existing European normalization factors. The differences between geographical areas were highlighted by identifying and comparing the main contributors to a given impact category in Canada, the US and Europe. This comparison verified that the main contributors in Europe and in the US are also present in the Canadian inventory. It also showed that normalized profiles are highly dependent on the selected reference due to differences in the industrial and economic activities. To meet practitioners' needs, Canadian normalization factors have been calculated using the characterization factors from LUCAS (Canadian), IMPACT 2002+ (European), and TRACI (US) respectively. The main sources of uncertainty related to Canadian NFs are data gaps (pesticides, metals) and aggregated data (metals, VOC), but the uncertainty related to CFs generally remains unknown. A final discussion is proposed based on the comparison of resource extraction and resource consumption and raises the question of the legitimacy of defining a country by its geographical borders.     

Assessing regional intake fractions in North America

This paper develops the IMPACT North America model, a spatially resolved multimedia, multi-pathway, fate, exposure and effect model that includes indoor and urban compartments. IMPACT North America allows geographic differentiation of population exposure of toxic emissions for comparative risk assessment and life cycle impact assessment within U.S. and Canada. It looks at air, water, soil, sediment and vegetation media, and divides North America into several hundred zones. It is nested within a single world box to account for emissions leaving North America. It is a multi-scale model, covering three different spatial scales — indoor, urban and regional — in all zones in North America. Model results are evaluated against monitored emissions and concentrations of benzo(a)pyrene, 2,3,7,8-TCDD and mercury. Most of the chemical concentrations predicted by the model fall within two orders of magnitude of the monitored data. The model shows that urban intake fractions are one order of magnitude higher than rural intake fractions. The model application and importance is demonstrated by a case study on spatially-distributed emissions over the life cycle of diesel fuel. Depending on population densities and agricultural intensities, intake fractions can vary by eight orders of magnitudes, and even limited indoor emissions can lead to intakes comparable to those from outdoor emissions. To accurately assess these variations in intake fraction, we require the essential three original features described in the present paper: i) inclusion of the continental model within a world box for persistent pollutants, ii) addition of an urban box for short- and medium-lived substances (for grid size larger than 100 km), and iii) assess indoor emissions. This model can therefore be used to screen chemicals and assess regionalized intake fractions within North America for population-based human exposure assessment, life cycle impact assessment, and comparative risk assessment. The model can be downloaded at http://www.impactmodeling.org.