Life cycle assessment of battery electric vehicles: Implications of future electricity mix and different battery end-of-life management

The environmental performance of battery electric vehicles (BEVs) is influenced by their battery size and charging electricity source. Therefore, assessing their environmental performance should consider changes in the electricity sector and refurbishment of their batteries. This study conducts a scenario-based Life Cycle Assessment (LCA) of three different scenarios combining four key parameters: future changes in the charging electricity mix, battery efficiency fade, battery refurbishment, and recycling for their collective importance on the life-cycle environmental performance of a BEV. The system boundary covers all the life-cycle stages of the BEV and includes battery refurbishment, except for its second use stage. The refurbished battery was modelled considering refurbished components and a 50% cell conversation rate for the second life of 5 years. The results found a 9.4% reduction in climate impacts when future changes (i.e., increase in the share of renewable energy) in the charging electricity are considered. Recycling reduced the BEV climate impacts by approximately 8.3%, and a reduction smaller than 1% was observed for battery refurbishment. However, the battery efficiency fade increases the BEV energy consumption, which results in a 7.4 to 8.1% rise in use-stage climate impacts. Therefore, it is vital to include battery efficiency fade and changes to the electricity sector when estimating the use-stage impacts of BEVs; without this, LCA results could be unreliable. The sensitivity analysis showed the possibility of a higher reduction in the BEV climate impacts for longer second lifespans (>5 years) and higher cell conversation rates (>50%). BEV and battery production are the most critical stages for all the other impact categories assessed, specifically contributing more than 90% to mineral resource scarcity. However, recycling and battery refurbishment can reduce the burden of the different impact categories considered. Therefore, manufacturers should design BEV battery packs while considering recycling and refurbishment.

Temporalis, a generic method and tool for dynamic Life Cycle Assessment

The limitations of the static nature of Life Cycle Assessment (LCA) are well known. To overcome the loss of temporal information due to the aggregation of flows in the Life Cycle Inventory (LCI), several dynamic LCA methodologies have been proposed. In this paper we present a new generic and operational methodology for dynamic LCA that allows for the introduction of temporal information in both in the inventory and the Life Cycle Impact Assessment (LCIA) phases. The method makes use of graph traversal and convolution to calculate the temporally differentiated inventory, and makes it possible to use several types of dynamic impact assessment. We describe our method and apply it to a cradle-to-grave dynamic LCA of a glued laminated timber (glulam) product. We also test the sensitivity of the global warming results to temporal explicit LCI data. There is a considerable difference in outcome between the static and dynamic approaches. We have implemented our framework in the free and open source software Temporalis that is fully operational and can be used with existing LCA databases.

EFO-LCI: A New Life Cycle Inventory Database of Forestry Operations in Europe

Life cycle assessment (LCA) has become a common methodology to analyze environmental impacts of forestry systems. Although LCA has been widely applied to forestry since the 90s, the LCAs are still often based on generic Life Cycle Inventory (LCI). With the purpose of improving LCA practices in the forestry sector, we developed a European Life Cycle Inventory of Forestry Operations (EFO-LCI) and analyzed the available information to check if within the European forestry sector national differences really exist. We classified the European forests on the basis of "Forest Units" (combinations of tree species and silvicultural practices). For each Forest Unit, we constructed the LCI of their forest management practices on the basis of a questionnaire filled out by national silvicultural experts. We analyzed the data reported to evaluate how they vary over Europe and how they affect LCA results and made freely available the inventory data collected for future use. The study shows important variability in rotation length, type of regeneration, amount and assortments of wood products harvested, and machinery used due to the differences in management practices. The existing variability on these activities sensibly affect LCA results of forestry practices and raw wood production. Although it is practically unfeasible to collect site-specific data for all the LCAs involving forest-based products, the use of less generic LCI data of forestry practice is desirable to improve the reliability of the studies. With the release of EFO-LCI we made a step toward the construction of regionalized LCI for the European forestry sector.

Levels of advanced glycosylation end-products (AGE) in sera of pregnant diabetic women: comparison between type 1, type 2 and gestational diabetes mellitus

The chronic hyperglycemia can lead to an increase of the advanced glycosylation end-products (AGE) levels on proteins and macromolecules. Abnormal levels of AGE in several tissues has been associated with the pathogenesis of late diabetic complications. In diabetic pregnant women, high AGE levels might influence the delicate maternal-fetal balance and therefore alter the pregnancy outcome. In this preliminary study, we have measured the AGE in sera of 44 diabetic women in two trimester. Sixteen sera from non diabetic pregnant women have been used as controls. The AGE have been analyzed by means of an ELISA method with an antiserum anti-RNAse-AGE, produced in the Laboratory of Clinical Biochemistry of the Istituto Superiore di Sanità. Diabetic patients type 1 and type 2, in good metabolic control, showed normal AGE levels at both trimester. Patients with gestational diabetes showed significantly high serum AGE levels (p < 0.05). A more extended study will give better insight on the association between AGE levels and a physiopathology of diabetic pregnancy.

Glucose transporters (GLUT 1, GLUT 3) mRNA in human placenta of diabetic and non-diabetic pregnancies

Glucose transporters (GLUT) catalyse the transport of glucose in many human tissues, including the placenta. On the other hand glucose concentrations can affect both glucose transport activity and level of GLUT mRNA and protein. Up to now very few studies, concerning GLUT in the placenta appeared and studies in vivo in human diabetic pregnancy are lacking. Therefore we investigated placental GLUT 1 and GLUT 3 mRNA in 10 diabetic (5 IDDM, 2 NIDDM, 3 GDM) and 9 non-diabetic women. GLUT 1 mRNA was found significantly correlated with maternal age (> 30 vs < 30 years: p < 0.025), with placental weight (> 575 vs < 575 g: p < 0.05), while GLUT 3 mRNA decreased significantly in late gestation of diabetic women (38-40 vs < 38 weeks: p < 0.025). In addition GLUT 3 was significantly lower in the diabetic than in non-diabetic women in late gestation. These preliminary results deserve to better elucidate feto-maternal carbohydrate metabolism at the placental level in normal as well as diabetic pregnancy.

Autoimmune markers of diabetes in diabetic pregnancy

Gestational diabetes mellitus (GDM) has been described in 1-3% of pregnancies and increases the risk (up to 60-70%) to subsequently developing an overt diabetes (generally of type 2 non insulin-dependent diabetes mellitus (NIDDM)). Several humoral autoimmune phenomena have been described in GDM: islet cell antibodies (ICA) have been found and it was shown that ICA+ patients tend to have a worse glucose tolerance. Recently, autoantibodies against glutamic acid decarboxylase (GAD), were detected in type 1 diabetic sera before or at the onset of the disease; these markers, as well as ICA and insulin antibodies, seem to have a predictive value for the onset of the disease. Aim of our study was to investigate the presence of GAD65 in 83 GDM, 79 NIDDM and 64 pregnant normal women in late gestation. GAD Ab positivity was found (0.035 index as limit) only in GDM and NIDDM (3.6% in GDM, 3.8% in NIDDM, and nothing in control women). These results indicate that GAD positivity in GDM overlaps that of NIDDM, suggesting that the two diabetic populations have the same predisposition to develop a type 1 diabetes mellitus, and likely they share the same disease. Further studies need to clarify whether this prevalence of GAD positivity may unmask type 1 diabetes in both GDM and NIDDM diabetic women.

Glucose transporter (Glut1, Glut3) mRNA in human placenta of diabetic and non-diabetic pregnancies

Transport of glucose into the cell is catalyzed by glucose transporters (Glut). Glut1 and Glut3 are expressed at various levels in many human tissues, including the placenta. It has been reported that ambient glucose can affect both glucose transport activity and expression of the Glut genes, and protein. To date, very few studies concerning Glut in the placenta have been published, and studies in vivo in human diabetic pregnancy are lacking. We therefore investigated placental Glut1 and Glut3 mRNA by Northern blot analysis in ten diabetic (five insulin dependent diabetes mellitus (IDDM), two non-insulin dependent diabetes mellitus (NIDDM) and three gestational diabetes mellitus (GDM)) and nine non-diabetic women. The quantitative results of specific mRNA/beta-actin ratios were expressed as arbitrary units. The results were evaluated according to metabolic and clinical findings. Glut1 and Glut3 mRNA values in diabetic and non-diabetic pregnant women were similar. The metabolic environment seems to affect the Glut3 mRNA levels in IDDM pregnant women but not the control women. In addition, Glut3 mRNA decreased in late pregnancy in the diabetic but not in the control women. Moreover, Glut1 mRNA levels were correlated with maternal age in the diabetic as well as in the control women (significantly). Finally, an inverse correlation was found between Glut1 mRNA levels and placental weight (in both diabetic and non-diabetic women). These results, although preliminary, shed some light on the function of these glucose transporters in normal as well as in diabetic pregnancies and prompt us to carry out a further investigation to better elucidate fetomaternal metabolic correlation at the placental level.

Amniotic fluid insulin and C peptide levels in diabetic and nondiabetic women during early pregnancy

Thanks to the widespread use of amniocentesis, glucose, insulin, and C peptide have often been measured in amniotic fluid (AF) during late gestation, but little is known about their concentrations during early pregnancy. To better understand early fetal beta-cell function under normal conditions and in the presence of maternal diabetes, we measured glucose, insulin, and C peptide in the AF collected during weeks 15-22 in 77 healthy and 9 diabetic women undergoing amniocentesis for clinical indications and compared the results with those obtained during late pregnancy (weeks 34-36). The AF C peptide concentration was higher in diabetic women (102 +/- 53 vs. 38 +/- 2 pmol/L), in the women with a family history of diabetes (41 +/- 6 vs. 35 +/- 2 pmol/L), after the 19th week of gestation (46 +/- 5 vs. 35 +/- 2 pmol/L; in the presence of lower glucose concentrations), and in the presence of maternal plasma glucose levels greater than 5.56 mmol/L (42 +/- 3.5 vs. 34 +/- 2 pmol/L). The comparison between early and late gestation showed decreasing glucose and increasing C peptide concentrations in both healthy and diabetic women (in the latter, C peptide values were always 3 times higher), whereas the insulin concentration was increased in late gestation only in diabetic women. The AF C peptide/insulin molar ratio increased throughout pregnancy in both healthy (from 0.97 +/- 0.06 to 4.3 +/- 1.2) and diabetic (from 2.9 +/- 1.1 to 13.2 +/- 1.6) women. These parallel changes suggest that the fetal clearance and/or degradation of insulin and C peptide may greatly change during both normal and diabetic gestation.