Life cycle assessment of Australian automotive door skins

Background, aim, and scope  Policy initiatives, such as the EU End of Life Vehicle (ELV) Directive for only 5% landfilling by 2015, are increasing the pressure for higher material recyclability rates. This is stimulating research into material alternatives and end-of-life strategies for automotive components. This study presents a Life Cycle Assessment (LCA) on an Australian automotive component, namely an exterior door skin. The functional unit for this study is one door skin set (4 exterior skins). The material alternatives are steel, which is currently used by Australian manufacturers, aluminium and glass-fiber reinforced polypropylene composite. Only the inputs and outputs relative to the door skin production, use and end-of-life phases were considered within the system boundary. Landfill, energy recovery and mechanical recycling were the end-of-life phases considered. The aim of the study is to highlight the most environmentally attractive material and end-of-life option. Methods  The LCA was performed according to the ISO 14040 standard series. All information considered in this study (use of fossil and non fossil based energy resources, water, chemicals etc.) were taken up in in-depth data. The data for the production, use and end-of-life phases of the door skin set was based upon softwares such as SimaPro and GEMIS which helped in the development of the inventory for the different end-of-life scenarios. In other cases, the inventory was developed using derivations obtained from published journals. Some data was obtained from GM-Holden and the Co-operative research Centre for Advanced Automotive Technology (AutoCRC), in Australia. In cases where data from the Australian economy was unavailable, such as the data relating to energy recovery methods, a generic data set based on European recycling companies was employed. The characterization factors used for normalization of data were taken from (Saling et. al. Int J Life Cycle Assess 7(4):203–218 2002) which detailed the method of carrying out an LCA. Results  The production phase results in maximum raw material consumption for all materials, and it is higher for metals than for the composite. Energy consumption is greatest in the use phase, with maximum consumption for steel. Aluminium consumes most energy in the production phase. Global Warming Potential (GWP) also follows a trend similar to that of energy consumption. Photo Oxidants Creation Potential (POCP) is the highest for the landfill scenario for the composite, followed by steel and aluminium. Acidification Potential (AP) is the highest for all the end-of-life scenarios of the composite. Ozone Depletion Potential (ODP) is the highest for the metals. The net water emissions are also higher for composite in comparison to metals despite high pollution in the production phases of metallic door skins. Solid wastes are higher for the metallic door skins. Discussion  The composite door skin has the lowest energy consumption in the production phase, due to the low energy requirements during the manufacturing of E-glass and its fusion with polypropylene to form sheet molding compounds. In general, the air emissions during the use phase are strongly dependent on the mass of the skins, with higher emissions for the metals than for the composite. Material recovery through recycling is the highest in metals due to efficient separation techniques, while mechanical recycling is the most efficient for the composite. The heavy steel skins produce the maximum solid wastes primarily due to higher fuel consumption. Water pollution reduction benefit is highest in case of metals, again due to the high efficiency of magnetic separation technique in the case of steel and eddy current separation technique in the case of aluminium. Material recovery in these metals reduces the amount of water needed to produce a new door skin set (water employed mainly in the ingot casting stage). Moreover, the use of heavy metals, inorganic salts and other chemicals is minimized by efficient material recovery. Conclusions  The use of the studied type of steel for the door skins is a poor environmental option in every impact category. Aluminium and composite materials should be considered to develop a more sustainable and energy efficient automobile. In particular, this LCA study shows that glass-fiber composite skins with mechanical recycling or energy recovery method could be environmentally desirable, compared to aluminium and steel skins. However, the current limit on the efficiency of recycling is the prime barrier to increasing the sustainability of composite skins. Recommendations and perspectives  The study is successful in developing a detailed LCA for the three different types of door skin materials and their respective recycling or end-of-life scenarios. The results obtained could be used for future work on an eco-efficiency portfolio for the entire car. However, there is a need for a detailed assessment of toxicity and risk potentials arising from each of the four different types of door skin sets. This will require greater communication between academia and the automotive industry to improve the quality of the LCA data. Sensitivity analysis needs to be performed such as the assessment of the impact of varying substitution factors on the life cycle of a door skin. Incorporation of door skin sets made of new biomaterials need to be accounted for as another functional unit in future LCA studies. Discussion contributions to this article from the readership would the highly welcome. The authors     

Influence of assumptions about selection and recycling efficiencies on the LCA of integrated waste management systems

Background, aim, and scope  Life cycle assessment (LCA) applied to alternative waste management strategies is becoming a commonly utilised tool for decision makers. This LCA study analyses together material and energy recovery within integrated municipal solid waste (MSW) management systems, i.e. the recovery of materials separated with the source-separated collection of MSW and the energy recovery from the residual waste. The final aim is to assess the energetic and environmental performance of the entire MSW management system and, in particular, to evaluate the influence of different assumptions about recycling on the LCA results. Materials and methods  The analysis uses the method of LCA and, thus, takes into account that any recycling activity influences the environment not only by consuming resources and releasing emissions and waste streams but also by replacing conventional products from primary production. Different assumptions about the selection efficiencies of the collected materials and about the quantity of virgin material substituted by the reprocessed material were made. Moreover, the analysis considers that the energy recovered from the residual waste displaces the same quantity of energy produced in conventional power plants and boilers fuelled with fossil fuels. Results  The analysis shows, in the expanded model of the material and energy recovering chain, that the environmental gains are higher than the environmental impacts. However, when we reduce the selection efficiencies by 15%, the impact indicators worsen by a percentage included between 10% and 26%. This phenomenon is even more evident when we consider a substitution ratio of 1:<1 for paper and plastic: The worsening is around 15–20% for all the impact indicators except for the global warming for which the worsening is up to 45%. Discussion  Hypotheses about the selection efficiencies of the source-separated collected materials and about the substitution ratio have a great influence on the LCA results. Consequently, policy makers have to be aware of the fact that the impacts of an integrated MSW management system are highly dependent on the assumptions made in the modelling of the material recovery, as well as in the modelling of the energy recovery. Conclusions  LCA allows to evaluate the impacts of integrated systems and how these impacts change when the assumptions made during the modelling of the different single parts of the system are modified. Due to the significant impacts that hypotheses about material recovery have in the results, they should be expressed in a very transparent way in the report of LCA studies, together with the assumptions made about energy recovery. Recommendations and perspectives  The results suggest that the hypotheses about the value of the substitution ratio are very important, and the case of wood should therefore be better analysed and a substitution ratio of 1:<1 should be used, as for paper and plastic. It seems that the assumptions made about which material is replaced by the recycled one are very important too, and in this sense, more research is needed about what the recycled plastic may effectively substitute, in particular the polyolefin mix.     

A greenhouse gas indicator for bioenergy: some theoretical issues with practical implications

Background, aim, and scope  The expectations with respect to biomass as a resource for sustainable energy are sky-high. Many industrialized countries have adopted ambitious policy targets and have introduced financial measures to stimulate the production or use of bioenergy. Meanwhile, the side-effects and associated risks have been pointed out as well. To be able to make a well-informed decision, the Dutch government has expressed the intention to include sustainability criteria into relevant policy instruments. Main features  Among other criteria, it has been proposed to calculate a so-called life-cycle-based greenhouse gas (GHG) indicator, which expresses the reduction of GHG emissions of a bio-based fuel chain in comparison with a fossil-based fuel chain. Life-cycle-based biofuel studies persistently have problems with the handling of biogenic carbon balances and with the treatment of coproducts and recycling. In life-cycle assessments (LCAs) of agricultural products, a distinction between “negative” and “positive” emissions may be relevant. In particular, carbon dioxide, as a naturally occurring compound or an anthropogenic emission, takes part in the so-called geochemical carbon cycle. The most appropriate way to treat carbon cycles is to view them as genuine cycles and, thus, at the systems level, subtract the fixation of CO₂ during tree growth from the CO₂ emitted during waste treatment of discarded wood and to quantify the CH₄ emitted. In solving the multifunctionality problem, two steps may be distinguished. The first concerns the modeling of the product system studied in the inventory analysis. In this step, system boundaries are set, processes are described, and process flows are quantified. Multifunctionality problems can be identified and the model of the product system is drafted. The second step concerns solving the remaining multifunctionality problems. For this step, various ways of solving the multifunctionality problem have been proposed and applied, on the basis of mass, energy, economic value, avoided burdens, etc. As the GHG indicator may constitute the basis for granting subsidies to stimulate the use of bioenergy, for example, and as the method for the GHG indicator provides no guidelines on the handling of biogenic CO₂ and guidelines for solving multifunctionality problems such as with coproducts and recycling that leave room for various choices, this study analyzed whether the current GHG indicator provides results that are a robust basis for granting such subsidies. Results  For the robustness check, a hypothetical case study on wood residue-based electricity was set up in order to illustrate what the effects of different solutions and choices for the two steps mentioned may be. The case dealt with the production of wood pellets (residues of the wood industry) that are cofired in a coal-fired power plant. The functional unit is 1 kWh of electricity. Three possibilities for the places of the multifunctional process, two possibilities for whether or not to include biogenic CO₂, and four possibilities for the allocation method were distinguished and calculated. Varying the options for these three choices in this way appears to have a huge effect on the GHG indicator, while no clear pattern seems to emerge. Discussion  The results found for this hypothetical case indicate that there are several methodological choices that have not sufficiently been fixed by the presently available standards and guidelines for LCA and GHG assessment of bioenergy systems. In particular, we have focused on issues related to biogenic CO₂ and allocation, two issues that play a prominent role in the assessment of bioenergy systems. Moreover, we have demonstrated with a small hypothetical case study that these are not only issues that might theoretically show up, but that they play a decisive role in practice. Conclusions  The present (Dutch) GHG indicator lacks robustness, which will raise problems for providing a sound basis for granting subsidies. This situation can, however, be improved by reducing the freedom of choices for the handling of biogenic CO₂ and allocation to an absolute minimum. Recommendations and perspectives  Even then, however, differences could appear due to different definitions, data sources, and method interpretations. It thus appears that two kinds of guidance are needed: (1) the LCA methodology itself should be expanded with guidelines for those issues that follow from science, logic, or consensus; (2) in the policy regulation that demands LCA to be the basis of the decision, additional guidelines should be specified that perhaps do not (yet) have the status of being scientifically proven or generally agreed upon, but that serve as a set of temporary extra guidelines.

Assessment of physiological conditions in E. coli fermentations by epifluorescent microscopy and image analysis

The development of monitoring methods for assessing the physiological state of microorganisms during recombinant fermentation processes has been encouraged by the need to evaluate the influence of processing conditions in recombinant protein production. In this work, a technique based on microscopy and image analysis was developed that allows the simultaneous quantification of parameters associated with viability and fluorescent protein production in recombinant Escherichia coli fermentations. Images obtained from light microscopy with phase contrast are used to assess the total number of cells in a given sample and, from epifluorescence microscopy, both protein producing and injured cells are evaluated using two different fluorochromes: propidium iodide and enhanced yellow fluorescent protein. This technique revealed the existence of different cell populations in the recombinant E. coli fermentation broth that were evaluated along four batch fermentations, complementing information obtained with standard techniques to study the effects of the temperature and induction time in recombinant protein production processes. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009     

The deterrent effect of bird song in territory defense

Using the responses of territory owners to playback to inferthe territorial function of acoustic signals is common practice.However, difficulties with interpreting the results of suchexperiments have obscured our understanding of territorial signalling.For instance, a stronger response to playback is often interpretedas more aggressive, but there is no consensus as to whetherthis should be in response to the least or most threateningsimulated intruder. Rather than following a gradual increaseor decrease, the relationship between signal intensity and responsestrength may instead describe a peaked curve. We manipulatedbanded wren (Thryophilus pleurostictus) songs to simulate low-,median-, and high-performance singers and used these songs asstimuli in playback experiments. Banded wrens were less likelyto approach the high-performance stimulus compared with thelow- and median-performance stimuli. However, the birds thatdid approach the high-performance stimulus sang more than thosethat approached the low-performance stimulus. In addition, birdswere more likely to match the songs when exposed to the median-and high-performance stimuli compared with the low-performancestimuli, and song matching predicted approach behavior. Theseresults are in accordance with theoretical models of aggressiveencounters in which low-performance opponents are challengedwithout further assessment. Median- and high-performance opponents,however, may require further assessment, and the latter maybe perceived as too intimidating for approach.     

Encapsulation of the metacercariae of two species of trematodes in the skin and musculature of the stone cockscomb <Emphasis Type="Italic">Alectrias alectrolophus</Emphasis> (Pallas, 1814)

The structure of the coating surrounding the metacercaria of Cryptocotyle lingua in the skin and the metacercaria of Liliatrema skrjabini in the muscles of the stone cockscomb was studied. Metacercariae of these trematodes were surrounded by a cyst adjacent to the helminth and by a capsule. In both species, the cyst consisted of electron- dense homogeneous material, which was probably synthesized by the parasite. The capsules were formed from host tissues; in C. lingua, they mostly consisted of ordered layers of collagen fibers and in L. skrjabini they were formed from fibroblasts and, presumably, phagocytes. The differences in capsule structure of the studied metacercariae may be related to the physiological features of surrounding tissues or to the taxonomic attribution of the trematodes.     

Human Health Risk Assessment for Environmental Exposure to Metals in the Catalan Stretch of the Ebro River,Spain

The aim of this study was to investigate the environmental impact and the human health risks associated with metals exposure in the Catalan stretch of the Ebro River, Spain. The concentrations of the following elements were determined in soils and tap water: As, Cd, Cr, Cu, Hg, Mn, Ni, and Pb. Carcinogenic and non-carcinogenic risks were separately assessed for adults and children. Relatively low metal concentrations in tap water were found. It indicates that water intake is not a relevant source of metals for human health impact in the area under evaluation. In turn, the levels of metals in soils were similar or less than those found in a number of recent worldwide surveys. The presence of industrial facilities located upstream the Ebro River, including a chloralkali plant, should not mean additional non-carcinogenic risks for the population living in the area. The results of the current study allow us to establish that the concentrations of most carcinogenic elements (with the exception of As) should not mean potential health risks for the local population. However, because of the relatively high levels of geological origin found for As, a continued monitoring of these elements would be desirable.     

Risk Assessment for Dermal Exposure of Organochlorine Pesticides for Local Fishermen in the Rangsit Agricultural Area,Central Thailand

Organochlorine pesticides (OCPs) used in agriculture and for public health purposes were banned in Thailand over the past decade; however, their persistent residues have been found in several agricultural areas of the country. This may result in adverse effects to human populations. This study investigated the concentration of organochlorine pesticides residues (OCPRs) in surface water and evaluated the potential cancer risk associated with dermal contact of the local fisherman fishing in the Khlong 7 canal, Rangsit agricultural area, central Thailand. Water samples were extracted using liquid-liquid extraction (LLE) and then analyzed by gas chromatography with microelectron capture detector (μ -ECD). The results show that low concentrations of OCPRs were detected in parts per billion (ppb or ng/ml) levels, that is, ∑ Endosulfan (α -, β -, and -sulfate) 0.082 ng/ml > DDT and derivatives 0.019 ng/ml > ∑ HCH (α -, γ -, β -, and δ -HCH) 0.014 ng/ml > aldrin and dieldrin 0.007 ng/ml > heptachlor and heptachlor epoxide 0.0068 ng/ml > endrin and endrin aldehyde 0.005 ng/ml > methoxychlor 0.001 ng/ml, respectively. Using the worst-case scenario defined as the reasonable maximum exposure (RME) to assess the potential cancer risk, five OCPs (dieldrin, 4,4′ -DDT, β -HCH, heptachlor, and heptachlor epoxide) may pose a risk of concern on a lifetime human carcinogenesis greater than one in a million.     

Phthalates Biomarker Identification and Exposure Estimates in a Population of Pregnant Women

Phthalates are known reproductive and developmental toxicants in experimental animals. However, in humans, there are few data on the exposure of pregnant women that can be used to assess the potential developmental exposure experienced by the fetus. We measured several phthalate metabolites in maternal urine, maternal serum, and cord serum samples collected at the time of delivery from 150 pregnant women from central New Jersey. The urinary concentrations of most metabolites were comparable to or less than among the U.S. general population, except for mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), three metabolites of di(2-ethylhexyl) phthalate (DEHP). The median urinary concentrations of MEHHP (109 μ g/l) and MEOHP (95.1 μ g/l) were more than 5 times their population-based concentrations, whereas the median urinary concentration of MEHP was more than 20 times higher. High concentration of MEHP may indicate a recent exposure to the parent chemical DEHP in the hospital shortly before the collection of the samples. Calculation of daily intakes using the urinary biomarker data reveals that none of the pregnant women tested had integrated exposures to DEHP greater than the Agency for Toxic Substances and Disease Registry's minimal risk levels (MRLs chronic 60, intermediate 100 μ g/kg/day). No abnormal birth outcomes (e.g., birth weight, Apgar Score, and gestational age) were noted in those newborns whose mothers had relatively greater exposure to DEHP during the perinatal period than others in this study. Significantly greater concentrations and detection frequencies in maternal urine than in maternal serum and cord serum suggest that the urinary concentrations of the phthalate metabolites may be more reliable biomarkers of exposure than their concentrations in other biological specimens.