Comparison of Three Different LCIA Methods: EDIP97, CML2001 and Eco-indicator 99

Goal, Scope and Background

A number of impact assessment methodologies are available to the LCA practitioner. They differ, and often there is not one obvious choice among them. The question therefore naturally arises: ‘Does it make any difference to my conclusions which method I choose?’ To investigate this issue, a comparison is performed of three frequently applied life cycle impact assessment methods.

Methods

The three life cycle impact assessment methods EDIP97 [1], CML2001 [2] and Eco-indicator 99 [3] are compared on their performance through application to the same life cycle inventory from a study of a water-based UV-lacquer. EDIP97 and CML2001 are both midpoint approaches and hence quite similar in their scope and structure, and this allows a comparison during both characterisation and normalisation. The third impact assessment method Eco-indicator 99 is an endpoint method and different in scope and structure from the other two. A detailed comparison can not be done but a comparative analysis of the main contributors to the Eco-indicator 99 results and the weighted and aggregated EDIP97 results is performed.

Results and Discussion

Following a translation into common units of the EDIP97 and CML2001 output, differences up to two orders of magnitude are found for some of the indicator results for the impact categories describing toxicity to humans and ecosystems, and there is little similarity in the patterns of major contributors among the two methods. For human toxicity the CML2001 score is dominated by contribution from metals while the EDIP97 score is caused by a solvent and nitrogen oxides. For aquatic ecotoxicity, metals are the main contributors for both methods but while it is vanadium for CML2001, it is strontium for EDIP97. After normalisation, the differences are reduced but still considerable. For the other impact categories, the two methods show only minor differences. The comparison of the main contributors to the Eco-indicator 99 results and the weighted and aggregated EDIP97 results identifies nitrogen oxides as the main contributor for both methods. It is, however, much more dominant for Eco-indicator 99 while the EDIP97 score represents important contributions from a number of different substances, and furthermore, the analysis reveals that the aggregated scores for the two methods come from different impacts. It is thus difficult to extend the findings for these two methods to other inventories.

Conclusion

For EDIP97 and CML2001, it mainly matters which method is used if the chemical impacts on human health and ecosystem health are important for the study. For the other impact categories, the differences are minor for these two methodologies. For EDIP97 and Eco-indicator 99, the patterns of most important contributors to the weighted and aggregated impact scores are rather different, and considering the known differences in the underlying framework and models, the results of the two methods may well go in opposite directions for some inventories even if the conclusion is the same for the inventory studied in this paper.

Recommendations and Oudook

Particularly for the impact categories representing toxic impacts from chemicals, the study demonstrates the need for more a detailed analysis of the causes underlying the big differences revealed between the methods.

     

Paleoenvironmental study of the Carquefou site (Massif Armoricain, France) from the end of the Sub-boreal

The town of Carquefou, some 10 km northeast of Nantes on the left bank of the river Erdre, occupies a site long associated with human activity. During road construction east of the town, ditches, enclosures and post holes characteristic of the late la Tène were discovered at the locality of “Le Clouet”, which led us to obtain core samples from a nearby peat bog. These investigations indicated the changes in vegetation since 3915±95 uncal B.P., [2828 (2459) 2074 cal B.C.]. The slopes in the surroundings of the bog have been relatively treeless since the Bronze Age, but a very open woodland vegetation composed of Tilia, Corylus and Quercus has been maintained until the present day. In the area around the bog, and Alnus wood with an undergrowth of Cyperaceae was the dominant vegetation, despite some changes probably related to human occupation since the Bronze Age. Beginning at 955±35 uncal B.P. [1004 (1036, 1144, 1146) 1181 cal A.D.], in the Middle Ages, the alders disappeared almost totally, apparently because of clearance or an increase in water level. Human presence led to intensified cultivation of different crops including Cannabis and especially Cerealia. Finally, the presence of a variety of anthropogenic indicator plants (Cichorioideae, Asteraceae, Plantago lanceolata, etc.) suggests that cattle were reared in the vicinity of the site. Received May 22, 2000 / Accepted March 29, 2001     

Thiazolyl Peptide Antibiotic Biosynthesis: A Cascade of Post-translational Modifications on Ribosomal Nascent Proteins

Antibiotics of the thiocillin, GE2270A, and thiostrepton class, which block steps in bacterial protein synthesis, contain a trithiazolyl (tetrahydro)pyridine core that provides the architectural constraints for high affinity binding to either the 50 S ribosomal subunit or elongation factor Tu. These mature antibiotic scaffolds arise from a cascade of post-translational modifications on 50–60-residue prepeptide precursors that trim away the N-terminal leader sequences (∼40 residues) while the C-terminal 14–18 residues are converted into the mature scaffold. In the producing microbes, the genes encoding the prepeptide open reading frames are flanked in biosynthetic clusters by genes encoding post-translational modification enzymes that carry out lantibiotic-type dehydrations of Ser and Thr residues to dehydroamino acid side chains, cyclodehydration and oxidation of cysteines to thiazoles, and condensation of two dehydroalanine residues en route to the (tetrahydro)pyridine core. The trithiazolyl pyridine framework thus arises from post-translational modification of the peptide backbone of three Cys and two Ser residues of the prepeptide.     

Cultivation of Heligmosomoides Polygyrus: An Immunomodulatory Nematode Parasite and its Secreted Products

Heligmosomoides polygyrus (formerly known as Nematospiroides dubius, and also referred to by some as H. bakeri) is a gastrointestinal helminth that employs multiple immunomodulatory mechanisms to establish chronic infection in mice and closely resembles prevalent human helminth infections. H. polygyrus has been studied extensively in the field of helminth-derived immune regulation and has been found to potently suppress experimental models of allergy and autoimmunity (both with active infection and isolated secreted products). The protocol described in this paper outlines management of the H. polygyrus life cycle for consistent production of L3 larvae, recovery of adult parasites, and collection of their excretory-secretory products (HES).     

Rice Os9BGlu31 Is a Transglucosidase with the Capacity to Equilibrate Phenylpropanoid,Flavonoid, and Phytohormone Glycoconjugates

Glycosylation is an important mechanism of controlling the reactivities and bioactivities of plant secondary metabolites and phytohormones. Rice (Oryza sativa) Os9BGlu31 is a glycoside hydrolase family GH1 transglycosidase that acts to transfer glucose between phenolic acids, phytohormones, and flavonoids. The highest activity was observed with the donors feruloyl-glucose, 4-coumaroyl-glucose, and sinapoyl-glucose, which are known to serve as donors in acyl and glucosyl transfer reactions in the vacuole, where Os9BGlu31 is localized. The free acids of these compounds also served as the best acceptors, suggesting that Os9BGlu31 may equilibrate the levels of phenolic acids and carboxylated phytohormones and their glucoconjugates. The Os9BGlu31 gene is most highly expressed in senescing flag leaf and developing seed and is induced in rice seedlings in response to drought stress and treatment with phytohormones, including abscisic acid, ethephon, methyljasmonate, 2,4-dichlorophenoxyacetic acid, and kinetin. Although site-directed mutagenesis of Os9BGlu31 indicated a function for the putative catalytic acid/base (Glu¹⁶⁹), catalytic nucleophile residues (Glu³⁸⁷), and His³⁸⁶, the wild type enzyme displays an unusual lack of inhibition by mechanism-based inhibitors of GH1 β-glucosidases that utilize a double displacement retaining mechanism.     

HMGB1 Protein Does Not Mediate the Inflammatory Response in Spontaneous Spinal Cord Regeneration: A HINT FOR CNS REGENERATION*

Uncontrolled, excessive inflammation contributes to the secondary tissue damage of traumatic spinal cord, and HMGB1 is highlighted for initiation of a vicious self-propagating inflammatory circle by release from necrotic cells or immune cells. Several regenerative-competent vertebrates have evolved to circumvent the second damages during the spontaneous spinal cord regeneration with an unknown HMGB1 regulatory mechanism. By genomic surveys, we have revealed that two paralogs of HMGB1 are broadly retained from fish in the phylogeny. However, their spatial-temporal expression and effects, as shown in lowest amniote gecko, were tightly controlled in order that limited inflammation was produced in spontaneous regeneration. Two paralogs from gecko HMGB1 (gHMGB1) yielded distinct injury and infectious responses, with gHMGB1b significantly up-regulated in the injured cord. The intracellular gHMGB1b induced less release of inflammatory cytokines than gHMGB1a in macrophages, and the effects could be shifted by exchanging one amino acid in the inflammatory domain. Both intracellular proteins were able to mediate neuronal programmed apoptosis, which has been indicated to produce negligible inflammatory responses. In vivo studies demonstrated that the extracellular proteins could not trigger a cascade of the inflammatory cytokines in the injured spinal cord. Signal transduction analysis found that gHMGB1 proteins could not bind with cell surface receptors TLR2 and TLR4 to activate inflammatory signaling pathway. However, they were able to interact with the receptor for advanced glycation end products to potentiate oligodendrocyte migration by activation of both NFκB and Rac1/Cdc42 signaling. Our results reveal that HMGB1 does not mediate the inflammatory response in spontaneous spinal cord regeneration, but it promotes CNS regeneration.     

Solution structure of the soluble receptor for advanced glycation end products (sRAGE)

The receptor for advanced glycation end products (RAGE) is a multiligand cell surface receptor involved in various human diseases, as it binds to numerous molecules and proteins that modulate the activity of other proteins. Elucidating the three-dimensional structure of this receptor is therefore most important for understanding its function during activation and cellular signaling. The major alternative splice product of RAGE comprises its extracellular region that occurs as a soluble protein (sRAGE). Although the structures of sRAGE domains were available, their assembly into the functional full-length protein remained unknown. We observed that the protein has concentration-dependent oligomerization behavior, and this is also mediated by the presence of Ca(2+) ions. Moreover, using synchrotron small angle x-ray scattering, the solution structure of human sRAGE was determined in the monomeric and dimeric forms. The model for the monomer displays a J-like shape, whereas the dimer is formed through the association of the two N-terminal domains and has an elongated structure. These results provide insights into the assembly of the RAGE homodimer, which is essential for signal transduction, and the sRAGE:RAGE heterodimer that leads to blockage of the receptor signaling, paving the way for the design of therapeutic strategies for a large number of different pathologies.     

Lifestyle interventions for non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multi-factorial disease and the most common of chronic liver diseases worldwide. The four clinical-pathological entities which are usually followed by NAFLD course include non-alcoholic steatosis, non-alcoholic steatohepatitis, advanced fibrosis/cirrhosis, and hepatocellular carcinoma. The cornerstones of NAFLD management and treatment, however, are healthy lifestyles such as dietary modifications, regular physical activity, and gradual weight loss. At present, no drugs or pharmacological agents have been approved for long-term treatment of NAFLD. Therefore, lifestyle modification is considered the main clinical recommendation and an initial step for the management of NAFLD.     

Sorgoleone,a sorghum root exudate: Algicidal activity and acute toxicity to the ricefish Oryzias latipes

The discovery of natural and natural-based compounds has resulted in its application as an alternative to synthetic algicides to control harmful algae in aquatic systems. Of the many natural-product-based algicides, sorgoleone, a natural plant product from Sorghum bicolor root exudates has been investigated for its controlling effect on different algal species and its acute fish toxicity. Growth of the blue green algal species Microcystis aeruginosa Kützing was completely inhibited by the crude methanol extract of sorghum root at 20 μg mL⁻¹. The most noticeable inhibition was observed in the bioassay of n-hexane soluble extract, where 98% growth inhibition occurred in M. aeruginosa at the concentration of 1.25 μg mL⁻¹. Sorgoleone very effectively controlled blue green algae inhibiting 97% of M. aeruginosa at 0.5 μg mL⁻¹ and 99% of Anabaena affinis Lemmermann at 4 μg mL⁻¹. In contrast, inhibition of the green algae species Chlorella vulgaris Beijerinck and Scenedensmus spp. at 16 μg mL⁻¹ sorgoleone was 87 and 68%, respectively. There were no mortalities or adverse effects observed in any of the fish exposed to water control, solvent control, and a nominal concentration of 1 μg mL⁻¹ during the test period. The no observed effect concentration (NOEC) value was 1.5 μg mL⁻¹ for the tested fish (O. latipes). Sorgoleone can be considered as an effective and an ecologically and environmentally sustainable approach to controlling harmful algae.