Development of ecotoxicological terrestrial effet data in the context of life cycle impact assessment

点击翻译按钮获取中文摘要

Within life cycle assessment (LCA), life cycle impact assessment (LCIA) translates the inventory of emissions from a product's life cycle (from raw materials extraction until end of life) into an environmental profile of the product, representing its potential contributions to a wide range of environmental impacts. LCIA relies on substance-specific characterization factors (CFs) to represent the relative contribution of the substance to health and environmental impacts. In life cycle assessment, the impacts related to pollutant emissions to soil remain poorly characterized, and several challenges must still be addressed. One such challenge is biased terrestrial effect modeling using aquatic ecotoxicological data (EC50) extrapolated from default soil-water distribution coefficients (Kd) due to the lack of terrestrial ecotoxicological effect data. The extrapolation approach for some pollutants is considered so uncertain that no CFs were calculated for them. This is preoccupying since the lack of characterization factors may be interpreted as an absence of terrestrial ecotoxicological impacts in a decision-making process driven by LCA. As such, there is a need to produce new terrestrial effect data in order to provide more meaningful ecotoxicity results. This project will improve the characterization of ecotoxicological impacts by assessing new terrestrial effect data. These new data will be produced by adapting and improving a cost-effective methodology developed in our laboratory for pentachlorophenol (PCP) that has been proven to yield terrestrial biodiversity indicators that are highly representative of the studied soil bacterial communities using PCR-denaturing gradient gel electrophoresis (DGGE) technology and calculating ecological species diversity indices. The EC50 needed to calculate the CFs are obtained from these diversity indices. As soil microbial communities are indigenous organisms that are not grown in the laboratory and composed of thousands of interacting species that differ in terms of their ecological niche and metabolic potential, this methodology has the potential to help fill the many gaps in the terrestrial ecotoxicological databases. The main goal of the project is to improve the new framework to derive soil microbial biodiversity indicators and to produce new soil phyla effect data (EC50) in order to better assess the reliability of the terrestrial ecotoxicological impact category in LCIA. The specific objectives are to: 1) adapt the framework to develop new EC50 for organics other than PCP; 2) test whether the framework can derive ecotoxicity quality criteria (EQC) such as HC50EC50 and 3) test whether the framework can derive new terrestrial effect data for an inorganic (Zn). CFs will be calculated based on the new effect data, and the new CFs will be integrated and operationalized in IMPACT World+ through case studies. In the long term, the research will make it possible to better assess the characterization of the terrestrial ecotoxicological impact by providing new CFs for substances that currently have none.