Estimating soil emissions and toxicity impacts from the application of livestock manure: application to heavy metals at national scale

摘要

Aiming for a more efficient use of resources, the European Commission encourages the use of animal manure as a fertilizer providing nutrients and organic matter to improve crop productivity and soil fertility [1,2]. However livestock manure contains traces from pathogens, veterinary medicines and feed additives (e.g. antibiotics and heavy metals), which may cause damages to ecosystems and human health. To prevent large damages from happening, tools such as Environmental risk assessment (ERA) and life cycle assessment (LCA) are used to evaluate the environmental risks and impacts of the pollutant emissions resulting from manure application. Both methodologies first require an estimation of the emissions to soil as part of their respective stages of exposure assesment and life cycle inventory analysis.To provide consistent support to high level policy-makers, e.g. supporting regulations on the use of such substances in livestock production, large-scale assessments are required. To date, the total emissions of harmful substances resulting from the application of manure at country level have however been rarely quantified. We therefore developed a framework to estimate these releases to soil in a systematic way. We applied it to emissions of 8 heavy metals (HMs) in 215 countries from 2000 to 2014 and analysed the resulting environmental toxicity-related impacts based on life cycle impact assessment.