LCA approaches for quantifying the environmental impact of plastics in the marine environment

Transcription

1 LCA approaches for quantifying the environmental impact of plastics in the marine environment Summary Graduation Project Report by Otto Faasse from Avans University of Applied Science, Breda IVAM UvA BV 25 July 2014 Amsterdam

2 Introduction Plastics are useful, versatile and cheap materials. In addition, they often have good recycling possibilities. In practice, the material cycle of plastics is not a closed loop, as is shown in figure 1. The environmental impact of plastics can be studied using Life Cycle Assessment (LCA). Several phases in the life cycle of plastics have been studied before in detail, and their environmental impact can be quantified. For other phases in the life cycle, this quantification is much more problematic. Littering is one of the more difficult life cycle phases to model using LCA. In this study, we made a start gathering literature data on which types of plastics end up in litter, which fraction ends up as plastic marine litter (), and what the environmental effects are. In a case study, a first attempt was made to show the full impact of a plastic bag, including the littering phase. - CO 2 emission - energy recovery composting incineration landfill export, improper treatment raw materials product use additives -weight saving -extended product life -convenience (spilled pellets) - resource depletion - energy use CO 2 - energy saving - exposure to additives - toxic emissions littering, dumping loss during use: wear & tear Plastic Marine Litter: -physical effects -leaching of chemicals -ingestion, starvation -economic damage Figure 1 The life cycle of plastics. Calculation of Characterization Factors Approaches to calculate characterization factors for were based on the following types of effects: Physical impact by ingestion Physical impact by entanglement Chemical impact by additives Economic impact For physical effects by ingestion, we took a detailed look at studies on the presence of plastic in stomachs of North Sea fulmars. We analyzed which correlations are described in literature on the presence of plastics in their stomachs and observed health effects. Another approach was to use the Ecological Quality Objective which the OSPAR commission has devised for the North East Atlantic. OSPAR has set a limit of maximal 10% of the fulmars having more

3 Shadow price in than 0.1 gram of plastic in their stomachs. By comparing this limit to other Quality Objectives, e.g. concentration limits for PCBs, DDT and HCB, it may be possible to obtain a quantitative measure for the effects of. Literature study was also done on quantitative data on rates of entanglement of animals, and their possible health effects on the population/ecosystem level. For some often used plastic additives, ecotoxicity characterization factors are available in LCA-methods. Using standard emission scenarios used in risk assessments, the environmental emissions and effects of a model additive were quantified (the plasticizer diisooctylphthalate). Plastic bags cause economic impact due to damage to ships or water works, reduced revenues from tourism and the costs of cleaning up and managing the waste. Data on economic impact are more concrete than the numbers on environmental impact. Impact Assessment From all approaches for deriving a quantitative measure of the impact of, the economic impact approach proved to be most practical. By combining the known economic costs of plastic marine litter with an existing LCA method based on 'shadow costs', the contribution of litter to the total environmental impact over the life cycle of a plastic bag could be quantified. Average European data were used on production and End-of-Life scenarios. Results are shown in figure 2. In this calculation, contributes around 5% to the total environmental impact of the plastic bag Damage to marine environment Ecotoxicity, terrestric (TETP) Ecotoxicity, marine sediment (MSETP) Ecotoxcity, marine water (MAETP) Ecotoxicity, freshwater sediment (FSETP) Ecotoxicity, fresh water (FAETP) Human toxicity (HT) Eutrophication (EP) Acidification (AP) Photochemical oxidation (POCP) Ozone layer depletion (ODP) Global warming (GWP) Figure 2 Environmental impact over the whole lifecycle of 1000 kg plastic bags, using a shadow costs method.

4 Single score LCA points As a sensitity analysis, a characterisation factor for in the ReCiPe LCA method was estimated, by linking the shadow price of to ReCiPe characterisation factors of chemical emissions with a similar shadow price. The result of this exercise is shown in figure 3. Due to differences in the weighting systems of both LCA methods, the results show several differences. The contribution of however seems to be similar. Further work is necessary to analyze the validity of these outcomes. 160, 140, 120, 100, 80, 60, 40, 20, 0, -20, -40, Damage to marine ecosystem Fossil depletion Metal depletion Natural land transformation Urban land occupation Agricultural land occupation Ionising radiation Freshwater ecotoxicity Terrestrial ecotoxicity Particulate matter formation Photochemical oxidant formation Human toxicity Freshwater eutrophication Terrestrial acidification Climate change Ecosystems Climate change Human Health Figure 3 Environmental impact of the total life cycle of 1000 kg of plastic bag calculated with the extended ReCiPe method. Conclusions Using the LCA approach as a tool to quantify the impact of marine litter is not impossible. However finding usable data on impacts and quantities of marine litter remains a challenge. Systematic scientific research on marine litter is relatively new and still relatively scarce. This makes quantifying the impact of plastic very hard. Plastic litter has many potential types of environmental impact, and stays in the environment for a long time. At first as litter items and later as smaller particles (micro/nano plastics). Especially this last group is surrounded by a lot of uncertainties. A number of impact mechanisms should be combined in the LCA characterization factors. Measuring the amount of plastic litter ending up as marine litter has not been standardized yet. Data on emissions is therefore based partly on assumptions. The shadow price of is surrounded by uncertainty as well. The actual shadow price could be higher as more clean-up or prevention measures are applied. The costs of collecting from open sea could result in a significantly higher shadow price. The LCA methodology delivers (apparently) clear outcomes. Every characterization factor gives a certain impact in the graph. A sensitivity analyses can provide a little bit of a spread between the answers but

5 cannot really visualize the uncertainties that are inside a characterization factor. A potential added value for the LCA method would be to have the ability to add an impact category of worry or uncertainty. This can be seen in the result as a bar that visualizes the uncertainties around an impact. For now LCA is not yet fully equipped for analysing the impact of as there are too many uncertainties around the potential impacts of this elusive environmental threat.