Michiel C. Zijp

Definition and Applications of a Versatile Chemical Pollution Footprint Methodology

Because of the great variety in behavior and modes of action of chemicals, impact assessment of multiple substances is complex, as is the communication of its results. Given calls for cumulative impact assessments, we developed a methodology that is aimed at expressing the expected cumulative impacts of mixtures of chemicals on aquatic ecosystems for a region and subsequently allows to present these results as a chemical pollution footprint, in short: a chemical footprint. Setting and using a boundary for chemical pollution is part of the methodology. Two case studies were executed to test and illustrate the methodology. The first case illustrates that the production and use of organic substances in Europe, judged with the European water volume, stays within the currently set policy boundaries for chemical pollution. The second case shows that the use of pesticides in Northwestern Europe, judged with the regional water volume, has exceeded the set boundaries, while showing a declining trend over time. The impact of mixtures of substances in the environment could be expressed as a chemical footprint, and the relative contribution of substances to that footprint could be evaluated. These features are a novel type of information to support risk management, by helping prioritization of management among chemicals and environmental compartments.

Beyond safe operating space: finding chemical footprinting feasible.

Feasible Leo Posthuma,*,† Anders Bjorn,‡ Michiel C. Zijp,†,∥ Morten Birkved,‡ Miriam L. Diamond, Michael Z. Hauschild,‡ Mark A. J. Huijbregts, Christian Mulder,† and Dik Van de Meent†,∥ †RIVM, Centre for Sustainability, Environment and Health, P.O. Box 1, 3720BA Bilthoven, The Netherlands ‡DTU Management Engineering, Quantitative Sustainability Assessment, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark Dept Earth Sciences, 22 Russell Street, University of Toronto, Toronto, M5S 3B1, Canada Dept Environmental Science, Institute for Water and Wetland Research, Radboud University, 6525AJ Nijmegen, The Netherlands

Chemical Footprints: Thin Boundaries Support Environmental Quality Management

Quality Management E impacts of rising global chemical emissions are neither known nor globally regulated, while impacts of single chemicals and mixtures can currently be demonstrated and assessed locally or on a landscape scale (e.g., ref 3). In response, we developed and outlined a novel vision on chemical footprinting to support communication and decisions promoting safe chemical management at all spatial scales. Further, we presented case studies showing typical steps and results obtained with the method. However, in their Letter “Footprints and Safe Operation Space: Walk the Line?”, Pfister and Raptis’ (P&R) raised concerns about our view and proposed life cycle assessment methods as an alternative solution. We reply to P&R, recommending that the footprint approach is sound and that we need multiple, not just one approach to work toward chemical safety. P&R’s concerns partly relate to the limited details in our Viewpoint. These concerns are addressed in cited case studies. For example, P&R refer to the need to address temporal aspects that were, in fact, addressed using multimedia environmental chemical modeling as one approach. We disagree with P&R that our approach legitimizes pollution: our approach helps to judge impacts and to compare safe chemical management options, observing that emissions occur and tend to grow while dilution options are not endless. While we have made progress with chemical footprinting, we acknowledge that many scientific challenges remain and we need multiple approaches. And beyond science, we must design how footprinting can serve safe global chemical governance (e.g., ref 8). We firmly believe that our viewpoint outlines a way to reach a point on the horizon where we have safe global governance of chemicals. We disagree with P&R that footprinting delivers bad decision support. They stated that “the planetary boundary [is] not a thin but a very broad line”, on which “we might appear to always be walking [...], almost independently of the level of pollution”. We advocate the opposite. Since the 1980s, scientists have provided a basis for deriving and implementing chemical boundaries for single chemicals, via species sensitivity distribution modeling and other approaches. These science-based boundaries are thin lines, while predicted impacts of single chemicals could and can be predicted only with uncertainty. Nonetheless, management actions triggered by comparing predicted or observed concentrations with these established environmental quality criteria have resulted in reduced chemical impacts. The most hazardous chemicals have been banned, and the most hazardous situations have been contained. Our footprint can similarly assist with choosing the safest management option, and can be compared to boundaries designed to be safe. Waiting for the ideal method would leave room for an unnecessary increase in hazard(s). Our viewpoint urges collaboration among many disciplines, including management sciences. Reasoning back from a (shared) point on the horizon−following the adage of “design, then ref ine”−we draw on approaches from risk assessment, ecology, life cycle assessment and other fields. We submit that chemical footprinting is one way forward to provide sound decision support from the local to the global scale to achieve chemical safety. Leo Posthuma*,† Anders Bjørn‡ Michiel C. Zijp†,∥ Morten Birkved‡ Miriam L. Diamond Michael Z. Hauschild‡ Mark A. J. Huijbregts Christian Mulder† Dik Van de Meent†,∥ †RIVM, Centre for Sustainability, Environment and Health, P.O. Box 1, 3720BA Bilthoven, The Netherlands ‡DTU Management Engineering, Quantitative Sustainability Assessment, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark Dept Earth Sciences, 22 Russell Street, University of Toronto, Toronto, M5S 3B1, Canada Dept Environmental Science, Institute for Water and Wetland Research, Radboud University, 6525AJ Nijmegen, The Netherlands

Method selection for sustainability assessments: The case of recovery of resources from waste water

Sustainability assessments provide scientific support in decision procedures towards sustainable solutions. However, in order to contribute in identifying and choosing sustainable solutions, the sustainability assessment has to fit the decision context. Two complicating factors exist. First, different stakeholders tend to have different views on what a sustainability assessment should encompass. Second, a plethora of sustainability assessment methods exist, due to the multi-dimensional characteristic of the concept. Different methods provide other representations of sustainability. Based on a literature review, we present a protocol to facilitate method selection together with stakeholders. The protocol guides the exploration of i) the decision context, ii) the different views of stakeholders and iii) the selection of pertinent assessment methods. In addition, we present an online tool for method selection. This tool identifies assessment methods that meet the specifications obtained with the protocol, and currently contains characteristics of 30 sustainability assessment methods. The utility of the protocol and the tool are tested in a case study on the recovery of resources from domestic waste water. In several iterations, a combination of methods was selected, followed by execution of the selected sustainability assessment methods. The assessment results can be used in the first phase of the decision procedure that leads to a strategic choice for sustainable resource recovery from waste water in the Netherlands.

Identification and ranking of environmental threats with ecosystem vulnerability distributions

Responses of ecosystems to human-induced stress vary in space and time, because both stressors and ecosystem vulnerabilities vary in space and time. Presently, ecosystem impact assessments mainly take into account variation in stressors, without considering variation in ecosystem vulnerability. We developed a method to address ecosystem vulnerability variation by quantifying ecosystem vulnerability distributions (EVDs) based on monitoring data of local species compositions and environmental conditions. The method incorporates spatial variation of both abiotic and biotic variables to quantify variation in responses among species and ecosystems. We show that EVDs can be derived based on a selection of locations, existing monitoring data and a selected impact boundary, and can be used in stressor identification and ranking for a region. A case study on Ohio’s freshwater ecosystems, with freshwater fish as target species group, showed that physical habitat impairment and nutrient loads ranked highest as current stressors, with species losses higher than 5% for at least 6% of the locations. EVDs complement existing approaches of stressor assessment and management, which typically account only for variability in stressors, by accounting for variation in the vulnerability of the responding ecosystems.