Statistical matching for conservation science

The awareness of the need for robust impact evaluations in conservation is growing and statistical matching techniques are increasingly being used to assess the impacts of conservation interventions. Used appropriately matching approaches are powerful tools, but they also pose potential pitfalls. We outlined important considerations and best practice when using matching in conservation science. We identified 3 steps in a matching analysis. First, develop a clear theory of change to inform selection of treatment and controls and that accounts for real-world complexities and potential spillover effects. Second, select the appropriate covariates and matching approach. Third, assess the quality of the matching by carrying out a series of checks. The second and third steps can be repeated and should be finalized before outcomes are explored. Future conservation impact evaluations could be improved by increased planning of evaluations alongside the intervention, better integration of qualitative methods, considering spillover effects at larger spatial scales, and more publication of preanalysis plans. Implementing these improvements will require more serious engagement of conservation scientists, practitioners, and funders to mainstream robust impact evaluations into conservation. We hope this article will improve the quality of evaluations and help direct future research to continue to improve the approaches on offer.     

Swedish recovered wood waste: linking regulation and contamination

In Sweden, large amounts of wood waste are generated annually from construction and demolition activities, but also from other discarded products such as packaging and furniture. A large share of this waste is today recovered and used for heat production. However, previous research has found that recovered wood waste (RWW) contains hazardous substances, which has significant implications for the environmental performance of recycling. Improved sorting is often suggested as a proper strategy to decrease such implications. In this study, we aim to analyse the impacts of waste regulation on the contamination of RWW. The occurrence of industrial preservative-treated wood, which contains several hazardous substances, was used as an indicator for contamination. First the management of RWW during 1995-2004 was studied through interviews with involved actors. We then determined the occurrence of industrial preservative-treated wood in RWW for that time period for each supplier (actor). From the results, it can be concluded that a substantially less contaminated RWW today relies on extensive source separation. The good news is that some actors, despite several obstacles for such upstream efforts, have already today proved capable of achieving relatively efficient separation. In most cases, however, the existing waste regulation has not succeeded in establishing strong enough incentives for less contaminated waste in general, nor for extensive source separation in particular. One important factor for this outcome is that the current market forces encourage involved actors to practice weak quality requirements and to rely on end-of-pipe solutions, rather than put pressure for improvements on upstream actors. Another important reason is that there is a lack of communication and oversight of existing waste regulations. Without such steering mechanisms, the inherent pressure from regulations becomes neutralized.     

Developing a monitoring method facilitating continual improvements in the sorting of waste at recycling centres

Beneficial use of waste relies on efficient systems for collection and separation. In Sweden, a bring system involving recycling centres for collection of bulky, electr(on)ic and hazardous waste has been introduced. A significant share of this waste is incorrectly sorted, causing downstream environmental implications. At present, however, there is a lack of affordable and accurate monitoring methods for providing the recycling centres with the necessary facts for improving the sorting of waste. The aim of this study was therefore to evaluate the usability of a simplified and potentially more suitable waste monitoring method for recycling centres. This method is based on standardised observations where the occurrence of incorrect sorting is monitored by taking digital pictures of the waste which then are analysed according to certain guidelines. The results show that the developed monitoring method could offer a resource-efficient and useful tool for proactive quality work at recycling centres, involving continuous efforts in developing and evaluating measures for improved sorting of waste. More research is however needed in order to determine to what extent the obtained results from the monitoring method are reliable.     

Overview of state approaches to vapor intrusion

A large number of states have issued guidance addressing the vapor intrusion pathway making it difficult to keep up with various policies and requirements. We have compiled and reviewed guidance from 35 states, half of which have issued documents within the last three years. A comparison of policies among states shows reasonable consistency in some areas—for example, 20 of 23 states that provide an exclusion distance for subsurface sources of chlorinated volatile organic compounds (VOCs) use a distance of 100 feet. However, more commonly, the policy decisions vary widely. Among states, indoor air screening concentrations for the same VOC vary by more than 2,000 times and subsurface screening concentrations vary by more than 2,000,000 times. These wide discrepancies suggest a need for communication and consensus building in order to increase consistency in the management of the vapor intrusion pathway. © 2012 Wiley Periodicals, Inc.     

A Regional Cadmium Inventory: interpretation and management

Local authorities in Sweden are responsible for the management of sewage treatment and municipal solid waste. Due to this, they handle large flows and stocks of materials and substances that may be harmful for the environment. However, knowledge about these flows is sometimes deficient. In addition, the capacity to influence the composition of these flows is mainly beyond the jurisdiction of the local authorities. Flow-oriented studies, such as substance flow analysis (SFA), have proven to be a useful tool in order to understand and quantify these flows. Furthermore, SFA is sometimes claimed to be beneficial to the process of decision making, since it generates comprehensive overviews of the substance in focus. However, quantification of stocks and flows of a certain substance does not necessarily provide sufficient information for environmental management on the local level. Hence, for SFA to further contribute to the environmental management process, there is also a need for development in the interpretation of the results. The main objective of this paper is to contribute to the discussion about (1) how to interpret the results from SFA and (2) how the results from an SFA can be used in environmental management by local authorities. A tentative framework for interpretation is discussed in the paper, focusing on five aspects: total material quantities, exposure to humans and the environment, resource economy, function and capacity to influence the substance flows. Furthermore, the paper discusses the suggested framework applied to results of a regional cadmium inventory.     

Cadmium in sewage sludge in a Swedish region: sources and reduction opportunities

To create a more sustainable future, one of the Swedish government’s aims is to close the eco-cycles between urban consumption areas and arable land. Increasing the use of sewage sludge from municipal wastewater treatment plants (MWTPs) is one method of achieving this goal. However, the use of sewage sludge is often prohibited due to its high concentrations of cadmium. As a consequence, large amounts of sewage sludge are deposited each year in landfills. This disposal has become more expensive for local authorities due to a new deposit tax introduced in the year 2000. Based on a survey of cadmium sources to MWTPs in a Swedish region this paper focuses on opportunities local authorities in Sweden have to influence the occurrence of cadmium in the sewage sludge. The results from the study show that cadmium in sewage sludge originates from diffuse sources, which are hard for local authorities to influence by direct means. This is most obvious for sources of cadmium in wastewater from households, which causes about one-third of the inflow of cadmium to MWTPs. Thus, the local authorities’ possibilities are, in general, still restricted to downstream actions (such as disconnecting identified industrial sources and reconstructing the sewage system to further separate collection of wastewater and storm water). Local authorities could also implement changes in the process at the MWTP or an extended treatment of the sewage sludge generated. Nonetheless, these possible measures do not provide a sustainable solution to the cadmium issue since the origins of the sources remain. Hence, long-term strategies — outside of the scope of local authorities — need to focus on a general decrease of cadmium in society. However, increased knowledge about the distribution among different sources of cadmium to MWTPs may encourage local authorities to establish priorities for measures that will improve the quality of the sewage sludge.     

Gender and international crisis response: do we have the data,and does it matter?

For more than a decade the humanitarian community has been mandated to mainstream gender in its response to crises. One element of this mandate is a repeated call for sex-disaggregated data to help guide the response. This study examines available analyses, assessments and academic literature to gain insights into whether sex-disaggregated data are generated, accessible and utilised, and appraised what can be learned from existing data. It finds that there is a gap between policy and practice. Evaluations of humanitarian responses rarely refer to data by sex, and there seems to be little accountability to do so. Yet existing data yield important information, pointing at practical, locally-specific measures to reduce the vulnerability of both males and females. This complements population-level studies noting the tendency for higher female mortality. The study discusses some possible obstacles for the generation of data and hopes to spur debate on how to overcome them.