Integration of toxicological and chemical tools to assess the bioavailability of metals and energetic compounds in contaminated soils

Bioavailability is critical for understanding effects that might result from exposure of biota to contaminated soils. Soils from military range and training areas (RTAs) are contaminated principally by energetic materials (EM) and metals. Their chemical characteristics are relatively well known and toxicity assessment of soils from RTAs are in some cases available. However, bioavailability on these sites needs to be comprehensively characterized. A holistic approach to bioavailability, incorporating both chemical and earthworm toxicological indicators, was applied to soils from an anti-tank firing range at a Canadian Forces Base. Results showed that HMX and the metals Zn, Pb, Bi and Cd, though not consistently the prevailing toxicants, were the most accessible to earthworms. Some metals (notably Cu, Zn, Cr and Bi) were also accumulated in earthworm tissue but those were not necessarily expected given their bioaccessibility (i.e., the chemical availability of contaminants in the environment for the organisms) at the beginning of the exposure. The tested soils impaired earthworm reproduction and reduced adult growth. Measurement of selected sublethal parameters indicated that lysosomal integrity (determined as the neutral red retention time--NRRT) was decreased, while elevated superoxide dismutase (SOD) activity suggested that earthworms experienced oxidative stress. The correspondence between the NRRT and metal contamination pattern suggested that metals may be the main cause of lysosomal disruption in EM-contaminated soils. The approach to bioavailability appraisal adopted in this case appears to be a promising practice for site-specific assessment of contaminated land.     

Enhancing the economic potential of organic waste by co-composting using ratio modelling toward a circular economy

Journal of Material Cycles and Waste Management - Co-composting, a circular economy approach to waste management, has economic potential and environmental benefits through nutrient recycling and...     

Adapting participatory processes to fine-tune conservation approaches in multiactor decision settings

Conservation decisions are typically made in complex, dynamic, and uncertain settings, where multiple actors raise diverse and potentially conflicting claims, champion different and sometimes contradictory values, and enjoy varying degrees of freedom and power to act and influence collective decisions. Therefore, effective conservation actions require conservation scientists and practitioners to take into account the complexity of multiactor settings. We devised a framework to help conservation biologists and practitioners in this task. Institutional economic theories, which are insufficiently cited in the conservation literature, contain useful insights for conservation. Among these theories, the economies of worth can significantly contribute to conservation because it can be used to classify the types of values peoples or groups refer to when they interact during the elaboration and implementation of conservation projects. Refining this approach, we designed a framework to help conservation professionals grasp the relevant differences among settings in which decisions related to conservation actions are to be made, so that they can adapt their approaches to the features of the settings they encounter. This framework distinguishes 6 types of agreements and disagreements that can occur between actors involved in a conservation project (harmony, stricto sensu arrangement, deliberated arrangement, unilateral and reciprocal compromise, and locked-in), depending on whether they disagree on values or on their applications and on whether they can converge toward common values by working together. We identified key questions that conservationists should answer to adapt their strategy to the disagreements they encounter and identified relevant participatory processes to complete the adaptation.