The use of stable isotopes ((13)C/(12)C and (15)N/(14)N) to trace exposure to oil sands processed material in the Alberta oil sands region.

Various oil sands reclamation strategies incorporate oil sands processed material (OSPM) such as mature fine tailings (MFT), engineered tailings (consolidated tailings, CT), and tailings pond water (TPW) into reclamation components that need to develop into viable aquatic ecosystems. The OSPM will contain elevated salinity and organics such as naphthenic acids (NA) and polycyclic aromatic compounds (PAC) that can be chronically toxic to aquatic organisms depending upon levels and age. Due to the complexity of the chemical mixtures, analysis of these compounds in exposed organisms can be challenging. In this study, the stable carbon and nitrogen isotope signatures of selected invertebrates from various types of oil sands reclamation sites were analyzed to determine whether stable isotopes can be used to trace the exposure of aquatic organisms to organic constituents of OSPM. In a series of experimental reclamation ponds of similar age and size, there were trends of (13)C depletion and (15)N enrichment for benthic invertebrates along a gradient of increased levels of MFT and/or TPW. A survey of 16 sites revealed high delta(15)N values for invertebrates in aquatic systems containing MFT and CT (gypsum-treated mixes of MFT and tailings sand), which was attributed to the presence of NH(4)(+), a process by-product in OSPM. Findings of this study indicate a potential for the use of stable nitrogen isotopes to define exposure of biota to OSPM during environmental effects monitoring programs both in surface waters and in cases where groundwater seepage containing oil sands processed water enters surface receiving environments in the region.

Solution-focused therapy. Counseling model for busy family physicians.

OBJECTIVE: To provide family doctors in busy office practices with a model for counseling compatible with patient-centred medicine, including the techniques, strategies, and questions necessary for implementation. QUALITY OF EVIDENCE: The MEDLINE database was searched from 1984 to 1999 using the terms psychotherapy in family practice, brief therapy in family practice, solution-focused therapy, and brief psychotherapy. A total of 170 relevant articles were identified; 75 abstracts were retrieved and a similar number of articles read. Additional resources included seminal books on solution-focused therapy (SFT), bibliographies of salient articles, participation in workshops on SFT, and observation of SFT counseling sessions taped by leaders in the field. MAIN MESSAGE: Solution-focused therapy's concentration on collaborative identification and amplification of patient strengths is the foundation upon which solutions to an array of problems are built. Solution-focused therapy offers simplicity, practicality, and relative ease of application. From the perspective of a new learner, MECSTAT provides a framework that facilitates development of skills. CONCLUSION: Solution-focused therapy recognizes that, even in the bleakest of circumstances, an emphasis on individual strength is empowering. In recognizing patients as experts in self-care, family physicians support and accentuate patient-driven change, and in so doing, are freed from the hopelessness and burnout that can accompany misplaced feelings of responsibility.