Best practices for predictions of radionuclide activity concentrations and total absorbed dose rates to freshwater organisms exposed to uranium mining/milling.

This is the final version. Available from Elsevier via the DOI in this record.Predictions of radionuclide dose rates to freshwater organisms can be used to evaluate the radiological environmental impacts of releases from uranium mining and milling projects. These predictions help inform decisions on the implementation of mitigation measures. The objective of this study was to identify how dose rate modelling could be improved to reduce uncertainty in predictions to non-human biota. For this purpose, we modelled the activity concentrations of 210Pb, 210Po, 226Ra, 230Th, and 238U downstream of uranium mines and mills in northern Saskatchewan, Canada, together with associated weighted absorbed dose rates for a freshwater food chain using measured activity concentrations in water and sediments. Differences in predictions of radionuclide activity concentrations occurred mainly from the different default partition coefficient and concentration ratio values from one model to another and including all or only some 238U decay daughters in the dose rate assessments. Consequently, we recommend a standardized best-practice approach to calculate weighted absorbed dose rates to freshwater biota whether a facility is at the planning, operating or decommissioned stage. At the initial planning stage, the best-practice approach recommend using conservative site-specific baseline activity concentrations in water, sediments and organisms and predict conservative incremental activity concentrations in these media by selecting concentration ratios based on species similarity and similar water quality conditions to reduce the uncertainty in dose rate calculations. At the operating and decommissioned stages, the best-practice approach recommends relying on measured activity concentrations in water, sediment, fish tissue and whole-body of small organisms to further reduce uncertainty in dose rate estimates. This approach would allow for more realistic but still conservative dose assessments when evaluating impacts from uranium mining projects and making decision on adequate controls of releases

A Review of Increased Enoxaparin Dosing for Venous Thromboembolism Prophylaxis in General Trauma Patients

Objective: To review the evidence regarding increased enoxaparin dosing for venous thromboembolism (VTE) prophylaxis in the general trauma patient population. Data Sources: A search of MEDLINE databases (1946 to October 2016) was conducted using the search terms enoxaparin, thromboembolism prophylaxis, venous thromboembolism, trauma, anti-factor Xa, and weight-based dosing. Additional references were identified from a review of literature citations. Study Selection and Data Extraction: Search results were limited to English-language studies conducted in humans. Trials that included onlyobese patients or nontrauma patients were excluded. Data Synthesis: A total of 7 trials (958 patients) explored the use of increased dosing of enoxaparin for VTE prophylaxis in trauma patients. Patients were divided by enoxaparin dosing strategies: standard dosing of 30 mg twice daily (BID; n = 509), higher initial dosing regimen (n = 216), or dosing based on anti-FXa level adjustments (n = 233). The majority of the 42 total VTE events (64.3%) occurred in the standard dosing regimen. Within each group, VTE was reported in 5.3% of patients in the standard dosing group, 3.2% in the higher initial dosing group, and 4% in the anti-FXa adjustment group. Initial subtherapeutic anti-FXa levels occurred in 33% to 92% of standard dose patients and 9% to 39% of higher initial dose patients. The average weight-based dose required to achieve a therapeutic level ranged between 0.43 and 0.54 mg/kg/dose BID. The overall rate of bleeding was low, with 3 incidents (0.37%) reported. Conclusion: Standard-dose enoxaparin prophylaxis may not be optimal for the general trauma patient population. Weight-based enoxaparin dosing (0.5 mg/kg/dose BID) is an option in trauma patients considered to be at a lower risk of bleeding complications

Radioecological assessments of the Iodine working group of IAEA's EMRAS programme: Presentation of input data and analysis of results of the prague scenario

In 2003 IAEA launched the EMRAS Programme aiming at evaluating the predictive power of radiological models. The programme continued work of previous international radioecological modelling programmes and comprised several working groups focusing on different aspects of environmental modelling. The Iodine Working Group reassessed the impact of the release of 131I during the Chernobyl accident with the aim of comparing model predictions with environmental data and inter-comparing the model predictions. Measurement data and detailed geographic and demographic descriptions were available for three regions: Plavsk, Warsaw and Prague. As for the Prague Scenario, milk supply regions of three big dairies were chosen for the model validation. Apart from geographic, demographic and agricultural descriptions (e.g. gathering regions of the dairies, feeding regime), the modellers were provided with information on the weather conditions and measurement data of iodine contamination. The most important peculiarities of Prague Scenario were keeping milk cattle in sheds and a special feeding regime during May 1986. The modellers were asked to assess the 131I content in the thyroid of the local population and the resulting dose. The assessments were compared with measurement data. The results of these model calculations and their comparison with experimental data are presented