S C Sheppard
Affiliation: ECOMatters Inc
Country: Canada R0E 1L0
- An index of radioecology, what has been important?S C Sheppard
ECOMatters Inc, PO Box 430, Pinawa, Manitoba, Canada R0E 1L0
J Environ Radioact 68:1-10. 2003..Obviously, this is somewhat imperfect, but it does provide an index of what has been important in radioecology, and provides some quantification to recent statements about the future of radioecology...
- Verification of radionuclide transfer factors to domestic-animal food products, using indigenous elements and with emphasis on iodineS C Sheppard
ECOMatters Inc, WB Lewis Business Centre, Manitoba, Canada
J Environ Radioact 101:895-901. 2010..This suggests that for long-term assessments, it may be advisable to change the models to use CR rather than TF...
- Transfer factors to Whitetail deer: comparison of stomach-content, plant-sample and soil-sample concentrations as the denominatorS C Sheppard
ECOMatters Inc, WB Lewis Business Centre, 24 Aberdeen Avenue, Suite 105, Pinawa, Manitoba, Canada R0E 1L0 Electronic address
J Environ Radioact 126:434-7. 2013..Thus it is reasonable to estimate CR(m-soil) from CR(m-plant) and CR(plant-soil) if observed CR(m-soil) values are not available, but this introduces further uncertainty...
- Inferences about radionuclide mobility in soils based on the solid/liquid partition coefficients and soil propertiesGustav Sohlenius
Geological Survey of Sweden, Box 670, 751 28, Uppsala, Sweden
Ambio 42:414-24. 2013..For many elements, mobility increased with decreasing soil pH. The results provide a significant addition of data on radionuclide retention in soils, taking account of soil properties and processes...
- Trace elements in feed, manure, and manured soilsS C Sheppard
ECOMatters Inc, Canada
J Environ Qual 41:1846-56. 2012....
- Variation in background concentrations and specific activities of 36Cl, 129I and U/Th-series radionuclides in surface watersS C Sheppard
ECOMatters Inc, WB Lewis Business Centre, Pinawa, MB, Canada R0E 1L0
J Environ Radioact 106:27-34. 2012....
- Ecotoxicity of aged uranium in soil using plant, earthworm and microarthropod toxicity testsS C Sheppard
ECOMatters Inc, 24 Aberdeen Avenue, Pinawa, MB, R0E 1L0, Canada
Bull Environ Contam Toxicol 88:43-7. 2012..Survival of Orthonychiurus folsomi was diminished 20% (EC(20)) by ~85-130 mg U kg(-1), supporting a PNEC in the range of 100-250 mg U kg(-1) as derived previously...
- Plant/soil concentration ratios for paired field and garden crops, with emphasis on iodine and the role of soil adhesionS C Sheppard
ECOMatters Inc, 24 Aberdeen Avenue, Pinawa, Manitoba, Canada
J Environ Radioact 101:1032-7. 2010..Although, this correlation is expected, measures of correlation coefficients suitable for stochastic risk assessment are not frequently reported. The results suggest that r ≈ -0.7 would be appropriate for risk assessment...
- Measured elemental transfer factors for boreal hunter/gatherer scenarios: fish, game and berriesS C Sheppard
ECOMatters Inc, WB Lewis Business Centre, Manitoba R0E 1L0, Canada
J Environ Radioact 101:902-9. 2010....
- Risk indicator for agricultural inputs of trace elements to Canadian soilsS C Sheppard
ECOMatters Inc, 24 Aberdeen Ave, Pinawa, MB, Canada R0E 1L0
J Environ Qual 38:919-32. 2009..The geographic distribution reflects agricultural intensity. Contributions from micronutrient fertilizers are perhaps the most uncertain due to the limited data available on their use...
- Primordial radionuclides in Canadian background sites: secular equilibrium and isotopic differencesS C Sheppard
ECOMatters Inc, P O Box 430, Pinawa, MB, Canada R0E 1L0
J Environ Radioact 99:933-46. 2008..In general, the results of this study will benefit risk assessment, both in providing background concentrations, but also some indication of where isotope activity ratios can and cannot be used to estimate concentrations...
- Revision and meta-analysis of selected biosphere parameter values for chlorine, iodine, neptunium, radium, radon and uraniumS C Sheppard
ECOMatters Inc, 24 Aberdeen Avenue, P O Box 430, Pinawa, Manitoba, Canada R0E 1L0
J Environ Radioact 89:115-37. 2006....
- Parameterization of a dynamic specific activity model of 14C transfer from surface water-to-humansS C Sheppard
ECOMatters Inc, 24 Aberdeen Avenue, Box 430, Pinawa, Manitoba, Canada, R0E 1L0
J Environ Radioact 87:15-31. 2006..The model coupled with these parameter values represents several new developments for modelling 14C transfers...
- Conceptual approaches for the development of dynamic specific activity models of 14C transfer from surface water to humansS C Sheppard
ECOMatters Inc, 24 Aberdeen Avenue, Box 430, Pinawa, Manitoba, Canada R0E 1L0
J Environ Radioact 87:32-51. 2006..Selection of parameter values to represent the turnover rates as modeled is important, and is dealt with in a companion paper...
- Derivation of ecotoxicity thresholds for uraniumSteve C Sheppard
ECOMatters Inc, Box 430, Pinawa, Manitoba, Canada R0E 1L0
J Environ Radioact 79:55-83. 2005..8 mg U L(-1) water; and >100 mg CaCO3 L(-1) (hard water)--23 mg U L(-1) water; or as a function of hardness--0.26 (hardness as mg CaCO3 L(-1); mammals--0.1 mg U kg(-1) body weight d(-1)...
- Interpolation of solid/liquid partition coefficients, K(d), for iodine in soilsS C Sheppard
ECOMatters Inc, PO Box 430, Pinawa, Manitoba R0E 1L0, Canada
J Environ Radioact 70:21-7. 2003..The practical implication of this finding is that, with K(d) data for a few benchmark soils in a region, one could estimate K(d) for other soils. The potting soil did not conform, and there are several possible explanations for this...
- Who gets to be an author...fallout from a recent controversyS C Sheppard
J Environ Radioact 68:89-91. 2003
- Modeling estimates of the effect of acid rain on background radiation doseS C Sheppard
Atomic Energy of Canada Limited, Environmental Research Branch, Whiteshell Nuclear Research Establishment, Manitoba
Environ Health Perspect 78:197-205. 1988..Although health effects following such a small increase in dose have not been statistically demonstrated, any increase in dose is probably undesirable...