Research Experience

2005- Research Professor and Director, U.S. Transuranium & Uranium Registries, Washington State University, Richland, WA.

2004-05 Research Professor and Associate Director, U.S. Transuranium & Uranium Registries, Washington State University, Richland, WA.

2004- Faculty Affiliate, Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO.

2004- Faculty Affiliate, Department of Physics, Health Physics Program, Idaho State University, Pocatello, ID.

2001-04 Adjunct Professor, Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University, Pullman, WA.

1995- Internal dosimetry consultant and President of consulting and internal dosimetry software-development company.

1994-95 Associate Research Professor, United States Transuranium and Uranium Registries, College of Pharmacy, Washington State University, Tri-Cities Branch Campus, Richland, WA.
* Research on internal dosimetry, radionuclide biokinetics, and risk modeling in conjunction with the U.S. Transuranium and Uranium Registries.
* Provided independent scientific advice and consultancy services in internal dosimetry, exposure and risk assessment.

1991-94 Laboratory Fellow, Occupational Health Protection Section and Health Protection Department, Pacific Northwest Laboratory, Richland, WA.
* Led research projects, carried out research and consultancy work related to internal dosimetry, and mentored scientific colleagues in the Occupational Health Protection Section of the Life Sciences Center.

1989-91 Technical Group Leader, Exposure, Biokinetic and Dosimetric Modeling, Health Physics Department, Pacific Northwest Laboratory, Richland, WA.
* Formed and led Technical Group of four research scientists, two postdoctoral research fellows, and one technical specialist.
* Carried out research for DOE/OHER to review biological behavior of radon daughters and develop state-of-the-art models to evaluate doses to human and animal tissues.
* Carried out dosimetric modeling study for industrial client to evaluate effects of operating air cleaning device on lung doses from radon daughters in home environments.
* Led DOE/OHER research project to model microdosimetry of target cells in human lung from exposure to radon daughters, and also microdosimetry of cells exposed in culture.
* Led DOE/OHER research project to develop instruments and methods to improve characterization and control of the exposure of experimental animals to radon progeny (Aerosol Technology Development).
* Collaborated with overseas and PNL colleagues to complete development of deposition, clearance and dosimetry models, and prepared two Chapters for 1991 draft ICRP Task Group Report.
* Prepared expert evidence on doses to respiratory tract and body organs of subjects exposed in their home to 239Pu in household dust for U.K. industrial client, and appeared on behalf of client in the High Court, London, for cross-examination.
* Collaborated with PNL colleagues to study feasibility of measuring surface activity of long-lived 210Po in personal artifacts as index of past exposure and bronchial dose in case-control epidemiological studies of radon and lung cancer.
* Carried out modeling study of relative doses to sensitive cells in bronchial epithelium from human exposures to radon daughters in mines and in homes, and contributed two chapters to National Academy of Science's Committee Report on this subject.

1988-89 Staff Scientist, Biology and Chemistry Department, Pacific Northwest Laboratory, Richland, WA.
* Collaborated with overseas colleagues to develop draft lung deposition, clearance and dosimetry models for ICRP Task Group on Human Respiratory Tract Models for Radiological Protection.
* Carried out modeling study of doses to regions of the respiratory tract and body organs from exposure to airborne ceramic microspheres containing 210Po for industrial client.
* Led exploratory research on fluid mechanical, particle transport and computer graphics modeling of respiratory airways.
* Led the DOE/OHER research project in "Aerosol Technology Development."

1986-88 Group Leader, Airborne Radionuclides, Radiological Measurement Department, NRPB, Chilton, Oxfordshire, UK.
* Development of conversion factor between exposure to radon in homes and risk underlying NRPB's recommended standard for limiting public exposure in UK.
* Assessment of results from NRPB's systematic national survey of population exposure to radon, and likely incidence of high exposures in particular geological and administrative regions of UK.
* Led development of procedures to identify individual homes and areas of UK at risk, operating system to conduct large scale surveys of annual exposure to radon, and administrative system to respond to public, local authority and government department's demands.
* Led programs to screen schools, mines and other workplaces for radon: to find those requiring radiological supervision according to UK regulations, and to develop remedies.
* Led experimental studies of penetration of sub-micron aerosols and unattached radon daughters through hollow cast of human nose, and of radon daughter aerosol characteristics in mines and homes.

1982-86 Group Leader, Aerosol Monitoring and Dosimetry, Physics Department, NRPB, Chilton, Oxfordshire, UK.
* Development of NRPB's facilities to serve as European Reference Laboratory for radon and daughter metrology.
* Development of method and equipment to measure radon daughter concentrations in methane atmospheres (coal mines).
* Development of field instrument to measure the activity-size distribution of radon daughter aerosols.
* Study of statistical uncertainty in estimating intakes of plutonium from low levels of activity collected by personal air samplers.
* Development of a general model of lung deposition, clearance mechanisms and dose to human respiratory tissues.

1977-82 Group Leader, Aerosols and Biophysics, Biology Department, NRPB, Chilton, Oxfordshire, UK.
* Experimental study and modeling kinetics of clearance of Pb ions and insoluble particles in nasal epithelium of the rat.
* Study of clearance and metabolism of industrial actinide dusts administered to rodents by inhalation.
* Study of clearance of insoluble particles from alveolar lung in human volunteers.
* Development of model to calculate aerosol deposition in human respiratory tract and bronchial dose from exposure to radon and thoron daughters.

1974-77 Section Leader, Biology Department, NRPB, Harwell, Oxfordshire, UK.
* Study of kinetics of clearance of Pb ions from bronchial epithelium to blood, in rabbit.
* Development of experimental facility to expose rodents by inhalation to toxic actinide dusts.
* Development of external counting techniques to measure clearance of Pu, Am and U oxides from lungs of individual rodents.
* Development of methods for sampling and characterizing actinide dusts from workplaces.

1971-74 Research Scientist, National Radiological Protection Board (NRPB), Harwell, Oxfordshire, UK.
* Development of field methods to measure radon daughter equilibrium and unattached fraction of potential ?-energy.
* Study of size distribution of long-lived airborne ?-activity in workplaces.
* Study of deposition of radon daughter aerosols in the bronchial tree using ventilated, excised lungs of pig.

1970-71 Research Scientist, Medical Research Council, Radiological Protection Service, Surrey, UK.
* Study radon daughter concentrations in underground mines.

1966-70 Medical Research Council Fellow, Royal Free Hospital School of Medicine, London, UK.
* Experimental dosimetry of cells at bone surfaces for 239Pu in rat skeleton.
* Sub-cellular localization of plutonium by electron-microscopy and autoradiography using 241Pu.
* Development of thin silicon surface barrier energy-loss detector to measure LET spectra for neutrons in tissue equivalent absorbers.

1964-65 Scientist, British Insulated Callendars Cables Research Laboratory, London, UK.
* Development of electrical and mechanical instrumentation.