Dr. Apostoaei has more than 27 years of experience in various aspects of radiological and risk assessment.  He participated in the update of the Radioepidemiological Tables for the National Cancer Institute (NCI) and is one of the authors of the Interactive Radio-Epidemiological Program (IREP). IREP is currently used to estimate the probability of radiogenic cancer causation for nuclear workers.  Dr. Apostoaei participated in the design and development of a radiation risk calculator for NCI that estimates lifetime risk of cancer. The Radiation Risk Assessment Tool (RadRAT) is an online calculator [https://irep.nci.nih.gov/radrat] for estimating the lifetime risk of cancer incidence for members of the U.S. population and of other selected countries 

from exposure to ionizing radiation. The calculator uses organ-, age- and sex-specific dose estimates and reports cancer-specific and total lifetime risk along with 90% uncertainty ranges. This calculator has a wide range of applicability and has been used in various risk assessments, including studies of effects of exposure to radiation from X-ray computer tomography (CT) procedures. Dr. Apostoaei was also involved in the development of NCI's thyroid dose and risk calculator for exposure to I-131 in fallout from nuclear weapons detonated at the Nevada Test Site.  


In support of epidemiologic studies performed by the National Institute of Occupational Safety and Health (NIOSH), Dr. Apostoaei has been developing computational tools (e.g., InDEP computer code) for estimation of radiation doses from intakes of plutonium and uranium by analysis of bioassay data.

Also for NIOSH, he participated in a review of scientific information necessary to determine possible values of dose and dose rate effectiveness factors (DDREF) for use in assessing risk from chronic exposures to radiation.  Dr. Apostoaei is providing support to the National Aeronautics and Space Administration (NASA) for estimation of health risks due to exposures to space radiation.  He is currently serving the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) as an expert consultant on evaluations of health risks and their uncertainties after exposure to low-LET radiation. As a member of the NCRP (National Council on Radiation Protection and Measurements) Scientific Committee 6-3, Dr. Apostoaei was a coauthor of the NCRP Report No. 164 on uncertainties in internal dosimetry.


Dr. Apostoaei has participated in numerous dose and risk assessment studies including (a) model validation exercises related to reconstruction of doses to people from Czech Republic and Finland exposed to Cs-137 from the Chernobyl accident, (b) reconstruction of doses and estimation of risk of cancer for individuals exposed to historic releases of I-131 from the Oak Ridge Reservation, (c) estimation of radiation doses and risk of cancer from exposure to various radionuclides released into the Columbia River from Hanford Nuclear Facilities and into the Clinch River from the Oak Ridge National Laboratory, (d) reconstruction of doses for members of the public living near to the Idaho National Engineering Laboratory (INEL), (e) estimation of risk to members of public from nuclear weapons fallout in the Marshall Islands, and (f) for the NCRP, technical reviews of radiation dose and risk assessments for the Fukushima Daiichi Nuclear Power Plant damaged after the 2011 tsunami. Dr. Apostoaei has numerous years of experience in using analytical and Monte-Carlo methods for propagation and analysis of uncertainties in estimates of doses and risks.


E-mail Dr. Apostoaei at: iulian@orrisk.com

A. Iulian Apostoaei, Ph.D.

Senior Scientist