Yngvar Thomassen was born in Porsgrunn, Norway, on March 25, 1947. Thomassen's academic training (cand real) was obtained in the Department of Analytical Chemistry at the University of Oslo from where he graduated in 1973. He spent one year at the Norwegian Defense Institute before taking a post research associate position at the Department of Analytical Chemistry at the University of Oslo, where he conducted research for 2 1/2 years. In 1978 he visited The University of Toronto, Department of Environmental Studies and Geology, for one year with a Royal Norwegian grant (visiting scientist).
He is currently Research Director, Department of Chemical and Biological Work Environment, National Institute of Occupational Health in Oslo where he has spent 40 years of his professional life.
He is also appointed from 2004 as a professor in environmental chemistry, Department of Plant and Environmental Sciences, at the Norwegian University of Life Sciences outside Oslo.
Thomassen is the author or co-author of 190 scientific publications, the majority focusing on atomic spectrometry and other spectrometric methods for the determination of essential and toxic elements with special emphasis on electrothermal atomic absorption spectrometry. In recent years more focus has been given to other spectrometric methods as inductively coupled plasma atomic emission and mass spectrometry. His main scientific activity during the last ten years has been in the field of environmental and occupational exposure characterisation and assessment in human health studies. His research focuses on clinical aspects of analytical chemistry and the application of atomic spectroscopy within the context of environmental and occupational health.
Thomassen has served on the Editorial Boards of The Analyst, Analytical Communication and Scandinavian Journal of Work, Environment and Health, Journal of Environmental Monitoring, Journal of Trace Elements in Medicine and Biology and Environmental Science: Processes & Impacts.
He has given over 275 presentations on various aspects of his research, of which 105 were invited lectures at major conferences and symposia. In the period 1983-91 he was a member of the Commission on Toxicology, International Union of Pure and Applied Chemistry (titular) member from 1986, where he initiated the development of human body fluids as quality assurance materials for the measurement of minor, trace and ultra-trace elements and organic metabolites. From 2011-2014 he served as a titular member in the Analytical Chemistry Division.
Thomassen has organised a number of national, nordic and international conferences on topics dealing with analytical chemistry, atomic spectroscopy and environmental and biological issues. His present research focuses on clinical aspects of analytical chemistry and the application of atomic spectroscopy within the context of environmental and occupational health.