ONG Choon Nam is a professor in the Department of Community, Occupational and Family Medicine, National University of Singapore.  He is currently the Director for the Centre for Environmental and Occupational Health at NUS.

He has made important contributions to the understanding of environmental exposure to xenobiotics and carcinogenesis, in particular the molecular mechanisms of how carcinogen caused cellular and DNA damage and has published more than 200 papers in international peer-reviewed journals. Professor ONG is a member of the International Life Science Institute (ILSI) based in Washington, DC and he was the recipient of the Astra-Zeneca Award for 2001.

Since 1985, Professor Ong has served as a consultant to the World Health Organization on Environmental Health and was involved in twelve of its Environmental Health Criteria publications.  He has been an Associate Editor of Environmental Research, the foremost journal in the field of environmental health, since 1995.  He is also on the editorial or advisory board of several international environmental and occupational health journals.  He has been a visiting professor to Fudan University, and Sun Yet-Sen University since the 1990s and recently the China Center for Disease Control.

He has been invited as a keynote speaker for numerous international conferences and his current research interest is on cancer chemoprevention.

He is currently an Advisor to the National Water Research Institute (USA) and was the chairperson of the Expert Panel which advised PUB independently on the NEWater Study from 2001 to 2003 and is currently the Deputy Honorary Secretary of the Tan Kah Kee Foundation.