He had a long academic career devoted to public health, environmental and occupational health, and the relationship between ecosystem integrity and human health, mostly at the University of Alberta (Canada) and George Washington University (USA). He is currently an international consultant working through Medical Advisory Services, a small firm with offices in Rockville, Maryland, where his work convinced him that the unifying framework for what he was doing was sustainability. In 2015, he is on leave of absence as a Fulbright Visiting Chair at the University of Ottawa, in the Institute for Science, Society, and Policy. He is President-Elect of Sigma Xi, the international honor society for scientific research.