His area of expertise is environmental epidemiology. He has years of experience working as an environmental epidemiologist both in China and in the U.S. Qian's research areas of focus include maternal and child health, global health, environmental health, exposure assessment, indoor and outdoor air pollution. Most notably he was a key investigator on the study "Health Effects of Long-term Air Pollution on Lung Function and Respiratory Health in Children and Adults in Four Chinese Cities" sponsored by the U.S. Environmental Protection Agency under Annex 1 of the China-U.S. Protocol for Scientific and Technical Cooperation in the Field of Environment Protection from 1987 to 2001. Currently, Qian and his colleagues are building three large cohort studies in China.