Dr. Hatakeyama is the Director General of the Asia Center for Air Pollution Research (ACAP), which is the Network Center of the Acid Deposition Monitoring Network in East Asia (EANET). He was a Research Scientist at National Institute for Environmental Studies, Japan from 1979 to 2007 and was a Professor at Tokyo University of Agriculture and Technology from 2007 to 2016. In both places, he engaged in research on atmospheric chemistry.
In the early stages, he conducted experiments on atmospheric chemical reactions by use of a large smog chamber, but in the later stages, he mainly focused on observations of air pollutants. Particularly, air pollution transported long-range from East Asia was his main target. He carried out observations of gaseous pollutants and analyses of chemical composition of aerosols by aerial and ground-based observations. After retiring from university, he has been engaged in work that provides an overview of air pollution in Japan and East Asia, as well as work that supervises research funds related to environmental research in Japan.