Penn Loh is Professor of the Practice at Tufts University's Department of Urban and Environmental Policy and Planning. From 1996 to 2009, he served in various roles, including Executive Director since 1999, at Alternatives for Community & Environment (ACE), a Roxbury-based environmental justice group. He holds an M.S. in environmental science and policy from Energy and Resources Group of the University of California at Berkeley and a B.S. in electrical engineering from MIT. Before joining ACE, he was Research Associate at the Pacific Institute for Studies in Development, Environment, and Security in Oakland, California and a Research Analyst at the Tellus Institute for Resource and Environmental Strategies in Boston. He has published broadly on environmental and social justice issues. He has served on the National Environmental Justice Advisory Council's Health and Research Subcommittee, the Massachusetts Environmental Justice Advisory Committee, and on the boards of the Environmental Support Center, the Environmental Leadership Program, and Community Labor United. He is currently a board member of the New World Foundation and the Massachusetts Energy Facilities Siting Board.