Environmental scholar Jun Ui, known for his series of public lectures on pollution and his involvement in a number of antipollution movements, died early Saturday at a Tokyo hospital, his family said. He was 74.

Ui was known as an "activist scholar" for such efforts as forming a network of environment conservationists in Okinawa and giving advice in a civil lawsuit in a Niigata mercury poisoning case.

Ui joined the faculty of engineering at the University of Tokyo as an assistant in 1965 and was involved in investigations into the Minamata mercury poisoning and pollution cases in Europe as a researcher for the World Health Organization.

Based on these experiences, he opened his classroom at the university to the public in 1970 for a series of lectures on the "principles of pollution."

About 20,000 people are estimated to have attended the lectures through 1985 in which he talked about the importance of the viewpoints of ordinary people rather than those of the authorities and corporations, in addressing pollution issues.

His lecture notes were used as guidelines by organizers of antipollution movements and had a considerable impact on various other citizens' movements.