A state environmental agency has delayed for a week its final decision on approving one last portion of Harvard's $110 million Medical Area power plant because the agency needs time to evaluate new information on the possible health effects of an air pollutant the plant will produce.

Studies and health experts' opinions gathered by the Division of Air and Hazardous Materials indicate a possible need for stronger controls on nitrogen dioxide emission from the plant than the division had previously considered necessary. Donald Squires, an air pollution control engineer in the division, said yesterday.

The division now plans to announce its final decision on Monday. It had originally planned to issue the decision yesterday.

Nitrogen Oxides

Although most of the plant is already under construction, work on its electrical generators, which will produce nitrogen oxides, cannot proceed until the state approves them.

The plant is designed to provide steam, chilled water and electricity at a savings to the Medical School and affiliated hospitals.

Squires said the pollutants the generators will produce may pose "pretty serious health problems."

Frank Lily, who is working on a draft of the division's decision, said the draft has run to 100 pages. He declined to describe the draft's contents.

Edward Lashman, the University's director of external projects, said yesterday the division's delay is "a little disappointing."