Carol D. Litchfield, 75, a research professor at George Mason University’s department of environmental science and policy, died April 3 of pancreatic and liver cancer at her home in Arlington County.

Her death was confirmed by a friend, Jean Kenney.

Dr. Litchfield joined GMU’s biology department in 1993. Since 2005, she had been a research professor in the department of environmental science and policy. She officially retired 18 months ago but continued to teach part time.

Carol Ann Darline Ross was born in Cincinnati. She was a graduate of the University of Cincinnati, where she also received a master’s degree in biochemistry in 1960. She received a doctorate in organic biochemistry at Texas A&M University in 1969.

She was a research scientist at Texas A&M, a faculty member in the microbiology department at Rutgers University, and a senior environmental scientist at DuPont in Wilmington, Del., before moving to the Washington area and joining the GMU faculty.

Her husband of 47 years, Dr. Charles C. Litchfield, died in 2007. She had no immediate survivors.

— Bart Barnes