Marit Woods Thorson, 90, a longtime advocate for children, the elderly, the poor and the disabled, died Oct. 16 of emphysema at Rockville Nursing Home. She was a Bethesda resident.

From 1973 to 1981, she worked as director of volunteer services in Montgomery County. As director, she developed a program to publicize the need and opportunities for volunteers, established a student placement service in nonprofit organizations and arranged volunteer service for more than 200 public and private agencies.

Mrs. Thorson was born in Finspong, Sweden, and came with her family to the United States at the age of 6 months. She grew up in Altoona, Pa. In her late teens, she lived with relatives in Stockholm and Bonn, where she witnessed Nazi book burnings. She was so outspoken about what she had seen that her relatives had to get her out of the country.

Back in the United States, she attended Antioch College in Ohio and in 1939 received a bachelor's degree in business administration from the University of Tennessee. After graduation, she moved to New York City and took a job with New York University.

She and her husband lived in Arlington during World War II and moved to Bethesda in 1947, where she volunteered with various social service agencies. From 1958 to 1961, she was chairman of the Montgomery County Health and Welfare Council. She also was legislative chairman of the county's Youth Commission and served as the Maryland delegate to the 1960 White House Conference on Children and Youth. During sessions of the state legislature, she made frequent trips to Annapolis to lobby for legislation and funding.

While her three children were young, she was active in Montgomery County Democratic Party politics, starting as a precinct chairman. In 1962, she was chairman of the county Dollars for Democrats campaign, which raised a record amount. She ran for the Maryland House of Delegates in 1966, losing narrowly in a Republican sweep.

In 1970, when her children were nearly grown, she received a master's degree in social work from Catholic University.

Survivors include her husband of 64 years, Phillip Thorson of Bethesda; three children, Ingrid Mongini of Bethesda, Louise Thorson of Providence, R.I., and Erik Thorson of Nashville; and five grandchildren.