Marsha Hanson is the coordinator for ACES Proficiency Tests at Stockholm University. ACES Proficiency Tests is part of the Environmental Monitoring Group at the Department of Environmental Science and provides proficiency testing in mainly water matrices with a focus on environmentally relevant parameters. Marsha has a background in chemistry and mathematics.

She began working with the proficiency testing team in 2010, taking over as coordinator in 2013. Before this, she worked at the department on a variety of research projects, performing environmental analyses in water, air, soil and biota. She is also a member of the Swedish Institute for Standards' committee for chemical water analysis.