Mallery Downs grew up in Shawnee Mission, Kansas, and Silverton, Colorado. She moved to New Mexico in 1978 and entered Highlands University in Las Vegas in 1982. Later she transferred to the University of New Mexico, where she received a Bachelor of Science in 1987.
    Mallery began her nursing career with the Indian Health Service in Acoma. She also worked as a frontier nurse in Montrose County in southwestern Colorado and as a discharge planner and health promotion specialist in Farmington, New Mexico, for eight years.
    She is still a registered nurse, currently working as program manager for the Community Environmental Health Program at the University of New Mexico's College of Pharmacy. She does federally funded, community-based environmental health research.
    Mallery joined the New Mexico Public Health Association (NMPHA) in 1993. She has served as president and is currently treasurer. Over the past several years she has participated in working groups on the precautionary principle, which seeks to protect public health and the environment from uncertain risks, along with investigations of the effects of mercury, climate change, and dairies in New Mexico. She also served on a working group that studied opportunities for sustainable agriculture.