Shanna Swan is a Mom on a Mission!

Shanna Swan is a Mom on a Mission!

January 22, 2023

By Dr. Shanna Swan, Professor of Preventive Medicine, Epidemiologist, Mom and Grandmother

Shanna was chosen as Healthy Child Healthy World’s January finalist for our 2023 Mom on a Mission® award. Read her first-person story below on how she became an advocate for children’s health. 

I have always been concerned about how my own environment affects my health and my family’s health. I’ve long been aware of big inequalities in environmental risks and the greater “hit” experienced by disadvantaged people in more highly exposed environments. I’m interested in how that affects health disparities. This led me to devote my life’s work to environmental health.

When my family and friends ask me what I do, I explain that I study how man-made chemicals affect the health of the developing infant. Since most of the hundreds of chemicals measurable in all of us are “silent” (I call them “stealth chemicals”) none of us know our “body burden. So we collect biospecimens–blood and urine, usually from pregnant women (because the developing fetus is the most sensitive of us all) in which we can measure these toxins. After birth, we carefully examine the infant (collecting measures of growth and development) and relate those measurements to their mothers’ body burdens. It is challenging work—in humans (unlike mice) we can’t conduct randomized trials and assign pregnant women to take a dose of bisphenol A (no ethical committee would permit that), so we can’t be sure that differences we see between infants born to highly exposed and less exposed women might not be the result of social factors or behaviors that led them to have higher exposure.

Despite challenges, we are making important progress. Work I did on demonstrating risks to pregnant women working in the semi-conductor industry from chemicals used in “clean rooms” helped get the worst solvents removed and standards tightened. Since 2005, when we published the first studies to show that higher exposure to some phthalates (chemicals that make plastic soft and flexible) can result in baby boys being less “masculine,” laws in the US and the European Union have banned the worst phthalates. Our most recent studies show that the levels of these chemicals in pregnant women have dropped 50%. This change is due to consumer’s choices and manufacturers’ response to those choices; I think our studies have helped people to make better choices.

Before I entered academia I worked for the California Department of Health Services responding to concerned citizens (most often moms) who worried about clusters of birth defects or miscarriages in their neighborhood. We listened and acted when we could, often conducting studies (such as the study of birth defects and miscarriage in a Santa Clara community whose water was contaminated by a leaky storage tank owned by a semiconductor plant). Those alert moms are the real Moms on a Mission, but they should not have to be. Nor should a parent have to do their own research to understand what chemicals are in her family’s food or household products. The manufacturers should be taking responsibility for testing these chemicals adequately, and our government should be making sure that they do. Until that happens, we will all be taking part in a large uncontrolled “trial” on a massive scale, a trial that no ethical committee would approve.

Know an amazing mom who is making a difference? Nominate her to be one of our Mom on a Mission® finalists! Learn more about Healthy Child Healthy World’s 2023 Mom on a Mission campaign by visiting A special thank you to our sponsors Ology