Science as a whole does not always begin in a laboratory. Often, it begins with questions raised by communities: “Is something in our environment affecting our health? What are we being exposed to, and what does it mean for our families?” The 2026 SOT Regional Interest Session “Chemical Exposures and At‑Risk Populations in California” highlighted how biomonitoring across the state is being used as science in action, or research that is responsive to lived experience and grounded in real‑world concerns.
A unifying theme across the session was this idea of responsive science. While not every study was initiated by a direct community request, nearly all were motivated by known or suspected exposure problems and designed to inform decisions outside the laboratory. This could include matters such as policy, regulation, prevention, or even just community awareness. In each case, scientific tools were applied to questions that matter in people’s day‑to‑day lives.
The first presentation by Xiaowen Ji, CalEPA Department of Toxic Substances Control, demonstrated how exposure science is evolving to address difficult and deeply human public health challenges. By examining amniotic fluid, researchers used advanced chemical analysis and machine learning to explore links between environmental exposures and birth defects. The work did not rely on a single known chemical culprit; instead, it looked for biological patterns that could help explain how complex mixtures of exposures may interfere with fetal development. This approach reflects science responding to an urgent need for better tools to understand environmental contributors to pregnancy outcomes.
Other talks more directly reflected studies shaped by community concern. For example, Jill Johnston, University of California Irvine, discussed one of her projects focused on California’s “dirty little secret,” a longstanding issue that is hidden in plain sight across Southern California. Her talk focused on investigating Los Angeles neighborhoods situated near active urban oil drilling. Her team of researchers worked with residents to assess metal exposures using toenail clippings, an accessible, noninvasive sampling method well-suited for community-based research. The findings revealed patterns of exposure associated with nearby oil and gas production, translating longstanding local concerns into biological evidence. Her next steps are to try to solidify whether her findings of oil and gas production–specific exposure signatures can be more directly linked with the health concerns that these communities are experiencing, which could lead to policy changes or intervention strategies in the future.
In California’s San Joaquin Valley, Aalekhya Reddam, OEHHA, focused on families living in a region with some of the nation’s worst air quality. By measuring air pollution biomarkers in both children and parents, they found widespread exposure to multiple pollutants and strong similarities within households. These results highlighted how children experience environmental exposures alongside adults. It also raised important questions about everyday exposure sources, including those inside the home, leading to some interesting audience discussions.
The session closed with a powerful reminder of how responsive science must continue beyond data collection. Fire Captain Heather Buren, San Francisco Fire Department (SFFD), discussed biomonitoring work focused on firefighters, an occupational group whose exposures are inseparable from their roles in protecting communities. What made this project interesting to discuss was its story and particular focus on female firefighters during a time where the SFFD started to see an increase in younger female firefighters being diagnosed with reproductive cancers. This led to a call-to-action response where first responders had a lot of questions and needed help from scientists to get answers that required a fully collaborative approach. Her presentation emphasized that how data are shared, understood, and trusted is just as important as how they are collected. Her emphasis on the importance of having the community involved in every step of the process was inspiring. Clear communication and thoughtful report‑back can transform biomonitoring results from numbers on a page into tools for awareness, advocacy, and improved protections for those on the frontlines.
Together, these talks illustrated that biomonitoring in California is not just about measuring chemicals, but about responding to real conditions on the ground. By linking lived experience with scientific evidence, this work shows how exposure science can move beyond description and toward understanding, action, and protection, both in California and in communities facing similar challenges elsewhere.
This blog reports on the Regional Interest Session titled “Chemical Exposures and At‑Risk Populations in California” that was held during the 2026 SOT Annual Meeting and ToxExpo. An on-demand recording of this session is available for meeting registrants on the SOT Online Planner and SOT Event App.
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