Site Assessment and Toxicology Section

Protecting Communities from Toxic Substances

Toxic substances that can harm people are found in Washington's water, air, soil, sediments, food, consumer products, and wildlife, including fish. Toxicology is the study of exposure to those toxic substances and their health effects, such as PFAS, PCBs, and phthalates.  

The Site Assessment and Toxicology Section evaluates potential health impacts from environmental contaminants in our state. We partner with local, state, and federal agencies, Tribal governments, universities, and local communities to prevent harmful exposures to toxic substances in the environment. We evaluate emerging issues, provide technical assessments, recommend protective standards, and issue public health advice. We also serve as science advisors to policymakers, provide information for the public on the web, and participate in community meetings. Our work informs communities, residents, health professionals, state agencies, and policymakers at the state and federal levels. 

Through our work, the Site Assessment and Toxicology Section is committed to addressing environmental health disparities for all communities, regardless of their background or location. We strive for environmental justice and health equity by identifying and addressing disproportionate exposures to toxic chemicals among sensitive groups and systemically oppressed communities. We work to improve the health of all people in Washington state by using science to inform policies and programs related to a wide range of environmental hazards and by infusing equity in our work. 

Our Programs

The Site Assessment and Toxicology Section has evaluated many environmental contaminants in Washington and takes action to reduce their potential negative health impacts. The following are some of our programs: 

Interagency Programs

Our toxicologists also collaborate with other local, state, and federal agencies on the following programs: 


Visit our resource pages for more information on a specific toxic substance or topic: 

Contact Us

Contacts for Site Assessment and Toxicology Section