The Environmental Health Sciences Center was founded at Oregon State University in 1967. At that time, the research focus was on agricultural pesticides. Through this foundational research, the Center developed a strong research base in aquatic toxicology, a strength that continues today in the Aquatic Models Facility Core. Furthermore, EHSC investigators identified novel instrumentation and methods in mass spectrometry to analyze complex samples and thereby understand human exposure. The results of this work are exemplified by the Chemical Exposure Core, wherein passive sampling devices can detect 1,530 environmental chemicals. These chemicals and chemical mixtures can then be evaluated in the zebrafish model to determine potential health effects.