Under the leadership of Dr. Russ Mauser MD, ScD, MPH, the Organic Pollutants Core brings together faculty with diverse backgrounds and interests to address the health effects of organics across the lifespan, with primary focus on fetal development through puberty. Our core faculty members have developed research that has been critical to addressing the public health impact of organic pollutants. As evidenced below, the core has a special emphasis on modern chemicals such as phthalates and historic chemicals such as polychlorinated biphenyls and dioxins. An important, but understudied, area in environmental health sciences is the potential adverse health affects of exposure to modern organic chemicals. Although modern chemistry and the subsequent birth of synthetic chemicals date back many decades, we continue to have a limited understanding of the potential public health impact of these ubiquitous chemicals of modern life. Chemicals are widely used in products of everyday life, such as in plastics to make them soft and flexible, in personal care products to hold scent and as a preservative, and in a variety of building products. They are also used in food packaging and processing materials and a variety of toys and products for babies and young children. Among the 80,000 or so chemicals of modern life, there is a subset that is hormonally active, defined as chemicals that alter endocrine signaling at low levels of exposure. As a result of altered endocrine signaling, there may be adverse effects on reproductive health, specifically fertility, as well as on pregnancy and birth outcomes. Recent studies indicate the presences of a variety of Pharmaceuticals and personal care products (PPCPs) in our water. Because there are thousands of PPCPs in common use, it would be impossible to conduct detailed field and laboratory studies on all compounds of potential concern. In order to help prioritize research on PPCPs, we developed a system for quantitatively ranking the environmental risks posed by individual PPCPs. This ranking accounts for gross production, human metabolism, removal by sewage treatment, and toxicity to human and ecological receptors. Using this ranking system, we have identified classes of pharmaceutical compounds of highest potential risk. Interestingly, most of these compounds have never been studied in the environment. In a follow-up study, we modeled the environmental transport and fate of a subset of these compounds using a multi-compartment box model (BETR-NA) that estimates the distribution of PPCPs between air, water, sediment, and uptake by aquatic biota. Similarly, we have identified previously unstudied compounds that may be of concern due to their environmental behavior.