See Current CV
Primary Research Interest
Endocrine disrupting chemicals (EDCs) are chemicals able to disrupt how hormones in the body normally act. Hormones are essential for development, maturation, fertility, and homeostasis throughout life. Perhaps not surprising then, exposure to chemicals that disturb their function has been shown to cause developmental and reproductive abnormalities, decrease fertility, increase obesity, cardiovascular disease, and various cancers in many different laboratory animal models. These same effects have been shown in wildlife populations and correlations have been shown for many of these chemicals/associated adverse health effects in humans.
Human exposure to EDCs rarely happens in isolation. Studies have shown that humans carry a body burden of up to 300 persistent chemicals in our bodies and that women pass many of these on to their children during pregnancy and through breastfeeding. Consumer products also rarely contain a single chemical, but typically several related chemicals. As such, we are regularly exposed to a suite of chemicals in our everyday lives, many of them able to interact with hormone receptors. I'm very interested in how these mixtures of chemicals are resulting in adverse health outcomes.
Hydraulic Fracturing/Unconventional Oil and Gas Development
Much of my dissertation work focused on the mixtures of EDCs used in the process of hydraulic fracturing/unconventional oil and gas development. Hydraulic fracturing involves the underground injection of large volumes of water, proppants (sand, beads, etc.) under high-pressure to stimulate fractures and liberate trapped natural gas and/or oil. Industry reports using more than 1,000 chemicals for this process across the US, and many of these are known or suspected EDCs.
My work on this topic has centered around testing suspected EDCs that are commonly used to determine which hormone receptors they interact with and whether they activate or inhibit these receptors. I have also worked on measuring these activities in surface and ground water in drilling-dense regions and have performed a developmental exposure experiment in mice, where pregnant mothers were exposed to likely environmentally relevant levels and health of their offspring was assessed throughout development. My overarching goals are to determine whether the EDCs used in fracking operations are contributing to elevated EDC exposure for residents near these operations and whether exposure may contribute to adverse health outcomes in humans and animals.
Adipogenic Activity of Indoor Contaminants and Potential Role of EDCs in Obesity Epidemic
Some EDCs, referred to as "obesogens", have been shown to increase weight and/or fat cell development in laboratory animal models. The prevalence of metabolic disorders, such as obesity, is currently of great concern. Obese individuals have an increased risk of type II diabetes, cardiovascular disease, hypertension, and other adverse health effects, which contribute to an estimated $215 billion in annual US health care costs. Despite increased attention and attempted interventions, US occurrence remain high: 9% of infants and toddlers, 17% of 2-19 year olds, and 38% of adults aged 20 and older are classified as obese.
My work on this topic at Duke has centered around testing suspected EDCs for their ability to drive lipid accumulation and/or fat cell proliferation (adipogenesis) in commonly-used mouse cell models. I spent the first several months of my postdoc assessing some of the commonly used cell lines and determined their relative strengths/weaknesses, and have now moved on to assessing the ability of various commonly-encountered indoor contaminants to drive adipogenesis. Further, our laboratory is interested in house dust as a potential exposure source for mixtures of EDCs, so I am testing whether house dust can drive adipogenesis and whether the ability to drive adipogenesis is associated with the metabolic health of children living in the homes where the dust was collected.