There once was a farming community in northern Michigan where a local chemical company prided itself on the production of two products: one, a nutritional supplement for cattle feed, the other, a brominated flame retardant. All was well until one fateful day when the deliveries of these two products were mistakenly switched, and the flame retardant was delivered to the cattle feed grain mill. The flame retardant was then unknowingly processed in the same manner as the cattle nutritional supplement and incorporated into the cattle feed. Unsuspecting people then drank the affected milk and ate the tainted beef. About 4,000 people ingested brominated flame retardant as a result, causing potential health implications which are yet to be determined. This was a public health disaster that Dr. Michele Marcus has devoted more than ten years to studying. "Many people in this community suffered not only the loss of their livelihoods but also suffered effects to their health. Learning about the health effects of exposure to this chemical can help us avoid exposure to similar chemicals in the future."

Dr. Michele Marcus is a reproductive and environmental epidemiologist currently serving as Acting Chair of the Epidemiology Department. She is Director of Graduate Studies in the Department of Epidemiology and has a joint appointment in the Department of Environmental and Occupational Health in the Rollins School of Public Health. Her work includes studies of prematurity, low birth weight, congenital malformations, child growth and pubertal development, adolescent pregnancy, miscarriages, menstrual function, fertility, and menopause. She has also explored the health effects of military service, exposure to electromagnetic fields, bisphenol A, phthalates, and gene-environment interactions. She is currently serving on a National Academy of Sciences Institute of Medicine Committee evaluating the ongoing health effects of Agent Orange exposure among Vietnam Veterans. "I am interested in understanding how genes and the environment interact, particularly with respect to reproduction and the endocrine system," says Marcus.

The farming community incident has provided Marcus with useful insights into the environmental hazards of human ingestion of endocrine-disrupting chemicals. She found that the daughters who were exposed in utero and through breast feeding have had earlier menarche, the onset of menstruation, than other girls who were not exposed. This research is the first time anyone demonstrated that an environmental exposure could affect menarche, a finding which may explain why girls are maturing earlier now than in the past. She and doctoral student Kira Taylor also found that the genetic influence on menarche was weaker in those exposed to the chemical than those not exposed. In other words, a gene-environment interaction occurred. She hopes to continue to follow this community to assess whether there is a multigenerational transfer of health effects resulting from this environmental exposure.

Marcus does not work alone but actively seeks out interdisciplinary collaboration. Much of her epidemiological research considers the interdependence of genetics, the environment, and the end outcome—health. Marcus states, "If you put together environmental exposures with genetics, you can hone in on those who may be more susceptible to the exposures, and you can also understand the mechanism by which the environmental exposure and the genes create health effects downstream."

Such interdisciplinary collaboration may now be easier, thanks to a new interdisciplinary PhD program Marcus and co-principal investigator Ken Brigham, Professor of Medicine, are about to launch with a 2.5 million dollar grant from the Burroughs Wellcome Fund. When it gets underway, "Molecules to Mankind" will train PhD students and post-doctoral fellows in laboratory and population-based sciences. The program will have four tracks, including one involving gene-environment interaction, co-led by principal investigators Marcus and Stephanie Sherman, Professor of Human Genetics. Marcus can hardly contain her enthusiasm about the program: "It's absolutely awesome," she says. "When you work with people in different fields, it's just unbelievable how much you get to learn. This training program will not only lead to scientific advances made by our trainees, but will be lots of fun for all involved."

As the Director of Graduate Studies for the Epidemiology PhD program, Marcus also hopes to flavor existing public health programs at Emory with some cross-disciplinary training. Says Marcus: "Sometimes we get very insular and we have assumptions about how we approach things. If someone from a different field says ‘Why do you do it that way?' it can be helpful to step back and consider that maybe there's another way to do it." Her appreciation for innovative student learning and student contributions spills over into everything she does. "We get ideas from each other," she says of her students. "There was a Talmudic scholar who said, I've learned much from my teachers, more from my colleagues, but I've learned most from my students.' I really feel this way."

Marcus embodies Emory University's mission to inspire open disciplinary boundaries. But this pioneer in gene-environment interaction research is interested in more than just science. She also sings, composes music, and assists with the operation of a family business, "The Music Class," an early childhood music education program. Her basement holds a small recording studio, where Marcus and her husband, Rob Sayer, compose and record original music with their two children. Call it a new kind of interdisciplinary collaboration.