UF scientists focus expertise on environmental problem solving

Dr. Nancy Denslow

Dr. Nancy Denslow heads up research in the area of aquatic toxicology at the CEHT. (Photo by Mindy Miller)

In two small buildings a stone’s throw from the University of Florida’s gleaming towers of the Emerging Pathogens Institute and Cancer and Genetics Research Complex lies a hidden, rough-cut gem: the Center for Environmental and Human Toxicology, or CEHT. Inside, dedicated scientists work tirelessly to address the pressing environmental issues of today.

The problems they ponder, study and work passionately to solve often involve reconciling the conveniences of a contemporary, chemical-dependent lifestyle with the safety of our water supply, the integrity of our ecosystems and the health of our communities.

Chemicals are integral to modern life, from the mundane — furniture we sit on, clothes we wear, dishes we use for meals — to the essential, such as the foods we eat and the houses we live in. Even the latest staples of fashionable living, whether Starbucks coffee cups, Apple iPhones or anything by Under Armour are in some manner chemically produced. Recent events such as the Deepwater Horizon oil spill in the Gulf of Mexico, the Elk River release of a chemical foam in West Virginia and the Environmental Protection Agency’s release of coal mine waste in the Colorado River serve as reminders of ever-present chemical risks to the environment and public health.

The air we breathe, the water we drink and the food we eat all contain chemicals, yet, surprisingly, very little is known about the estimated 85,000 chemicals that the Environmental Protection Agency lists as currently being used commercially in the United States. How and where these chemicals are used and what their impacts are on animal, human and environmental health is all too often a mystery to consumers, regulators and sometimes to the product manufacturers themselves.

Analytical Toxicology Core Lab_MCM_4182

Rola Zeidan, one of Dr. Chris Vulpe’s graduate students, is shown at work in the Vulpe lab. (Photo by Mindy Miller)

In the face of these many unknowns, UF faculty members associated with the CEHT are working to understand the risks of chemical exposure for individuals, communities, home residences and the environment. The knowledge generated by these researchers is used by regulators, chemical producers and consumers to make informed choices about responsible chemical use.

“We help public agencies ensure that the technical and scientific approaches to evaluating (chemical) risk are undertaken using the best available science,” said Dr. Steve Roberts, longtime center director and a professor in the department of physiological sciences in the UF College of Veterinary Medicine.

The center has long been a source of environmental and toxicological expertise for decision makers at the local, state and national levels. For example, in 2001, Roberts and his CEHT colleagues were asked by state governmental officials to investigate the use of pressure-treated lumber in Florida playgrounds. Timber used to build the play structures had been treated with wood preservative containing arsenic — a known carcinogen — and center scientists found a critical weakness in previous risk assessments: There was no data on how much arsenic children actually receive from contact with the treated wood. Existing estimates of exposure varied widely, making it difficult to determine if using the wooden playgrounds put children at risk. In light of the errors uncovered by researchers at the CEHT, the U.S. Environmental Protection Agency decided to conduct a more in-depth assessment of risks to children from pressure treated wood, relying heavily on technical advice provided by the center.

Although they usually operate under the radar, CEHT scientists have occasionally made national headlines, as Andrew Kane, Ph.D., an associate professor of environmental and global health, did with his work on the Deepwater Horizon oil spill. The horrific size and scope of this disaster led to concerns about the safety of seafood in the towns ringing the Gulf of Mexico. Local fish, shrimp, blue crab and oysters are not only local dietary staples; they are the source of livelihood for many of these fishery-based communities. In response to safety concerns from gulf coast residents, a UF team led by Kane was mobilized to investigate possible effects of the Gulf oil spill on locally-caught and consumed seafood.

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Dr. Anirudha Giri, a former visiting professor at the CEHT, is shown at his computer. He visited UF at the invitation of Dr. Chris Vulpe and has since returned to India. (Photo by Mindy Miller)

The team quickly secured funding from the National Institute of Environmental Health to support its efforts and to launch the “Healthy Gulf, Healthy Communities” project in collaboration with community members.

Kane’s team investigated more than 1,000 individual seafood samples from the coastal waters of Florida, Alabama and Louisiana to determine that contaminant levels were remarkably low, and that edible portions of inshore-sampled seafood species did not have elevated contaminants. The scientists concluded that within three years after the oil spill, the seafood was as safe as it was prior to the oil spill. They further noted that the low level of oil-related contaminants that they did detect were not from the Deep Water Horizon spill.

A unifying theme of the CEHT is the understanding that human, animal and environmental health depend on one another and that the adverse impacts of chemicals on each are often remarkably similar. Center researchers are now confronting challenges emerging from the use of increasingly complex chemical compounds, such as nanomaterials, and their previously unsuspected adverse effects on reproduction, behavior, the brain and immune function. Center investigators are working to address these emerging issues in toxicology using integrative approaches considering the interrelated impacts of chemicals on human and environmental health. Together they are working to develop new chemical testing methods and alternative approaches that are faster, more accurate and more cost-effective as well as methods that minimize the use of animals.

Dr. Tara Sabo-Attwood, chairman of the department of environmental and global health in the College of Public Health and Health Professions, and Joseph Bisesi, Ph.D., a postdoctoral associate in that department, investigate how exposure to emerging contaminants of concern such as nanomaterials and phthalates that are present in consumer products such as cosmetics, electronics and plastics may lead to adverse health effects. They are probing how such agents impact the immune and gut systems in a way that enhances susceptibility to pathogenic infections. Their work uses mammalian and aquatic species, which model human and ecosystem health effects. Sabo-Attwood and Bisesi also conduct toxicology research abroad in Haiti and Kenya where there have been few studies of environmental contamination and exposure.

Dr. Nancy Denslow, a professor in the College of Veterinary Medicine’s department of physiological sciences and Dr. Chris Martyniuk are characterizing the effects of hormone-mimicking chemicals at multiple levels, from how they affect fish behavior to their activities inside cells. Martyniuk is pioneering new approaches to understand effects of these hormonal mimics on the central nervous system. Denslow, who leads the center’s Aquatic Toxicology Core Laboratory, developed innovative ways to assess the effects of chemicals based on the genes or proteins that are turned on or off in fish and many other species, and was among the first to document the problem of estrogens in U.S. waterways with wild fish. Denslow recently served on a Blue Ribbon Panel to assess contaminants found in reused water in California.

Dr. Chris Vulpe recently joined the center through UF’s preeminence initiative. His group focuses on identifying the common ways that all organisms use to cope with toxic chemicals. The Vulpe lab uses screening experiments that systematically test every gene in an organism to determine which genes are most important for tolerating the effects of a chemical.

Building on the momentum of the UF preeminence initiative, the CEHT is moving forward with plans for a new environmental health building, perhaps to rival its shiny neighbors, to provide the state-of-the-art facilities needed to continue to lead in animal, human and environmental toxicology. The center will be launching a fundraising campaign to marshal support for the new infrastructure, to enhance training opportunities and to help finance ongoing and new interdisciplinary community-based projects. Although perhaps a little more visible, CEHT scientists will still be quietly working to safeguard the inseparable health of our world — its animals, its people and its communities.

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