Beachcomber tracks marine toxins in Florida.
Photograph by Christian Howard / Rosenstiel School of Marine and Atmospheric Sciences at the University of Miami
Photograph by Christian Howard / Rosenstiel School of Marine and Atmospheric Sciences at the University of Miami
Epidemiologist Lora Fleming ’78, M.D.-M.P.H. ’84, tackles breathing, cancer, and unexpected days at the beach. At the office, she directs research on a database of 3 million cancer cases, or culls morbidity factors among blue-collar workers across the country. Other days she may find herself swabbing the noses of asthmatics exposed to Florida red-tide toxins. Not too long ago, she and a colleague spent a morning chasing after dogs that had defecated on a Miami beach. “That was part of the recreational microbes study—or, as we call it, the ‘poop in the water’ study,” she explains. Even trickier than corralling the canines was “figuring out how to get the damn seabirds to go on the plastic we had laid out for them. Then some bird guy called us from Mississippi and said, ‘I have two words for you: “Cheese Doodles.”’ They eat the doodles and poop, apparently.”
Fleming’s aplomb sometimes shields the fact that she is among those at the top of the somewhat esoteric field of studying oceans and human health. Collecting the specimens contributed to a larger study on microbes in ocean waters. “People have done this kind of work for chlorinated pools in the past,” she says, “but this is the first time that such a study has been done for a marine environment in subtropical and tropical areas. We want to know: what are the inputs when you do not have an obvious sewage outflow? The big one is through runoff, but there are also inputs from birds and other wildlife, domestic animals—and humans. The hypothesis is that people who go into the water will have a higher risk of reporting a range of diseases, and that that will correlate with the levels of microbes we find in the water near their mouths.”
Growing up in Boston, Fleming spent summers on the North Atlantic coast, sailing, swimming, and collecting clams and mussels from the local beach for dinner. She no longer eats raw shellfish—and even tries to avoid it when cooked—because of potential bacterial and viral contamination. But she remains enthralled by everything oceanic.
Miami became home in 1989 when she and her husband, marine biologist Mauricio Ortiz, moved there for his doctoral studies. (He now monitors fish populations for the federal government.) The region has proved a natural fit. On family vacations, they often sail the Caribbean, where Ortiz and their daughter, an aspiring oceanographer, scuba dive while Fleming skims the surface in her snorkel gear. “They make fun of me because I’m not a diver: there’s a big hierarchy there,” Fleming says. “I love snorkeling because it’s low-tech—put the mask on and get in the water.”
At work, her joint appointment at the University of Miami’s Miller School of Medicine and Rosenstiel School of Marine and Atmospheric Science necessitates wearing several professional caps. She is the medical director of Florida’s Cancer Data System, the second-largest registry behind California’s. She also co-directs research on occupational health, funded by the National Institute of occupational Safety and Health, using information that has been collected since 1957 through the National Health Interview Survey. The survey uses data from random samplings of citizens each year to track trends in illness and disability and to gauge progress on national health objectives. “All I can say is: it’s great to be white and male and professional,” she remarks. “The socioeconomic influences on health are just huge.”
Fleming has a keen interest in children’s health as well; she completed her medical residency in family medicine before earning a doctorate in epidemiology from Yale in 1997. A small pilot study that she was involved in examined arsenic exposure rates for children using wooden playground equipment preserved with copper, chromate, and arsenic (CCA), a common rot-retardant. Results showed that children “do get arsenic on their hands, which travels to their mouths and into their bodies,” she says. “This work needs to be followed up because children continue to be exposed.” CCA-treated wood is now prohibited for new residential use (although existing wood does not have to be removed), but it is still used widely in marine environments, where it affects ocean life.
At the university, Fleming also co-directs one of only four oceans-and-human-health research centers in the country funded by the National Science Foundation and the National Institute of Environmental Health Sciences. Established in 2004, the center helps promote research, devise curricular material for schools, and develop public information. “Until [the center] was funded, it was unlikely that researchers from various parts of oceanography and public health worked together,” she notes.
Such cooperation has been essential to Fleming’s groundbreaking work on how humans are affected by Florida red tide. These groupings of harmful algal blooms (HABs), first documented scientifically in Florida in 1947, are composed of single-celled organisms called Karenia brevis. “Red tides happen throughout the world,” Fleming explains. “This particular organism likes to live in the Gulf of Mexico. Other organisms cause different red tides elsewhere.” Karenia brevis, which is relatively fragile, breaks apart easily in the surf, releasing brevetoxins into the water and often into the air; these have been blamed for killing thousands of fish, as well as numbers of manatees and dolphins, and for causing human illness.
Researchers are trying to figure out why the organism blooms, why it produces toxins, what it feeds on, and how to better predict where and when such HABs will turn up, Fleming explains. “The HAB community is convinced that HABs are increasing worldwide. Are we humans making these blooms occur more often? Is global warming producing more frequent or more longer-lasting blooms? For me, the questions are: is there really an increased number of blooms, and are they causing an increase in human-health effects? It turns out these are not easy to answer, because there is very little surveillance going on and we don’t have a good baseline in human populations.”
Fleming and an interdisciplinary research team (toxicologists, veterinarians, physicians, and oceanographers among them) are in their sixth year of studying the phenomenon. She looks specifically at the effects of aerosolized Florida red tide neurotoxins on a group of about 120 asthmatics in Sarasota (a separate Centers for Disease Control study also monitors non-asthmatic lifeguards), assessing their respiratory functions and symptoms before and after beach exposure both during and apart from red tides.
“We have found that the Florida red tide definitely increases asthma in asthmatics,” she reports. “Acute exposure for one hour—or even less—at the beach is all it takes. We have also shown that in areas where Florida red tide is a frequent event, there are even increased admissions to the emergency room for pneumonia, bronchitis, and asthma during red tides. Now we’re looking at more sub-chronic effects, such as the development of pneumonia.” Her colleagues are exploring other effects, such as on placentas, fetuses, and breast milk in animals. “We also want to look at interventions,” she says. “I’d like to leave the community with something they can use—tell them what they can do” to ease or prevent harmful effects.
At the same time, Fleming points out that Karenia brevis is apparently not all bad. Her fellow investigators on the study, Daniel G. Baden and Andrea Bourdelais of the University of North Carolina-Wilmington, and their team of researchers, have discovered that the organism also produces its own “anti-toxin,” which, when given to sheep, stopped the brevetoxin from causing asthma. “It turns out that this ‘brevenal’ is 1,000 times more powerful than any other drug” for easing mucous conditions in the lungs of sheep, and “has been patented for future use in drug trials with people who have cystic fibrosis. This was a serendipitous finding,” she adds. “We don’t even know why these organisms produce this anti-toxin.”
Baden, formerly of the University of Miami, was among those who first encouraged Fleming to study marine and freshwater toxins. Initially she worked on ciguatera fish poisoning, “a really nasty” illness caused by eating fish (including grouper, barracuda, amberjack, snapper, hogfish, and kingfish) carrying toxins produced by a marine microalgae, Gambierdiscus toxicus, that blooms on coral reefs where fish feed. “[Victims] often don’t get diagnosed,” she notes. “They have pain in their teeth, pain during intercourse, they are fatigued, and people just think they are crazy, when it’s really ciguatera. Then, after a while—weeks, months, even years —the symptoms go away. We think the toxin continues in the body, but nobody has really looked at that.”
Fleming’s efforts on all fronts last year earned her an academic award as Florida’s “Outstanding Woman in Public Health.” She credits her successes to a collaborative approach and a management style that entails “learning when you are supposed to be in charge and when you need to let other people be in charge and do what they are good at.” She also thrives on interdisciplinary research. “I like to do new things,” she says, “and to feel a little out of my depths at all times, so I can say, ‘I have no idea what you are talking about’—and then learn something new!”
She admits that collaboration has its challenges. In the Oceans and Human Health Recreational Microbes Study (“poop in the water”), for example, the research team spent several hours defining “splash zone”—within which the ocean water slides back and forth on the shore—so they could all understand and measure the same span. The most detail-oriented researchers become irritated when the “big ideas” people wave their hands around while making grand statements, Fleming reports. “You put the oceanographers and the biomedical people in the same room, and boy, do they think in different ways. The oceanographers have remote sensing data on the whole Florida coast, and I’m there talking about 10 people breathing on a beach. The key is somehow linking all of these people together and benefiting from each others’ science, and tolerating each other—a little bit like what the United Nations does.”
In that vein, Fleming has pointedly hired and mentored women and minorities throughout her career. (She is fluent in Spanish: she and Ortiz, a native Colombian, met while he was doing research in the Amazon and she was vacationing there as part of an Earthwatch program.) “There is still a glaring dearth of women and minorities across all the sciences,” she says. “Women in engineering, for example, are scarcer than hen’s teeth. I have also mentored young men, but if I have to choose between two people who are equally good, I will often choose the woman or the minority scientist because I think they have a harder time finding appropriate mentorship.” Her research groups, by design, have a wide range of ages and expertise: students, young faculty, veteran investigators, public-health department workers, and even members of grassroots groups.
That policy has the potential to yield better, richer science, she asserts. Her collaborative research projects based on the National Health Interview Survey “have shown that blue-collar workers and minorities and women workers are way behind the eight ball in terms of public health—they have less insurance, more obesity, higher tobacco exposure, and they are screened less for cancer and other diseases,” she says. But then she notes that a young African-American colleague, Katherine Chung ’94, suggested that the research group also look at occupational segregation by race in terms of its effect on respondents’ self-rated health. “It turns out that both white and black U.S. workers rate their health better if they are in a non-segregated workplace,” Fleming says. “If you ask me, that’s where we need to go as a society. If we don’t have interdisciplinary research and people like Katherine Chung asking these questions, then they won’t be asked. We need people in science who can look at old problems in a new way. We need to be inclusive. It’s the American way.”
~Nell Porter Brown