EXPOSURES IN EDEN
Hot dogs, power lines and bad air are just a few items on the ever-growing list of possible environmental factors that may adversely affect your health.
by Monika GuttmanIt was the early '60s, when the United States was both enamored with the potential of nuclear power and thrashing through the worst of the Cold War. John Peters, M.D., was on his way to
becoming a surgeon when duty-in the form of the U.S. Army-called. Peters spent the next several years cold, if not at war, serving as the medical examiner for soldiers living under the ice caps of Greenland with experimental mobile nuclear reactors. Out went his dream of wielding a scalpel, he says, and in came a lifelong fascination with the health impact of environmental factors like radiation. What attracted him most, he says, was the Sherlockian task of "finding links that we can potentially reverse."
Southern California is a long way from Greenland, but Peters is still hot on the trail of environmental causes for illness. These days he has the opportunity to look at human health effects from environmental exposures on a grand scale. A five-year, $5 million grant from the National Institute for Environmental Health Sciences (NIEHS) established a new Environmental Health Sciences Center at the USC School of Medicine. Peters is director of the Center, which includes 40 scientists with a long history of research and an established commitment to environmental health problems. Their goal: identify substances in the environment that cause disease and determine how and why factors such as genetics make some people more susceptible to these diseases. Among the areas of focus: air pollution (indoor and out), pesticides, aflatoxins (toxic products that come from fungi), radon, passive smoking, bioaerosols, magnetic fields and nitrites.
"As long as diseases of unknown cause exist, it seems to me we really have to think that the environment could be part of the causation," explains Peters. "On a broad scale, the cause of illness has got to be either genetic or environmental, depending on how we define environment. So it's worth searching for the causes of these diseases."
The search for these agents will be conducted not only by scientists representing a wide variety of disciplines-basic sciences like physiology, molecular biology, genetics, chemistry and engineering, plus exposure assessment and statistics-but also at three separate Southern California universities: USC, UCLA and the California Institute of Technology. Such multi-campus interaction, says Peters, puts the Center on the cutting edge of emerging trends in the research community and allows greater exploitation of the diverse strengths of each institution. For example, a study under the auspices of the Center will investigate environmental tobacco smoke (passive smoke) utilizing investigators from UCLA's aerosol research laboratories and the USC air pollution research team.
"It's important when dealing with environmental issues, to have a multidisciplinary effort because of the nature of the problems," says John R. Froines, Ph.D., professor, UCLA School of Public Health and associate director of the Center. "We have enormous strengths scientifically in Southern California and we haven't brought them together the way we should have in the past. Hopefully, now we have some of the resources we need to cross disciplines and cross distances."
What really sets the USC-based Center apart from the 18 other NIEHS environmental centers nationwide-including centers at UC Berkeley, Harvard and New York University-is that instead of focusing on laboratory or animal models, the emphasis here is on humans. In fact, one of the appeals for situating the Center in Southern California is its large, diverse population, which allows researchers to look at cultural and genetic variables that might affect risk. "We expect that this strong epidemiological focus, combined with significant expertise in exposure assessment and biomarker development, will provide exciting advances in our understanding of diseases and disorders having an environmental etiology in the coming years," says Kenneth Olden, Ph.D., director of the NIEHS. Adds Froines, "I want to emphasize that we want to try and improve environmental health for people. The Center will have positive social consequences."
Among the research already underway are several studies looking at the chronic health effects of ambient air pollutants on children. Another study, led by Anna Wu-Williams, Ph.D., associate professor of preventive medicine, seeks to identify risk factors for lung cancer in non-smoking women. Little is known to date about the causes of lung cancer in nonsmokers. In addition to passive smoke, other factors being considered include the role of indoor air pollution, the relationship between the intake of vegetables and fruits and lung cancer risk, and the relationship between family histories of cancer or previous lung disease and lung cancer.
Another study will look at dietary and lifestyle risk factors for cancer in four ethnic groups: African-Americans, Hispanics, Japanese and non-Hispanic whites. Other studies will look at the relationship between solar radiation and melanoma, the relationship between low-dose X-rays and acute myelocytic leukemia, and will try to map clusters of cancer by census tract to pinpoint potential environmental causes for illness.
Some researchers in the Center want to advance the study of toxicokinetics, which Peters describes as the identification of where a chemical goes in the body and what happens to it, along with biomarkers, which are the internal measures of exposure or response. "Ultimately we would like to know what the exposure is at the cellular level," says Peters. "For example, nitrites from hot dogs are changed in the body to other nitrogen compounds, but what are the compounds and where are they concentrated?"
Although it would seem that, after years of media coverage linking pollution to health hazards, the public would readily embrace information about environmental causes of illness, Peters says the opposite is true: the
new Center faces some of its greatest challenges proving that people are indeed affected by their environment. "I've been in this field for 30 years," he says. "In some ways environmental awareness and interest on the part of the public and politicians was probably higher maybe even 15 or 20 years ago than it is now." That high level of interest, he says, generated a number of possible associations between the environment and disease, many of which have not panned out. "It has resulted in the public getting fed up with the latest 'connection,' to the point where they don't believe them any more. So I think that is a major concern of our Center. We'd like to get to the point of being more certain about these connections."
To achieve that certainty, the Center, which is divided into five research "cores," has devoted two cores specifically to methodology: one in study design, epidemiology and statistical methodology, and one in exposure
assessments. The goal, says Peters, is to pinpoint as accurately as possible exact causes and effects. To date, for example, exposure assessment has been characterized by putting people into categories of "exposed" or "unexposed," or perhaps "high, medium and low" exposures, he explains. "The real goal is to get a quantitative measure of somebody's exposure. For example, if we look at air pollution in Los Angeles, it would be more informative to know what everybody's total lifetime exposure to ozone has been, or to airborne particles, or to nitrogen dioxide. Or finding a better way to assess alcohol intake than by asking a large cohort of people how much they drink."
Another assessment improvement-identifying subpopulations that may be at higher risk than the general population, or those with a genetic predisposition to a certain illness-will "help us be more certain about connecting an environmental exposure to a health outcome," says Peters, "so we know what agent is doing the damage and how it is doing the damage." For example, establishing that a genetic predisposition to asthma is exacerbated by living in areas with a certain level of particulates in the local air could help families avoid serious health problems.
Peters sees current research that seeks to establish genetic and hormonal links to everything from cancer and diabetes to obesity and violence as complimentary to the studies that will come out of the new Center. Although recent research has focused on the role of exogenous and endogenous hormones in breast cancer development and prevention, for example, new studies examining the possible relationships between electromagnetic fields, pesticide exposure or alcohol consumption and breast cancer risk are generating growing interest. He balks at relying solely on genetic explanations for disease. He says, "For now, we can change our environment a lot easier than we can change our genes."
One of the Center's ultimate goals will be to find steps that can be taken to reduce environmental illness. Says Peters, "There may be host factors, such as nutritional status. If you eat a lot of vitamins and you're well nourished, you may be more resistant to breathing ozone in Los Angeles." Through research at the Center, he says, "We hope to find not just the cause of problems, but those elements that increase resistance as well."
The three other research cores of the Center are respiratory effects of environmental exposure, environmental exposure and childhood cancer, and environmental exposure and adult cancer. These will be supported by four shared service core laboratories. Robert Haile, Ph.D., professor and director of Biological Sample Processing, one of the service core laboratory, says being part of the Center will "give us much better visibility and a mechanism for collaborating with each other. We'll have one state-of-the-art, standardized place for a specific service, with a lot of experience and data management, so researchers can rest assured it's being handled right."
Ideally, those behind the new Center hope it will not only discover links between environmental factors and illness and recommend specific changes to avoid disease, but that it will also attract new researchers and investigators to the field. In addition to a strong emphasis on funding new young researchers, the Center will sponsor monthly seminars from each of the research cores, will hold workshops in environmental health and will sponsor visiting professors. "There are people doing work that is relevant to environmental health, but they don't realize it's relevant," says Peters.
"Because of the Center, they will. There will be more interaction, more disciplines, more people in different departments involved. Eventually, we can change the nature of what they're doing to focus more on environmental health problems. That's the real reason for the Center being here."
Another goal of the new Center is to make headway with the community-serving as a resource for community organizations dealing with local pollution problems, as an information clearing-house, and as a possible consulting source for investigating local environmental concerns. One of the first such projects was to work with California State University Los Angeles educating California high school science teachers about teaching environmental health. Another planned project is to examine lead poisoning among residents of the "Alameda corridor," a heavily-industrialized area in southeast Los Angeles County.
On a larger scale, Peters is hoping the establishment of the human-oriented Center means a significant shift in focus in environmental research. "I guess I'm probably biased, because I've always been interested in and doing studies on the health outcomes on people," he says, smiling. "The institute that has funded us has a tradition of being much more interested in laboratory-based studies and less interested in human-based studies-epidemiology. That's changing. And I think maybe we came along at the right time."