Environmental health seems to have little to do with Los Angeles, a metropolitan area popularly synonymous with smog. Despite much progress, southern California continues to suffer the worst air pollution in the United States, and the nation's most ethnically diverse region is also among the most heavily industrialized. However, three leading universities in the Los Angeles area have joined forces to study the effects of air pollution and other environmental factors on human health. Faculty from the University of Southern California (USC), the University of California at Los Angeles (UCLA), and the California Institute of Technology (Caltech) make up the Southern California Environmental Health Sciences Center (SCEHSC) personnel. The center comprises five interdisciplinary research cores, four service cores, and a community outreach and education core. Two overarching themes are apparent in the center's research--the epidemiology of environmental effects on human health and gene-environment interactions.
![SCEHSC building](niehsbuilding.JPG)
Source: NIEHS
![Director Dr. Peters](niehsfigpeters.JPG)
Center director John Peters
Source: NIEHS |
Smog itself provided an impetus for the center's formation, explains John Peters, center director and chair of occupational and environmental health at the USC School of Medicine. Peters, who also serves as director of the respiratory effects core, was amazed that the effects of long-term exposure to air pollution in southern California had never been assessed in a comprehensive way. "Given the fact that we've had air pollution for 50-plus years, there hadn't really been a first-rate study done to see whether there are chronic, permanent effects," he says. A funding opportunity from the state of California offered Peters and his colleagues a chance to take on that challenge. In developing their study, they needed further expertise, which led to consulting with researchers at Caltech and UCLA. "That helped establish the fact that we could bring together a unique collection of scientists with different interests, ranging from engineering and chemistry to epidemiology and toxicology," recounts Peters.
Air Pollution: A Visible Issue
Among inner-city children, especially minority children, asthma is a prevalent problem in southern California. This situation inspired Peters and his colleagues to undertake the Children's Health Study, a 10-year prospective study involving 4,000 children in 12 different communities. The study, now in its sixth year, seeks to determine whether air pollution plays a role in asthma and other respiratory disorders. The study also addresses questions about the potential effects of pollution on lung function. "Since we are looking at growing children, one could presume that the growing lung might be more sensitive to effects of pollution," says Peters.
Another aspect of respiratory effects research is identifying how bioaerosols found in the home, such as dust mites, pollen, and spores, may compound problems associated with pollution. "One is struck by the fact that people worry a lot about air pollution but tend to overlook a large potential problem, namely, bioaerosols," says Edward Avol, a center member and an associate professor of occupational and environmental health at USC. To foster collaborative research on the issue, the SCEHSC held a workshop on bioaerosols in April 1997 that allowed center scientists to explore the topic with key investigators from other universities.
Shared environmental problems have also forged strong links between SCEHSC researchers and their counterparts in Mexico and China. In Mexico City, researchers are collaborating with colleagues at the National Institute of Respiratory Diseases and the National Institute of Public Health on gathering data comparable to that of the Children's Health Study. In Wuhan, China, the center is poised to begin a collaborative study with the Public Health and Anti-epidemic Station that will assess children's risks of developing asthma and other respiratory disorders as a result of air pollution. This research may also help genetic epidemiologists explore the variance in asthma rates between Los Angeles and Wuhan. "Asthma rates, despite the fact that [Wuhan is] a polluted city, seem to be much lower [there] than they are in the United States, and nobody knows quite why. Whether it's the way we diagnose asthma or whether it's genetic is unknown," says Peters.
Owing to the continuing eruption of Hawaii's Kilauea volcano, the largest active crater in the world, the Island of Hawaii suffers a corollary to Los Angeles's smog: a combination of volcanic ash and gases called "vog." Respiratory core members have also been working with researchers in Hawaii to determine the possible relationship between vog and asthma. "There are a lot of anecdotal reports from the community about increased asthma, increased respiratory infections, and increased health problems," says Avol, "but there's not a clear association between the volcanic emissions being present in the area and these respiratory problems." To assess the risk of such problems, center staff are providing training support for air sampling studies by the Hawaii Department of Health, to be followed by an assessment of acute and chronic respiratory health effects.
The Environment and Cancer
The SCEHSC adult cancer core focuses on the relationship between cancer and environmental factors, as well as on the gene-environment interactions that may modulate individual responses. "We define environment broadly in our program," says Ronald Ross, a professor of preventive medicine at the USC School of Medicine and director of the adult cancer research core. "To us, environment is everything that's not genetic. We define environment to include dietary factors, exogenous drug exposures, and estrogenic exposures such as oral contraceptives and exogenous hormones, along with the more traditional environmental contaminants."
Another gray day in L.A. Although improving, smog in southern California contributes to a variety of respiratory problems including asthma.
This approach is reflected in projects such as the research being performed by Giske Ursin, an assistant professor of preventive medicine at the USC School of Medicine. In the 1 September 1997 issue of Cancer Research, Ursin and her colleagues published preliminary results of a study suggesting that the risk of breast cancer associated with long-term (more than 4 years) oral contraceptive use may be up to six times higher in women with BRCA gene mutations than in other women.
In addition to hormonal links to cancer, the adult cancer core is also investigating the role of metabolism in cancer. For example, Ross explains that approximately 50-60% of all bladder cancer cases in the United States are linked to cigarette smoking. Tobacco smoke contains arylamines, carcinogenic compounds that are metabolized by enzymes such as N-acetyltransferase and glutathione S-transferase. Ross and his colleagues are investigating whether variations in the genes for these enzymes may explain disparate bladder cancer rates among different racial groups. "We are interested not only in understanding how individual variation of metabolism of smoking-related carcinogens might alter risk of bladder cancer, but [also in] further understanding how population differences in metabolism might explain these discrepancies," states Ross. "Exploring the genes that encode these kinds of enzymes is going to give us serious insights as to why we see extreme differences [in cancer rates] among different populations."
Gene-environment interactions are also investigated in the childhood cancer research core. Jonathan Buckley, a professor of preventive medicine at USC and core director, explains that one of the center's concerns is secondary cancers following treatment of a primary malignancy. There are indications that some children may have a genetic predisposition to develop cancer as a result of chemotherapy or radiation therapy. Other research in the childhood cancer core focuses on environmental contaminants such as polycyclic aromatic hydrocarbons and pesticide residues in household dusts. A recent study of children with brain tumors (See EHP 105[11]:1214-1220) conducted by Susan Preston-Martin, a professor of preventive medicine at the USC School of Medicine, and colleagues found an elevated risk associated with prenatal exposure to flea and tick pesticides, although pinpointing specific chemicals using data from the study was not possible.
![Volcano](niehsfigvolcano.JPG) |
Where the lava leaves the land. Lava from the Kilauea volcano reacts with seawater to create steam laden with hydrochloric acid, one of the volcanic emissions being studied by the SCEHSC and the Hawaii Department of Health.
Source: United States Geological Survey
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Exposure Assessment and Statistics
Typically, exposure assessment and statistics play supporting roles in epidemiologic research; however, at the SCEHSC, these fields boast separate research cores. "I think this center is unique insofar as exposure assessment constitutes its own research core," says John Froines, chair of environmental health sciences at the UCLA School of Public Health and director of the exposure assessment core. "An important goal is improving exposure assessment methodology, as well as developing better collaborative exchanges with epidemiologists on their investigations," he explains. At the center's outset, Froines and his colleagues were determined to address the need to improve exposure assessment, and founded the Southern California Exposure Assessment Group. This group comprises researchers from several institutions in southern California whose primary interest is exposure assessment. The group meets on an ongoing basis with epidemiologists to develop new research, Froines says. Backed by a grant from the National Institute for Occupational Safety and Health, Froines and his colleagues are currently tackling the issue of multiple chemical exposures. The potential health effects of the many chemicals and allergens present in paved road dust generated by traffic in Los Angeles are being studied by another exposure assessment core member, Glen Cass, a professor of environmental engineering at Caltech.
The SCEHSC statistics core confronts design and analysis issues that arise in epidemiologic research. "I see the field of genetic epidemiology as divided into two subdisciplines," says Duncan Thomas, a professor of biostatistics and genetic epidemiology at USC and director of the statistics core. "Some researchers are concerned with trying to discover genes and others are involved in trying to characterize them from a population perspective." One of the problems in characterization, Thomas explains, is that cohort studies require large numbers of study participants. A case-control study requires fewer people, but because it is subject to various potential biases, may not carry enough statistical weight to allow application to the population at large. A design that Thomas helped develop in the 1970s creates a happy medium. Nested case-control studies use cohorts to define the initial study population, identify cases within the cohort, and draw controls from the same cohort. The center is using this approach with various modifications to study issues such as estimating the effects of genes and environmental exposures within populations.
Playing with fire. The SCEHSC is working with Communities for a Better Environment on environmental justice issues such as the location of manufacturing facilities near playgrounds and schools.
Source: SCEHSC
Outreach and Education
Although the SCEHSC has existed for only two years, it has already established strong links to the community. "First, we are trying to understand the environmental health concerns of the community, as they relate to research we might conduct," explains Andrea Hricko, program director of the center. "Then we are helping community groups evaluate the science so that they are on solid footing when they publicly raise community health concerns." To meet this goal, the center offers technical assistance to grassroots community empowerment groups such as Communities for a Better Environment and Mothers of East Los Angeles. Assistance may be as simple as explaining how to use PubMed, the National Library of Medicine's scientific and medical citation search engine, or as technical as assessing soil and air samples for chromium contamination.
Blow by blow. Scientists from the USC School of Medicine are studying 12 communities in southern California to determine the health effects of air pollution on children's lung function.
Source: S. Dimas-Shull
Working with schoolchildren is an integral part of the center's outreach efforts, says Hricko. Several scientists in the center have helped to develop curricula for middle school science teachers or have hosted school field trips to center laboratories. "We think that having children become enthusiastic and knowledgeable about how scientists investigate environmental health issues is a critical part of what our center is doing," explains Hricko.
Peters adds that many of the SCEHSC's outreach efforts have evolved from community concerns about the possible links between environmental hazards and cancer, asthma, and other respiratory problems--all areas of expertise in the center. "The distinct advantage of the center," notes Peters, "is that different disciplines are brought together to work on complex issues that one investigator could never address alone."
Julia Barrett
The 1997 Presidential Distinguished Executive Rank Award has been awarded to NIEHS Director Kenneth Olden. In addition to a $20,000 cash prize, the award recognizes Olden as a top government executive. The award was presented on 5 May 1998 by Vice President Al Gore in Washington, DC.
![NIEHS director Dr. Olden](niehsfigolden.JPG)
NIEHS director Kenneth Olden
Source: NIEHS |
The Presidential Distinguished Executive Rank Award is presented in recognition of sustained extraordinary accomplishment by a federally employed executive. Nominees are reviewed annually by a board comprising representatives from business and industry, as well as private citizens. Final award recipients are approved by President Clinton.
The award recognizes Olden's successful and innovative leadership of the NIEHS. Olden has led the NIEHS and the National Toxicology Program as director since 1991. Once focused heavily on environmentally induced cancers, Olden widened the institute's range to include other disease endpoints in addition to cancer. In 1993, Olden created the NIEHS's first Office of Technology Transfer, which has since generated for the institute hundreds of thousands of dollars in research support and royalty income. Olden also embraced the concept of environmental justice, leading the Department of Health and Human Services to acknowledge not only particular socioeconomic and ethnic groups but also children and senior citizens as having special needs and risks in the face of the environmental effects of pollution. Finally, Olden's efforts have streamlined the NIEHS into a center dominated by research rather than by administration, and characterized by a spirit of cooperation and mutual respect.
Olden cites the launching of the Environmental Genome Project as his most memorable accomplishment of the past year. Of future goals Olden says, "The challenge I see . . . is obtaining an adequate budget to address the important public health issues related to the environment. To accomplish this objective, the institute needs a budget twice what it currently has."
Olden earned his bachelor's degree in biology from Knoxville College in Tennessee, his master's degree from the University of Michigan in Ann Arbor, and his doctoral degree from Temple University in Philadelphia, Pennsylvania. His 26-year career has included positions at the Howard University Comprehensive Cancer Center in Washington, DC, the National Cancer Institute in Bethesda, Maryland, and Harvard University Medical School in Boston, Massachusetts.
As a cell biologist and biochemist, Olden has led many discoveries into the properties of cell surface molecules and their possible roles in cancer. Olden was the first to demonstrate that organ-specific metastasis of malignant cells can be prevented by blocking the interaction between the glycoprotein fibronectin and the integrin receptor (today, Olden is considered a leading expert on the structure and function of fibronectin). In 1994, in recognition of his contributions to the field of health, Olden was elected to membership in the Institute of Medicine of the National Academy of Sciences.
After years of heated debate on the issue of precisely how electric and magnetic fields (EMFs) affect human health, scientific consensus may be hovering on the horizon. A working group has been charged with compiling a report for NIEHS director Kenneth Olden that appraises the strength of the scientific evidence of biological health effects due to exposure to 60-Hertz EMFs. On 15-24 June, the working group convened in Brooklyn Park, Minnesota, to continue a process that began with three earlier NIEHS science review symposia by reviewing and summarizing the reports produced by those symposia.
The first symposium was held 24-27 March 1997 in Durham, North Carolina, and covered theoretical mechanisms and in vitro research findings. The second symposium was held 12-14 January 1998 in San Antonio, Texas, and covered epidemiological research results. The final symposium was held 6-9 April 1998 in Phoenix, Arizona, and covered clinical and in vivo laboratory findings. Each of the three scientific review symposia examined the quality and reproducibility of the published research findings in its particular domain, with the goal of eventually evaluating whether the scientific evidence supports a causal relationship between EMF exposures and adverse human health effects.
The road to reaching a scientific consensus on this thorny issue, whose controversial nature arises from the disparities among the findings of EMF research projects, has been a long one. However, points out Christopher J. Portier, director of the hazard evaluation project for the NIEHS Electric and Magnetic Fields Research and Public Information Dissemination Program and coordinator of the science review working group, it is important to note that the June report is the report only of this particular working group; it is a consensus on the science as it stands now, rather than a final word on the matter.
The working group's final report is expected to log in at a hefty 400 pages. Each article reviewed includes an evaluative summary by the group. The report has been disseminated to approximately 500 scientists, and will be open for public comment for a period of 60 days prior to being published. After that point, the report and comments will serve as tools for Olden in preparing a congressionally mandated report responding to the question of whether or not EMF exposures affect human health.
Portier says, "The most interesting thing about what we're doing is that it's never been done before. It's a unique approach to addressing a potential human health hazard." The process that will culminate in the working group's report has examined the entire breadth of a massive body of literature in great depth, with each portion of that body being evaluated by the specialists most qualified to judge it.
The working group consisted of approximately 40 scientists representing the spectrum of currently held opinions on EMF effects. The group included scientists representing interests ranging from public activists to industry advocates to government investigators. But, Portier clarifies, while the report was requested by the NIEHS, "[This report] is not the NIEHS's opinion. This group is not speaking for the NIEHS, they are speaking to the NIEHS."
Last Update: June 18, 1998