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We are working to reduce . . .
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5,000 |
births per year with fetal alcohol syndrome |
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From more than 70 current projects, we have selected six to illustrate what we do. Ranging from basic research at the frontiers of science to projects with immediate practical application, they illustrate how the teaching, research, and service missions of the department serve the workplace, Washington state communities, and the larger community of environmental health researchers and professionals. One research team has helped explain how alcohol stunts development of the fetal brain, causing permanent disability. Another team has established the nation's most sensitive genetic fingerprinting technique to track down and eliminate causes of microbial food poisoning. Other researchers examine how environmental factors such as diet, smoking, and pesticide exposure - contribute to Parkinson's disease. Our partnership with employers, workers, and educators is represented by three projects: research into noise levels and hearing loss in construction and metalworking industries, remote sensing of airborne hazards, and a program to educate teenage workers about on-the-job safety risks. We hope you enjoy these snapshots of the Department of Environmental Health in action. Citations are in the appendix.
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| $40,000,000 | a year in disability compensation for hearing loss in Washington state | ||
| 1,000,000 | current cases of Parkinson's disease in the United States | ||
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The Occupational and Environmental Medicine program works with workers and health-care providers in Vietnam, Thailand, Costa Rica, Nicaragua, and Ecuador. This Vietnamese farmer uses a manual cultivator. |
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Fetal alcohol syndrome (FAS) the most common environmental cause of mental retardation is entirely preventable. The Department of Environmental Health recently published findings that help explain the mechanism by which alcohol stunts development of the fetal brain, causing permanent disabilities. Professor Lucio G. Costa, director of the department's Toxicology program, has spent more than a decade researching the effects of ethanol, a type of alcohol, on brain development. "Pioneering work on fetal alcohol syndrome," says Dr. Costa, "has been done here at UW by Dr. Ann Streissguth and her colleagues since the late 1970s. Yet, the mechanisms underlying the toxic effects of ethanol on the developing brain are still not known." Children with fetal alcohol syndrome have a range of central nervous system dysfunctions, including microencephaly (abnormal smallness of the brain) and mental retardation. Labels on alcohol bottles warn women not to drink during pregnancy. In the last three months before birth, a baby's brain undergoes its greatest growth. At this stage, alcohol can cause microencephaly in both rats and children. The condition appears to be irreversible. Dr. Costa's research seeks to understand potential mechanisms and determine whether therapeutic measures might prevent brain damage. The research has focused on astrocytes relatively large, star-shaped cells that surround neurons, the basic units of the nervous system. Astrocytes and other glial (supporting) cells are thought to have important metabolic functions. Work by Dr. Marina Guizzetti, a postdoctoral fellow in Dr. Costa's laboratory, has shown that low levels of alcohol (the equivalent of 0.06 to 0.2% in blood - not too different from the 0.08% limit for driving) can inhibit the proliferation of astroglial cells. This may contribute to some of the toxic effects, such as microencephaly, seen in FAS. One of Dr. Costa's graduate students, Michelle Catlin, recently published her doctoral dissertation on the effects of ethanol on astroglia. She found that low levels of ethanol inhibited the effect of calcium in these cells. As calcium plays important roles in cell functions, these results may be relevant to understanding FAS. She studied the calcium uptake of cells using a special tool, a confocal microscope that was provided with support from the department's Center for Ecogenetics and Environmental Health grant from the National Institute of Environmental Health Sciences (NIEHS).
The
center UW is one of 20 NIEHS centers doing interdisciplinary research in environmental health sciences. Dr. Costa is director of the UW center's neurotoxicology research core, focusing on environmental causes of chronic neurological diseases, such as Parkinson's disease, Alzheimer's disease, amylotrophic lateral sclerosis (ALS), fetal alcohol syndrome, and mechanisms of cell death. Dr. Costa coordinates the work of researchers from the UW departments of Environmental Health, Medical Genetics, Epidemiology, and Pathology. He is also studying another cause of mental retardation, the inability to metabolize phenylalanine. This may lead to a syndrome known as maternal phenylketonuria (mPKU). His research on maternal PKU-related mental retardation also comes under the NIEHS grant. This interest stems from the observation that the effects seen in children with mPKU and FAS (microencephaly and mental retardation) are very similar. Dr. Costa's research is funded partly by the NIEHS and the National Institute on Alcohol Abuse and Alcoholism (NIAAA). |
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Dr. Mansour Samadpour, a microbiologist and food scientist, has established a nationally prominent molecular epidemiology laboratory at the UW. His work allows for fast identification of food- and water-borne illnesses. His work, and the groundbreaking epidemiology by the Seattle-King County Department of Public Health that it supports, are among the reasons that sources of environmental diseases are often identified first in the King County area. For example, an outbreak of Salmonella in June 1999 was reported first in King County, though cases were subsequently identified in 15 other states. The strain was identified as Salmonella, Muenchen variety, and the King County epidemiologist, with assistance from Dr. Samadpour's laboratory, began searching for the source. A unique genetic pattern or fingerprint allows epidemiologists to pursue only those cases of food poisoning caused by an identical strain of bacteria. Fingerprinting can definitively identify the source or, as Dr. Samadpour puts it, "weed out the background." Within a week after the first patient clusters were identified in June, King County epidemiologists identified the source as unpasteurized orange juice that was used in fruit smoothies at a restaurant chain. The juice company issued a voluntary recall.
Proactive epidemiology Previous epidemiological methods could take months to pinpoint a source. "They end up doing a postmortem study and writing scholarly papers," Dr. Samadpour said. He prefers to use epidemiology to identify outbreaks in the early stages what he calls "proactive epidemiology." Identifying the cause based on the first few cases is "much harder and more time consuming" than waiting for patterns to unfold, he said. "We want to push epidemiology in a direction it hasn't gone before." The department and the county worked together during the 1996 out-break of Escherichia coli that was traced to unpasteurized apple juice. Sixty-six cases were identified and one person died, yet the toll could have been higher. The relatively quick identification allowed the juice company to pull suspect products off store shelves within a week. Dr.
Samadpour's lab also works with air and water pollution. For example,
King County officials feared that fecal bacteria contaminating a beach
on Lake Washington might have been from a nearby trunk sewer line. Dr.
Samadpour was able to rule out the sewer line by linking the contamination
to ducks and geese. His technique, called microrestriction analysis, delivers a more exacting fingerprint of bacterial strains than the computerized analysis called PFGE (pulsed field gel electrophoresis) used by most public health departments.
Fingerprints The fingerprints show variation among bacterial strains in the lengths of DNA fragments cut by certain enzymes. Restriction enzymes recognize specific nucleotide sequences; each enzyme cuts the DNA at a specific recognition site. After bacteria are isolated from a patient's clinical samples, Dr. Samadpour's laboratory extracts the bacterial DNA and enzymatically cuts it into fragments, which are then resolved on the basis of their sizes to generate genetic fingerprints. The presence or absence of shared fragments shows the bacteria's relatedness: bacteria with identical restriction fragment patterns most likely come from the same source. Dr. Samadpour's technique builds on methods established by the Centers for Disease Control and Prevention (CDC). His enhancement has become so widely known that, in 1998, he was brought in to fingerprint the cause of an E. coli outbreak at a suburban Atlanta water park - literally in the CDC's back yard.
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People with Parkinson's disease have low levels of dopamine, a neurotransmitter that helps control muscle coordination. Dopamine usually inhibits the transmission of nerve signals; without it, nerve pathways can overload. These excess signals can overexcite the muscles, causing them to stiffen and lock, as might a computer attempting to run too many programs at once. The degradation of dopamine-releasing nerve cells is a normal and inevitable part of aging, Dr. Checkoway said. "We all lose some dopamine production. People move more slowly as they get older and that is one of the reasons." There is also some evidence that environment may be a factor. Rather surprisingly, some cigarette smokers are significantly less likely to develop Parkinson's disease than nonsmokers. Recent research in the department's Center for Ecogenetics and Environmental Health helps clarify the connection between Parkinson's disease and smoking, as discussed below. Dr. Checkoway is also lead investigator on a Parkinson's study funded under a Superfund Basic Research Program grant from the National Institute of Environmental Health Sciences (NIEHS).
Genetic Factors His study found that smoking only protects people with a gene variation that puts them at higher than average risk for contracting Parkinson's disease. Among people who do not have this variation, smoking increases the chance of getting Parkinson's disease. The
gene in question is MAO-B, which produces an enzyme that destroys dopamine.
People who are at higher risk for Parkinson's have a form of MAO-B (the
"G" variation)
that may break dopamine down too quickly. Smoking appears to slow the
action of the MAO-B enzyme, helping maintain necessary dopamine supplies.
A drug (selegiline) partly mimics smoking's effect on Parkinson's by inhibiting
the MAO-B enzyme. Dr. Checkoway is also researching connections between diet and Parkinson's disease. His team studied the diets of newly diagnosed Parkinson's patients at Group Health Cooperative and compared them with similar Group Health members who had no diagnosed neurodegenerative diseases. Researchers found an increased risk of Parkinson's disease among people who ate more animal fat, but there was no apparent protection from diets high in antioxidants, such as Vitamins A and C. Pesticides have been implicated in Parkinson's disease. Laboratory experiments suggest that pesticides could damage the mitochondria (principal energy sources of the cells). Epidemiological research on this topic is being conducted through the Pacific Northwest Agricultural Safety and Health Center (PNASH).
Agricultural Workers Drs. Checkoway and Matt Keifer, along with Dr. Kent Anger from Oregon Health Sciences University and Larry Engel, a recent PhD graduate in Epidemiology, completed a study of about 300 elderly orchardists from the Wenatchee area of Washington state. Participants filled out an extensive questionnaire that described their use of pesticides and took neurological examinations, and memory and cognition tests. The research team looked for early Parkinson's symptoms (parkinsonism). Findings could help predict neurologic disease risk in pesticide-exposed workers. The results showed more frequent symptoms of parkinsonism in orchardists with the longest duration of exposures to pesticides. However, further research will be necessary to identify specific pesticides that may contribute to these symptoms.
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Hannah is prepared to handle such situations. She learned to speak up for herself during classroom exercises that are part of a curriculum developed at the UW under a Washington state program called School to Work. One lesson from this curriculum turns familiarization with child labor rules into a competitive game. Another lesson, the CLEVER game, encourages students to brainstorm alternative solutions for managing workplace hazards. Although the curriculum includes fun and games, the teen safety problem is anything but trivial. Consider these examples:
National statistics show that teens have a higher occupational injury rate per hour worked than adults. Each year in the United States, about 70 teens die from work injuries and more than 200,000 are injured on the job, according to the National Institute for Occupational Safety and Health (NIOSH).
To reduce the number of injuries, the Department of Environmental Health trains classroom teachers in a health and safety curriculum. One educator who took the course at the Washington Vocational Association conference said she had been "looking for an in-service (teacher training) like this for a long time." The outreach program is run by the department's Health & Environmental Resources for Educators (HERE@UW). Oversight is provided by a steering committee chaired by the state Department of Labor and Industries (L&I) and created by the Governor's Task Force on School to Work. Through this program, university researchers and staff, public schools, businesses, government agencies, and community organizations work together to educate teens about their legal rights and potential workplace hazards. The mission is to see that all young workers in Washington have a safe and healthful work environment. The program is funded jointly by the state Medical Aid and Accident Funds, the National Institute of Environmental Health Sciences, and the National Institute for Occupational Safety and Health. The program has trained more than 300 educators to present a four-day occupational safety and health curriculum for middle and high school classrooms, using a video, wallet card reminders, posters, brochures, and Internet links.
Teacher training Teachers are trained through UW extension courses, professional conference presentations, and exhibits. Instructors include faculty and researchers from the department's Center for Ecogenetics and Environmental Health, and representatives from L&I. Newsletters provide follow-up for the teachers. Susie Shields, career specialist at Kentridge High School and a Parent and Teacher Association (PTA) leader, has taught the four-day curriculum in several classrooms. "The curriculum is extremely useful and should be required for all teens," she said. "My students all of a sudden felt empowered because they knew their rights and knew what to do if a problem at work occurred."
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Compensation claims The number of claims for occupational hearing loss in Washington state has increased tenfold in the past decade and the cost of compensation has risen even more sharply, according to research by Dr. William Daniell of the Occupational and Environmental Medicine program. By 1996, the costs of disability compensation reached almost $40 million a year. Dr.
Daniell is helping the state Department
of Labor and Industries (L&I) find
ways to prevent hearing disabilities and control costs. One of Dr. Daniell's
graduate students, Sue Swan, worked with L&I to evaluate how well
metal-casting foundries protected their workers' hearing. Swan measured noise exposure and compliance with regulations in ten foundries. She found that all of the work sites had substantial deficiencies in their hearing conservation programs. Although all of the employers provided hearing protection and minimal annual training, none provided training in languages other than English or special retraining for employees with a documented hearing loss. She
and Dr. Daniell presented their findings to L&I. Although Swan has
graduated, she and Dr. Daniell continue to work with the state to evaluate
inspection methods and has received federal funds to evaluate noise exposure
and hearing conservation at representative work sites in nine other Washington
state industries. Rick Neitzel, a research industrial hygienist with the Field Research and Consultation Group, studied construction workers for his master's thesis. From June to December 1997, he monitored 133 carpenters, laborers, ironworkers, and operating engineers. An activity log accompanied each of the 338 samples collected with noise dosimeterssmall microphones connected to sound-measuring devices. Neitzel found that 13% of the eight-hour averages exceeded the federal standard of 90 decibels and 40% exceeded the more protective state standard of 85 decibels. Higher exposures across all trades could be predicted based on the stage of construction and on the tools being used.
Electricians Kyle Ren, a 1999 master's graduate, studied electricians in the construction industry. Working with Dr. Noah Seixas, Ren wired the workers with dosimeters. He collected 174 samples over four months and had workers fill out an activity log for each sample. Not surprisingly, pneumatic power tools were noisiest (88.89 decibels). Old-fashioned, hand-held hammers ranked third on the list, after powder-actuated tools. Ren found that younger electricians had the highest exposures, which he attributed to their work assignments and the length of time they took to complete a task. Nearly a quarter of the 174 eight-hour samples exceeded the state's limit of 85 decibels. The electricians knew their environment was noisy, yet they used hearing protection devices less than 15% of the time. The NIOSH-funded Education and Research Center, or ERC (the Northwest Center for Occupational Health and Safety), provides stipends for industrial hygiene students, as well as occupational medicine and occupational health nursing students. Swan and Ren were partially supported by ERC funds. Neitzel worked with faculty researchers Noah Seixas, Janice Camp, and Mike Yost, and has presented his findings to a number of trade and professional organizations. Dr. Daniell is also collaborating with a labor-management safety and health council on a federally funded demonstration project to establish a hearing conservation program for the construction industry. |
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A faster and more sensitive technique has been developed and refined by Dr. Michael Yost and his team at the Optical Remote Sensing (ORS) lab. Using an analytical instrument called an Open Path Fourier Transform Infrared spectrometer, or OP-FTIR, they can take a quick reading of the air in a work site, analyze its chemical composition, and determine the concentration of pollutants. Their instrument is portable enough to be taken to work sites. It measures chemicals by shining an invisible infrared beam through the air and detecting changes in the intensity and color of the light. Just as visible light can be sorted into a spectrum of wavelengths, infrared light can be sorted into a spectrum corresponding to different temperatures or energy levels. The infrared light bounces off a reflector and is gathered by a telescope fitted with a special detector that is cooled by liquid nitrogen to -320° F. Because infrared light is thermal energy, the detector provides extraordinary sensitivity. A given chemical will absorb energy only at particular wavelengths, producing a unique pattern or fingerprint for each compound. The instrument can qualitatively identify contaminants in the air and quantitatively measure their concentration, nearly instantaneously. The method can identify components in complex mixtures with detection limits down to a few parts per billion. Because it allows remote sampling, the instrument can measure contaminants several hundred meters away, without requiring workers to enter potentially hazardous areas.
Risk evaluation OP-FTIR technology was used at the Hanford Nuclear Reservation as part of the Consortium for Risk Evaluation with Stakeholder Participation (CRESP) project. Investigators Dr. Ram Hashmonay and PhD student Robert Crampton established baseline OP-FTIR measurements at the Hanford "tank farms" (which contain 54 million gallons of high-level, radioactive waste). In February and March 1999, they monitored tanks during waste pumping operations. Preliminary analysis identified release of hydrocarbons and nitrous oxide, and the team plans to follow up using nitrous dioxide as a tracer for hydrocarbon compounds.
Worker
Exposures OP-FTIR technology was also used to monitor worker exposures at a boat-building company in Skagit County, where resins released a mixture of styrene and other volatile chemicals into the air. Some worker exposures were brief but intense, and couldn't be measured by conventional methods. Another recent project involves Noel Fitzgerald, an undergraduate student in the chemistry honors program at UW and a firefighter. His research topic is to adapt OP-FTIR sensing methods to identify and measure noxious vapors at fire scenes.
Other uses Dr. Yost sees future applications in pinpointing emission sources and hot spots. Instead of measuring gases along a single path, he and his colleagues can set up an array of reflectors and feed data into a computer program that can map pollutant concentrations spatially. These maps can pinpoint sources, for example, in an industrial area with several potential emitters. Mapping can also determine impacts on neighborhoods near refineries, industrial sites, dairy farms, or other emission sources. The US Department of Agriculture and the Environmental Protection Agency have expressed interest. Dr. Hashmonay, a postdoctoral researcher with the department for the past three years, is moving to a consulting firm in North Carolina and will "carry the torch" of OP-FTIR research to those agencies. "This is a tool that can measure a wide range of occupational and environmental exposures," Dr. Yost said. "Our role now is to improve the technology and make it easier to use and more sensitive."
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Mansour
Samadpour started researching enteric pathogens in 1977
as a college junior recently arrived from Iran. His research
into causes of traveler's diarrhea interested him so much
that he abandoned plans for medical school and majored
in microbiology instead.
Professor
After
school, you'll find Hannah in a restaurant kitchen, earning college money
and learning lifetime work habits. But what if she gets hurt on the job?
What if she burns herself or lifts something too heavy? What if her boss
asks her to do something that seems unsafe?
Construction
sites and metal foundries are inherently noisy places, yet many workers
fail to use hearing protection consistently. Researchers in two departmental
programs - Occupational and Environmental Medicine, and Industrial Hygiene
and Safetyn - are studying the nature of noise exposures, patterns of
hearing loss, costs to industry, and barriers to more widespread use of
hearing protection.
In
many occupations, workers are exposed to complex mixtures of volatile
compounds, or to rapidly changing air concentrations. Traditional sampling
techniques for workplace air can take weeks to analyze and, even then,
often can't capture the peak levels of exposure.
