Public Health, Fall 1997


A Toxic Legacy
Measuring mercury exposure in a coastal town, public health researchers are assessing the damage done by industry and building hope for a cleaner home.




In 1995, the Environmental Protection Agency (EPA) designated the LCP Chemicals plant in Brunswick, Georgia, as a Superfund site. While the EPA has its hands full cleaning up the toxic chemicals throughout the site, researchers at the Rol lins School of Public Health are tackling another job. Working with local health officials, they are assessing health concerns related to mercury exposure in the community.


by Sherry Baker

T"ourism brochures describe Georgia's coast near Brunswick as a paradise of glistening white beaches, turquoise waters, and blissful islands dotted with luxurious beach homes. But there is another side to this i dyllic picture. This beautiful coastline has long harbored a nasty little secret: for decades, industries contaminated hundreds of coastal acres with hazardous materials and exposed residents of the area, especially those who worked in the plants, to heal th-threatening toxins.

"Over the past 80 years, a lot of dirty industries located there, drawn by relatively cheap labor, lack of enforcement of regulations, access to raw materials, and good rail and sea access," says Howard Frumkin, chairman of the Department of Environmen tal and Occupational Health. "Glynn County, where Brunswick is located, has had around 20 major hazardous waste emitters."

The area's most infamous plant--beginning in 1956 as Allied Chemical and continuing as LCP Chemicals-Georgia in 1979--produced chlorine, caustic soda, hydrochloric acid, and hydrogen gas using the Solvay process. This chemical reaction, using mercury-b ased electrolytic cells, released large amounts of mercury into the surrounding 550 acres of marshland soil and waterways. Although scientists consider the maximum safe level of mercury to be 2 parts per million (PPM), they found mercury measuring 12,500 PPM in drainage canals on the site. While performing their jobs, hundreds of plant workers were exposed to the element, which can be toxic to nervous, renal, and reproductive systems.

In the mid 1990s, the state of Georgia revoked the facility's National Pollutant Discharge Elimination System and Air Quality permits and asked the Environmental Protection Agency (EPA) to research the location's contamination problem. The EPA soon dec lared the LCP Chemicals plant "one of the worst" toxic sites in the South and, possibly, the nation. Closed in 1994, it was designated a Superfund site the following year.

These days the facility is mostly gone. On the site of the once bustling plant is now a deserted field, wafted by ocean breezes. A sign declares in red: "Danger. This area closed to commercial and recreational activities...." The only workers who have come here in recent years resemble characters in a sci-fi movie--garbed in head-to-toe protective suits as they move high tech equipment through the site, cleaning up toxic chemicals.

A community issue



Howard Frumkin



This placid scene conceals unseen dangers, which researchers are trying to ferret out in an epidemiological study.

During the time the EPA moved in to decontaminate the area," Frumkin says, "it became clear that nobody was assessing the health concerns in the community related to possible mercury exposure."

To address those issues, Brooks Taylor, director of the Glynn County Health Department, invited Frumkin to a series of community meetings in 1995, which drew crowds of up to 500 people. Diverse groups in the area--including wealthy residents of seaside mansions and those in low socioeconomic groups, blacks and whites, environmental groups, fishermen, and chemical plant workers--joined together to discuss their concerns.

It became apparent that three groups might have been exposed to mercury from the LCP Chemicals site: fishermen and others who ate mercury tainted fish, residents who lived near the plant, and plant employees exposed to mercury at their workplace. Some people fell into more than one group.

"Workers were clearly at the highest risk," Frumkin says. "Dr. Taylor and I were soon talking about collaborative research and health assessments that would be responsive to this community concern."

The result was an epidemiological study, launched in early 1997, of former employees of the chemical plant. Funded by a grant from the National Institute of Environmental Health Sciences, it has proven to be the kind of project ideally suited to the Ro llins School of Public, Frumkin says. "This is an opportunity to do first-class research--to take a look at some unanswered questions about mercury, as well as to provide service. The project was initiated as a direct result of the community's concerns."

Frumkin, the principal investigator, was joined in the study by occupational physician Fred Gerr, behavioral scientist Richard Letz, neurologist Muhammad Siddiqui, and other scientists from the schools of Public Health and Medicine. These researchers w orked in collaboration with staff at the Glynn County Health Department.

The project also reflects the teaching mission of the school. Staffed with five student interns last summer, the project gave students hands-on field research experience in environmental health.

"This research made issues we study in class, like mercury toxicity, very real and concrete to me," says John Kim, who is pursuing a master's degree in health education.

Mary Margaret Driskell, a fourth-generation Emory student pursuing her MPH, agrees. "The project has piqued my interest in environmental health issues and in doing further research."

Finding the cohorts



Jesse Jones, a worker at the plant and president of the local union, helped convince other former workers to enroll in the study.

For the retrospective cohort study, the public health researchers worked with the Glynn County Health Department to recruit both former workers (who are mostly male and range in age from their 20s to over 65) and a comparison group with similar age, race, and gender composition that was not exposed to substances known to cause neurological, renal, and/or reproductive problems. Three different area employers--the Jekyll Island Authority, the Glynn County work force, and Interstate Paper--cooperated with the researchers to recruit volunteers for the control group. In all, about 300 volunteers enrolled in the study.

Recruiting former workers was challenging, notes Marsha Pierce, a Glynn County occupational health nurse specialist. When the LCP plant closed, it was a devastating economic blow that left some former workers embittered toward local and national govern ments. Many Brunswick community residents expressed mistrust toward researchers from the "big city" of Atlanta, according to Pierce, the local project coordinator.

"A lot of former workers have felt they are operating in the dark about their health exposures and risks," she says. "They've told me that things are happening to them instead of for them or with them. I worked hard in the recruiting process to establi sh a rapport with these people, so they would feel comfortable asking me any questions they had."

Jesse Jones, former president of the International Chemical Workers Union, local 716, and a former boiler operator at the LCP plant, was instrumental in helping convince former workers to enroll in the study.

"Every time I'd see someone who had worked at the plant, I'd say, 'A study is coming you need to take part in. We'll be calling you,'" Jones says. "I felt it was important for me to do this. When I worked at the plant, I tried to help the workers. I we nt to the company supervisors and told them people shouldn't work in these situations, with these chemical exposures. I tried to look out for their safety, but those people needed their jobs. Now I think they'll be better off knowing what's going on with their health."

The research questions



Marsha Pierce, an occupational nurse specialist with the local health department, and Rick Letz, a behavioral scientist, survey the site.



Study participants were given extensive tests, which analyzed everything from mercury levels to neuropsychological data.

Researchers designed the epidemiological study to replicate previous studies to enable them to confirm or refute earlier data that linked occupational mercury exposure with long-term neurological, renal, or r eproductive toxicity.

The study also looked at the excretion of mercury following challenge with the chelating agent DMSA (also known as succimer).

"Nobody really knows how to measure a person's mercury level. Blood or urine levels have typically been measured," says Frumkin. "On a group level, these measures reflect exposure. But on an individual level, both measures are highly variable and have limited value as biomarkers of exposure. If we can show that chelation challenge correlates well on a one-to-one basis with toxicity and/or what we think they were exposed to, then this study may reveal new information about whether excretion of mercury f ollowing challenge with DMSA is a useful biomarker of mercury exposure."

Another question the study hopes to answer: Is mercury toxicity associated with altered patterns of urinary porphyrin excretion?

While early findings have suggested that porphyrin profiles are a signature of mercury exposure, this hypothesis has not been confirmed. "If these findings are true, we will be the first group outside of the original investigators to replicate that res ult and confirm porphyrin metabolism as an effect of mercury exposure," says Frumkin. "That's important, because we know that a lot of metals are toxic to porphyrin metabolism. But that's not fully understood in the case of mercury."

Research subjects came to the health department in squads of seven, and spent about three and a half hours moving through a series of seven research stations, where tests, examinations, and interviews took place. "We asked about everything from how man y amalgam fillings are in their teeth to their fish consumption, so that we can factor in confounders," says Frumkin.

The researchers also queried the study participants about infertility problems, miscarriages and other reproductive issues. "However, in a study as small as ours--since reproductive abnormalities from mercury are pretty rare--we are unlikely to detect elevations," Frumkin says.

Quantitative neuropsychological and neurobehavioral data were collected by measuring subjects' responses to stimuli and manual dexterity tests. Computer administered tests, developed by Letz, recorded precisely timed memory reactions and hand/eye coord ination. Motor function exams included grip strength and balance tests. Nerve conduction and electrophysiologic testing helped assess neurological deficits.

Siddiqui, who conducted the neurological exams, notes that previous studies have shown that higher levels of mercury can cause cerebellar and postural tremors, as well as neuropathy. "Neurologically speaking, there are several ways mercury can affect t he functioning of the body," he says. "We also looked for the ability to think clearly, a good memory, the ability to be attentive, and complaints of excessive fatigue."

Each research subject provided two urine samples--one after a challenge with a dose of the chelating agent DMSA--and a blood sample. These samples then went to the Centers for Disease Control and Prevention (CDC) for analysis.

Calculating exposure

During the next year, the researchers will evaluate the data they've compiled and correlate those results with a reconstruction of workers' mercury exposure at the LCP plant.

"All occupational health studies succeed or fail based on how well they do exposure assessment, and we've really struggled with how to do it as well as we can. This study is an example of just about every method that can be used--from interviews to bio markers," Frumkin says. "We are collaborating with University of Georgia industrial hygienist Phil Williams to do an exposure reconstruction. He will take each individual's job history, deconstruct it, and plug it into a job exposure matrix, and we'll com e out with a best estimate of the person's mercury exposure."

Subtle markers



The community hopes that this study can create a sense of healing for those exposed to the hazards of this once-bustling site.

One of the interesting issues is that the old "mad as a hatter" type of mercury toxicity isn't really seen any more. "We are looking, instead, at relatively subtle neurobehavioral deficits like memory loss, s ubtle personality changes, things that are tough to pick up because they don't differ a lot from normal aging," says Frumkin.

"The only way to know if what is happening is the result of exposure is to do this kind of study--to look at a group exposed to mercury and see if the changes are happening faster in that group than they should be or are more severe than they should be ."

When the results of the tests are compiled, research subjects will be informed of those findings and directed to seek appropriate health care, if needed, through private physicians or the local health department. "People are naturally very worried abou t what these exposures to mercury may have done to them," says Frumkin. "We are mindful that part of our mission is to be able to answer their questions."

Brooks Taylor says the mercury study is only part of an ongoing effort to unravel the toxic legacy left on Georgia's coasts by polluting industries. "We are concerned about many other hazardous waste sites, although the LCP is the most prominent," he s ays. "We are working to interpret the risks to different community groups."

Taylor hopes to see his department's growing relationship with the school continue to expand. "It is certainly a benefit to us to interact with the Emory academicians," he says, "and I hope it is a benefit to them to work with our community and health department."

Jesse Jones says participating in the study has helped create a sense of healing within the Brunswick community. "Before the plant closed, I was fighting every day to hold on under those work conditions," he says. "I think this study can give people in formation and a guideline. If they have a problem due to mercury, maybe they will learn they need to change their way of living to take care of themselves. I think these researchers have already done the people down here a whole lot of good by showing the y care."


Fall 1997 Issue | At the Pinnacle | Ambassadors of Hope | A Toxic Legacy | Trials of Life
School Sampler | Alumni Sampler
WHSC | RSPH

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