Scientists Conduct Little Research on Air Toxics' Effects on Texas Gulf Coast
Jan. 18—In 1992, Connie Walding of Baytown discovered she had breast cancer. In 1996, her husband, Scott, got throat cancer. Last year, her dog died from cancer of the lymphatic system.
A neighbor tallied 14 more cancer cases over several years in humans, dogs and horses living on a two-mile stretch of FM 1942 just down the road from a massive petrochemical complex.
Fearing toxic air emissions were making them sick, the residents persuaded state health officials to investigate. A state cancer epidemiologist compared the cases with state cancer rates. The result came as a surprise to many: Cancer in Baytown was within the normal range.
"You wonder, 'Is this biased? Is this accurate?' " said Baytown resident Shirley Ulrich. "Why aren't expectations for the state higher?"
Like Ulrich, many people believe hazardous air pollutants on the Texas Gulf coast are a deadly public health problem. A Houston Chronicle investigation of air quality last summer found that people living near industrial plants along the Houston Ship Channel are being exposed to levels of airborne carcinogens that if inhaled over a lifetime would increase chances of getting cancer, according to federal risk estimates.
Last week, the Texas Commission on Environmental Quality, citing older data, said that levels of benzene and 1,3-butadiene were high enough in some Ship Channel neighborhoods and at the Lynchburg Ferry that an additional 29 to 199 people in 1 million could get cancer if the concentrations were inhaled continuously over 70 years.
Yet proof of a link between cancer and air pollution remains elusive.
Part of the reason is that research exploring the link between air toxics and cancer in Houston, a city famous for cancer treatment and bad air, is nearly nonexistent.
Establishing the impact of hazardous air pollutants on communities is scientifically difficult — some might say impossible. But elsewhere around the world, researchers are struggling to know more so regulators can set healthy limits. Johns Hopkins University, Harvard University, the University of California and others dominate the field, spending tens of millions of dollars in federal grants.
Some believe a pro-industry bias here essentially blocks research; others blame Houston's information gap on a deeply imbedded indifference to the problem.
"Houston is a petrochemical town," said Maria Morandi, a scientist at the University of Texas School of Public Health in Houston who studies where and how people are exposed to hazardous air pollutants. "You see the positive aspects of the industry, which are many, so the focus is on that, and not so much on the negative aspects of the industry.
"Some of us are doing studies," she added, "but when you compare the number and size of studies we're doing with what other states are doing, we are really, really a minor player in this area."
Fifteen years ago, amendments to the U.S. Clean Air Act created a federally funded air toxics research center in Houston. It was named for the late congressman Mickey Leland to honor his work for the environment, and it had a congressional mandate to study cancer and other health problems related to air pollution.
Just as high cancer incidence on the Texas Gulf Coast had helped make UT's M.D. Anderson Cancer Center a world leader in cancer treatment, Houston's pollution from automobiles and the petrochemical industry would make the area fertile ground for air toxics researchers. The Mickey Leland National Urban Air Toxics Research Center at the UT School of Public Health — funded by the U.S. Environmental Protection Agency with contributions from industry — was celebrated as a boon to Houston's research agenda.
It was going to ask the tough questions.
But early on, the center quietly shifted its focus away from cancer and away from Houston.
Even though few, if any, epidemiological studies looking at cancer and pollution in Houston have been done since the 1970s — and despite a huge population with on-the-job exposure to toxics — the center's leaders decided to leave cancer research to better-funded agencies such as the National Cancer Institute and the U.S. Centers for Disease Control and Prevention. The Leland Center has a modest $1 million to give away annually.
"The Mickey Leland Center has never done what I think it was supposed to do," said attorney Jim Blackburn, who teaches environmental law at Rice University. "It seems to have always been inordinately concerned with industrial points of view.
"You have a fabulous laboratory in Houston. There's no question there's chemical exposure of the general population of this town. That's why I was always amazed when the Mickey Leland Center started out not studying Houston air pollution. They've been headed in the wrong direction ever since."
Carlos Antonio Rios / Chronicle Chronicle study volunteer Debra Prophet of Baytown sits on her back porch facing the Exxon Mobil plant and comforts her grandson Alonzo Mosley, 3. They both have asthma, and on bad, smelly days, Alonzo has to stop playing in the back yard and get on his breathing machine.
The center instead concentrated on developing tools to measure an individual's exposure to pollutants, an essential component in linking toxics with illness. It has also paid for studies and organized scientific meetings looking at the role of pollution in exacerbating asthma. Those projects are well-regarded in the field.
"It was an appropriate decision," said Dr. Patricia Buffler, a molecular epidemiologist at the University of California at Berkeley who was the Leland Center's first board chairwoman and led the center through its early years of planning. "In terms of outdoor air pollution, the greatest impact is on noncancer (health effects) like asthma."
Ray Campion, the center's first full-time director, said the center paid for studies in New York, Los Angeles and Chicago because applications didn't pour in from local researchers. In a decade and a half, the Leland Center has given out $7 million in grants, resulting in roughly two dozen scientific papers published in peer-reviewed journals. It also is funding Morandi's work.
By comparison, the Health Effects Institute in Boston, on which the Leland Center was modeled, gives away $5 million to $7 million every year and has published more than 220 research papers in 25 years. That institute, which is funded in equal parts by the federal government and the automobile industry, pays for theoretical, epidemiological, human exposure, animal and lab studies.
Most of the Leland Center-funded papers focus on cities other than Houston.
Director Craig Beskid said that is because the center's board of directors is "focused nationally," though one could argue that a Houston-based study published in a peer-reviewed scientific journal would have national impact. Beskid said he is working on an initiative to jump-start Houston-based research.
"I don't think the results have been particularly spectacular, but that's because funding has not been particularly strong from government or industry," said George Smith, who heads the board of directors for the Galveston-Houston Association for Smog Prevention. "I know these studies are expensive and they're difficult and they take time to come to fruition. But I'd say the whole thing has been less than a roaring success."
Lovell Jones, director of the Center for Research on Minority Health at M.D. Anderson, is skeptical of the Leland Center's explanation for its research focus. Jones' center targets health disparity issues.
"What we say to people around the country is, 'Houston is a model center to look at," " he said. The Leland Center, he added, "could have easily invited people down here. That's what we've done here."
Others charge that local research lags because industry dominates decisions on what gets studied. The companies contribute just 10 to 15 percent of the Leland Center's annual budget, but the people leading the center's board of directors and its scientific advisory panel, which set the research agenda, often are from industry.
Board members are appointed by the U.S. president, House speaker and Senate majority leader, as stipulated by the law that created the center. The board chairwoman is Josephine Cooper, a top lobbyist for Toyota Motor North America (considered one of the most "green" of automobile manufacturers). The chairman of the science panel is James Collins, director of epidemiology at Dow Chemical Co., which has its largest site in Freeport. Other board members have rotated through jobs in academia, federal work and private industry.
In contrast, the Health Effects Institute's board members are public figures in science and policy; the board chairman is the president of Colorado College. Though board members must be approved by the EPA and industry sponsors, they cannot be from the EPA or industry.
The perception of industry bias at the Leland Center is important, said Jones, even if no one is actively blocking air toxics research. If nothing is done to counter that perception, he said, "you essentially are blocking it."
Even if Houston were the epicenter of air toxics research, scientists would still be a long way from understanding the impact of industry on health, particularly cancer. Some doubt there will ever be a link as clear-cut as the relationship between cigarettes and lung cancer.
"I don't think we'll ever be able to say, 'Chemicals along the Ship Channel cause cancer,' " said Jonathan Ward, director of environmental toxicology at the University of Texas Medical Branch at Galveston. "The best we can do is understand the exposure... understand health outcomes... and then make up our minds (on the risk) and build our regulations on that."
The biggest obstacle is the nature of cancer itself. Cancer takes a long time to develop — 10 to 30 years for most types, scientists say — making it hard to pinpoint a single cause. In addition, the nation's second-leading cause of death comes in many forms and may be caused by factors such as tobacco use, diet, genetics and lack of exercise. Age, race and gender also play important roles.
"You have higher emissions and you also have higher cancer rates (in some locations) than nationally, but nothing that ties the two together — and nothing that excludes smoking," said Ward.
Chemicals such as benzene and 1,3-butadiene have been linked in studies to leukemia in lab animals and petrochemical plant workers, but their impact in the community is couched in uncertainty. The EPA has estimated that lifetime exposure to benzene levels of 4 parts per billion (roughly four molecules of benzene for every billion molecules of air) would cause, at most, 100 additional cases of leukemia for every 1 million people.
But they can't put human beings in a chamber with toxic chemicals to measure their effects.
"The health science associated with these individual pollutants is very, very complex, and it's very much in its infancy," said Sally Shaver, director of the emissions standards division of the EPA. "There is no doctor in America that can tell you what caused your breast cancer, what caused your lung cancer. They won't tell you why your child's IQ is five points lower than another child's."
The U.S. occupational standard for benzene is 1 part per million, or 1,000 parts per billion. In local communities, the worst annual average benzene levels measured are well below that, ranging from 0.94 part per billion in La Porte to 2.64 parts per billion at the Lynchburg Ferry in Baytown, according to averages from state monitors in 2003. Those levels may translate into cancer cases, and additional air toxics may compound the risk, but scientists have not measured the effect in communities.
At the Chronicle's request, epidemiologists at the state cancer registry analyzed 1995-2001 cancer occurrence data from nine ZIP codes with high levels of hazardous air pollutants. These include 77012 and 77017 in Houston and certain ZIP codes in Port Neches, Port Arthur, Clute, Freeport, Groves and Baytown. The data came from hospitals and pathology labs where cancer is diagnosed.
In Freeport, state investigators saw a greater-than-expected occurrence of lung cancer in men (68 cases observed vs. 47.83 expected) and an elevation of non-Hodgkin's lymphoma in women (18 cases observed vs. 7.79 expected).
In Freeport men, cigarette smoke obscured other lung cancer causes, as is often the case.
"We were not able to separate out the possible effects of smoking in the population under study," the state's report said. According to the American Cancer Society, smoking accounts for 87 percent of all lung cancer.
The elevated rate of non-Hodgkin's lymphoma in women warrants further investigation, the state says. Because non-Hodgkin's lymphoma is more common in men, particularly those who work with pesticides or solvents, the state cancer registry wants to know why there are unusually high numbers among women.
Tobacco smoke is another source of air toxics, so women who smoke, or live with men who smoke, would be at greater risk of developing disease. Texas epidemiologists plan to reanalyze non-Hodgkin's lymphoma in subsequent years as more data accumulate. A continued elevation or increase could mean there's an ongoing exposure to something that causes cancer.
In all the other areas studied, lung cancer, leukemia, brain tumors and other cancers occurred within the expected ranges.
In Baytown, where the Waldings' cancer is in remission and where residents documented more than a dozen cancer cases in a small area, the cancer types were all different — cancer resulting from exposure to a particular toxic would be expected to be one type. In addition, most of the cases occurred in people over the age of 65, the age when cancer most commonly occurs.
Analyzing cancer occurrence by ZIP code is too crude a measure to definitively rule out or confirm a threat, experts say.
For example, within a ZIP code, some people may be living closer to an emissions source than others. Some people may have lived in a location for too short of a time to develop cancer; other longtime residents may move away and develop cancer later.
So investigators are approaching the question from different directions. For example, Ward is looking at biological markers of 1,3-butadiene — genetic mutations in white blood cells caused by the chemical in some people. He's trying to determine if current levels of butadiene cause DNA mutations, because mutations lead to uncontrolled cell growth, which is what causes cancer.
But not everyone who is exposed develops mutations, and not everyone with mutations gets cancer, he said.
A UT School of Public Health project is using personal monitors to measure an individual's pollution exposure and correlating the findings to indoor and outdoor measurements. The idea is to find out whether a person inhales more benzene filling up a gas tank or living across the fence from a synthetic rubber plant, and then work to reduce those exposures.
One early finding is that many people encounter higher concentrations of benzene indoors, especially in homes with attached garages and cars parked very close on driveways and under carports.
Investigations in other locations may offer insight into toxic air dangers.
A recent study in China showed damage to blood cells in people exposed to levels of benzene lower than the U.S. occupational standard of 1 part per million. In the study, published in December in the journal Science, scientists compared 250 benzene-exposed shoe factory workers with 140 unexposed people. Individual benzene exposure was monitored for up to 16 months with urine samples collected at the end of a person's work shift.
The study found that blood cell production declined and all types of white blood cells were decreased in workers exposed to less than 1 part per million benzene compared with people not exposed to the chemical. Researchers believe genetics play a role in activating or detoxifying benzene, making exposure more dangerous for certain people.
Dr. David Christiani, a professor of occupational medicine and epidemiology at the Harvard School of Public Health in Boston, is leading a five-year, $2.2 million case-control study looking at cancer in children and young adults who live in the southern Taiwan city of Kaohsiung.
Kaohsiung has five large petrochemical plants within the city limits, adjacent to heavily populated areas. Case-control studies can't prove, but may suggest, some factor is responsible for the illness.
For the study, Christiani and his colleagues recruited people under 30 who had newly diagnosed leukemia and brain cancer. They were randomly matched with young people in the community who resembled them in age but didn't have cancer. Researchers then analyzed the differences between them — where they live, its distance from the plant and the characteristics of their parents.
Such a study is easier in Taiwan because people there don't move as often as Americans. The average American relocates every three years, Christiani said. In contrast, most of the families in his Taiwan study have had no more than two or three addresses in their lifetimes.
In addition, Taiwan has higher levels of emissions than those found in the United States, so it may be easier to observe cause-and-effect relationships. Taiwan's rapid cancer reporting system gave Christiani quick access to newly diagnosed patients, so he could interview them before they became too ill. In the United States, researchers using cancer registries generally wait two years for information about cancer patients.
"What I can tell you is, to date, preliminary results show that proximity is associated with childhood leukemia, but not brain cancer," Christiani said, adding that traffic emissions near the plant may also play a role. "I think we're starting to find some things. There's a lot we're trying to account for."
Chronicle reporter Dina Cappiello contributed to this story.
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