Federal researchers have a long way to go to collect the data and recruit the subjects necessary for what is billed as the largest, most significant study of human health effects ever attempted following an oil spill.
Dale Sandler, chief epidemiologist for the National Institutes of Health, said her agency has, after eight months of work, secured the participation of about 2,800 people who worked in various cleanup and response roles after the Deepwater Horizon rig exploded in April 2010, causing the largest crude oil spill in American history.
That’s 5 percent of Sandler’s goal of attracting 55,000 participants, with the potential to track the health status of more than 20,000 of those people for a decade or longer.
Using records from training programs for cleanup workers, employment records from BP and their cleanup contractors, the Vessels of Opportunity program and other sources, researchers compiled a target list of 155,000 people. They began sending out letters and making telephone calls in February.
But there are complicating factors, Sandler said, from general distrust and “research fatigue” among the coastal community to outdated contact information and civil attorneys advising their clients not to participate.
Sandler recently concluded a four-day tour of the Louisiana-Mississippi coastline trying to drum up attention for her effort. Besides community meetings and engaging local public health authorities, she is asking anyone who did cleanup work or just took the safety training, without actually working, to volunteer for the study.
“We want them to call us, and we’ll keep trying to get to them,” she said. Separate studies, supported by NIH grants, are intended to assess health effects among Gulf Coast residents who did not necessarily have direct exposure to the oil or dispersant through cleanup jobs.
Sandler’s study targets residents of Louisiana, Mississippi, Alabama and Florida, although Sandler recently extended eligibility to residents in eastern Texas. Residents interested in participating can call 855.NIH.GULF (855.644.4853) toll-free. Details are available online at www.nihgulfstudy.org.
Seeking scientific evidence
Fear of human health effects from the spill — driven in part by BP’s use of more than 1 million gallons of the chemical dispersant Corexit at unprecedented depths under water — has angered concerned fishers and other coastal residents. Current circumstances feature anecdotal evidence of sick workers and Gulf Coast residents complaining of maladies — respiratory problems, in particular — that generally can be associated with organic compounds found in crude oil. Some scientists and physicians have weighed in with tests on samples of seafood, human blood and Gulf Coast soil that show elevated levels of some of the same toxins. But there has been a dearth of scientific evidence directly connecting illnesses to the oil or the dispersants.
Government officials have been unwilling to accept a direct causal effect but also unable to disprove it. President Barack Obama’s Oil Spill Commission said it was disturbed by the anecdotal evidence, but it left the issue to others in the January report on its investigation of the spill and its aftermath.
Sandler said she is working to design a study that draws the strongest possible corollaries, even if absolute causation is not possible to determine.
“I want to be able to say that workers who did this particular job are more likely to suffer this particular consequence,” she said.
Participants begin with a detailed questionnaire about their post-spill experience, their job history and their health history, among other details. For example, benzene, a component of crude oil, is a known carcinogen. But Sandler noted that the most common source of benzene exposure is smoking tobacco and pumping gas.
“We have to know what other factors come into play,” she said.
In-home visits follow, including a battery of tests to establish health baselines and to begin long-term tracking, starting with blood, urine and toenail samples to measure biomarkers. The long-term study also will track participants’ seafood consumption.
Wide range of field testing
Besides recruiting participants, the study depends on pulling together disparate field testing compiled in the days, weeks and months after the storm. As with worker data, sources includes government agencies, independent university researchers and even contractors hired by BP.
Converting the information into usable data, she said, is tedious. “There are plenty of records, but nobody has ever put it together for the purpose that we are using it for.”
Her team also is checking and rechecking the figures, particularly on tests performed by BP contractors. One of the problems, she said, is that existing tests and acceptable government standards for many toxins were not established with oil spills in mind.
Environmental Protection Agency tests might measure global air quality. Occupational safety tests measure toxins in workers’ confined spaces.
“Those tests won’t measure exposure from random wind blowing oil fumes to a certain area on a given day,” she said.
Healthy people needed, too
Attempting to control for those variables, the intention is for Sandler’s team to establish an “expectation of exposure.”
“We’ll be able to say, ‘OK, if you were holding a hose on boats over fire, this was the average exposure,’ ” she said. “Then we’ll have workers in our study who had that job. We won’t have a measure for that worker in our study, but we will know, on average, workers who had their job would have an expectation of a certain exposure.”
Then, over the course of monitoring participants, researchers will begin to draw their conclusions. Sandler said the team would publish findings regularly, and she noted that her efforts have already drawn interest from Capitol Hill.
Sandler emphasized that a successful study must include as wide a range of participants as possible, in terms of geography, post-spill experience and general health status.
“What we’ve found so far is that people are most likely to call us if they are sick,” she said. “We need healthy people, too. This can’t just be people who are sick and think it’s because of the oil spill.”
She also noted that privacy laws protect participants’ information.
“We’re not going to share any health information,” she said. “We’re not going to help or hurt anyone’s individual lawsuits. Whatever anyone tells us cannot be disclosed, and none of our findings will identify individuals.”
The study does not provide medical care, although Sandler said the federal contractor firms conducting in-home visits are trained to refer participants to local providers if they need care.
Bill Barrow can be reached at email@example.com or 504.826.3452.