Ground Zero workers who entered the initial dust cloud from the Sept. 11, 2001 terrorist attacks in the first two days may have a higher risk of heart attacks and strokes than those who arrived later, researchers said.
A study of 31 people found those who were most exposed to the toxic dust had worse dysfunction of their blood vessels than workers who were at the scene after Sept. 13. The results were reported today at the annual meeting of the American Heart Association in Orlando, Florida.
The dust cloud contained very small particles, called particulate matter, that have been linked to potentially fatal blood clots in the legs, as well as heart attacks, premature death, decreased lung function and asthma, according to the U.S. Environmental Protection Agency. The study has implications for people who live in areas with lots of air pollution as well, said study author Mary Ann McLaughlin.
“In the last two years or so, there have been more epidemiologic studies showing an increased cardiovascular risk from air pollution,” said McLaughlin, who is an associate professor of cardiology at Mount Sinai School of Medicine in New York, in a telephone interview. “We’re trying to look at the changes in physiology and maybe find the mechanism.”
Studies of first-responders at the World Trade Center have shown a 12-times higher rate of asthma and a 19 percent increased risk of cancer.
The 19 people with high exposure to particulate matter had significantly worse endothelial dysfunction, a condition where the membrane that lines the inside of heart and blood vessels doesn’t work properly, than the later responders, the study found. The condition has been linked to increased risks of heart attacks and stroke, according to the research.
It is particularly worrisome because the people studied were relatively young and healthy, with an average age of about 46, McLaughlin said.
An MRI scan of the group with more intense exposure showed that cholesterol plaques in their blood also had signs of increased blood vessel growth, compared to the less exposed workers, the study showed. The increased blood vessel growth is linked to inflammation, which plays a role in heart disease, McLaughlin said.
“It’s akin to second-hand smoke,” said Vincent Bufalino, a cardiologist and president of Midwest Heart Specialists in Naperville, Illinois, in an interview. He wasn’t involved in the study “It’s a warning to health care providers that those who have had this high-intensity exposure should be watched closely.”
The patients in the study are a subset of a 2,500-person group being followed after the attacks, McLaughlin said. Other heart abnormalities had been found in the larger group, compared with people who hadn’t been at the site, she said. Next steps include seeing whether patients with negative findings on the tests might benefit from statins or aspirin in holding off heart attacks or stroke.
More than 50,000 people, including firefighters, police and construction workers, were exposed to chemicals at the site while rescuing survivors, recovering the dead and cleaning the site or surrounding buildings, wrote James Melius, an administrator for the New York State Laborers’ Health Fund, in an editorial published by The Lancet in September.