Exposure to Dust at the World Trade Center Linked to Liver Disease in Early Responders

Early responders to the World Trade Center after the 9/11 attacks are associated with a higher likelihood of liver disease, according to a long-term follow-up of responders.

Nearly 20 years after the 9/11 attacks, researchers have found that early responders who arrived at the World Trade Center have a higher likelihood of developing liver disease compared with those who arrived to the site later in the rescue and recovery efforts.

The study, which linked increased liver disease risk with the quantity of toxic dust that workers were exposed to right after the attacks, was published in the American Journal of Industrial Medicine.

Given the liver’s role in detoxifying xenobiotics, the liver is commonly targeted by chemical exposures in the workplace, the authors wrote. At the World Trade Center, people were exposed to particulate matter and chemicals that could not only cause liver damage, but also increase the risk for toxicant-associated fatty liver disease (TAFLD). The most serious form, toxicant-associated steatohepatitis, can lead to liver failure and liver cancer.

“In the aftermath of the 2001 [World Trade Center] attack, over 20,000 men and women responders were exposed to dust, airborne particulates, and chemicals known to cause hepatoxicity,” the authors explained.

They evaluated 1788 World Trade Center responders, who were largely male (83.7%). They categorized the responders and their exposure into 5 groups based on arrival time:

  • On September 11, arrival with the dust cloud (n = 318; 17.8%)
  • On September 11, arrival without the dust cloud (n = 324; 18.1%)
  • On September 12 or 13 (n = 532; 29.8%)
  • On September 14 to the end of September (n = 448; 25.1%)
  • October and beyond (n = 166; 9.3%)

These responders are being monitored by Mount Sinai’s World Trade Center Health Program Clinical Center of Excellence.

“Our study showed that continued monitoring for liver disease is warranted in World Trade Center responders—such as law enforcement, fire, and recovery workers in any field at the site—particularly those who arrived at or shortly after the attacks and had a higher exposure to the toxic dust,” the study’s senior author, Claudia Henschke, MD, PhD, professor of diagnostic, molecular, and interventional radiology at the Icahn School of Medicine at Mount Sinai, said in a statement. “At the moment, there are no protocols to monitor responders for liver disease, so this study points to the need to further study this issue in this at-risk population.”

Of the overall cohort, 14.4% had liver attenuation with Hounsfield units (HU) less than 40 on their earliest CT, which occurred a median of 11.3 years after September 11, 2001. However, there was a significant difference by time of arrival.

As mean liver attenuation decreases, liver steatosis increases. Lower liver attenuation was increased in prevalence among responders who arrived earlier: 17.0% of September 11 arrivals, 16.0% of September 12-13 arrivals, 10.9% of September 14-30 arrivals, and 9.0% of October or later arrivals.

“Our previous work found evidence of liver disease was three times higher in the lung scans of World Trade Center responders compared to other patients’ lung scans, so this new study suggests that responders who arrived at Ground Zero earlier should receive enhanced monitoring for liver disease,” said the study’s first author, Artit Jirapatnakul, PhD, assistant professor of diagnostic, molecular, and interventional radiology at Icahn Mount Sinai. “Now that we have this link, the next step is to understand why or how the toxic dust actually causes liver damage.”

Reference

Jirapatnakul A, Yip R, Branch AD, et al. Dose-response relationship between World Trade Center dust exposure and hepatic steatosis. Am J Ind Med. Published July 30, 2021. doi:10.1002/ajim.23269