Nearly 3-Fold Higher Lung Cancer Rates Among 9/11 Responders With Heavier Dust Exposure

More than two decades after the September 11 attacks, new research suggests that responders who worked amid the World Trade Center (WTC) dust and debris face nearly a 3-fold higher incidence of lung cancer. In a large cohort study published Oct. 9 in JAMA Network Open, investigators from Stony Brook University found that severe WTC site exposures were linked to nearly triple the lung cancer incidence seen in minimally exposed responders, even after adjusting for tobacco use and other factors.

Thousands of firefighters, police officers, construction workers and volunteers were exposed to airborne carcinogens while searching for survivors and clearing rubble after the WTC collapse. Previous research has documented respiratory illnesses and reduced lung function among responders, but evidence linking exposure severity to lung cancer risk has been limited. Earlier studies found little or no excess incidence of lung cancer, perhaps because of the long latency period for the disease (i.e., it can take many years to develop after exposure).

To address these uncertainties, lead author Sean Clouston, Ph.D., and colleagues at Stony Brook University’s Program in Public Health and Renaissance School of Medicine analyzed data from 12,334 responders enrolled in a medical monitoring program in Long Island, New York. The study included surviving individuals who were followed for new lung cancer diagnoses beginning at least 10 years after exposure, between July 2012 and December 2023.

Participants completed detailed questionnaires describing their time at WTC sites, including the type of work they did, how long they were there, the amount of dust, the odors and sights they noticed and whether they used protective gear. Based on this information, researchers categorized exposures as mild, moderate or severe. Lung cancer diagnoses were confirmed by clinicians and verified by the Centers for Disease Control and Prevention. The results were adjusted for factors such as smoking status, age and sex.

During the 11-year follow-up period, 118 responders were diagnosed with lung cancer between 2012 and 2023. This corresponded with an incidence rate of 8.7 cases per 10,000 person-years. Compared with responders who experienced mild exposure, those with moderate exposure had an adjusted hazard ratio (AHR) of 1.86 and those with severe exposure had an AHR of 2.9. Certain types of exposure, such as smelling fumes or sewage, were also linked to higher lung cancer rates after adjusting for age, sex and smoking.

“We discovered that responders with more severe exposures to WTC dust had up to 2.9 times greater risk of developing lung cancer compared with minimally exposed responders working on the pile who reported low dust exposure or used personal protective equipment (PPE),” Clouston stated in a news release. Clouston is an epidemiologist and professor in the Department of Family, Population and Preventive Medicine in the Renaissance School of Medicine and director of research for the Program in Public Health at Stony Brook University.

According to Clouston and colleagues, these findings provide the first evidence of an association between WTC exposure severity and lung cancer incidence after a long latency period. The authors noted that the longer follow-up window allowed cases to emerge that earlier studies may have missed, helping clarify the impact of these exposures.

The researchers acknowledged that the study had limitations. Exposure data was self-reported rather than measured and biomarkers were unavailable to confirm exposure severity. They also could not rule out the influence of exposures that occurred before or after 9/11. However, cancer cases in this cohort are considered well-documented because participants receive ongoing screening and treatment through the WTC Health Program.

According to the authors, their analysis offers one of the most comprehensive, population-based assessments to date, quantifying how different levels of WTC dust exposure relate to lung cancer risk. Future research, they wrote, should explore the specific carcinogens present at WTC sites, underlying biological mechanisms and how these exposures may affect long-term outcomes.

Ultimately, the findings highlight the importance of maintaining long-term monitoring and screening for WTC responders, the authors wrote, especially for those who experienced high levels of dust and debris exposure during recovery and cleanup efforts.