More than a decade after the 9-11 attacks on the World Trade Center, first responders appear to still be giving their lives for their efforts to save others, according to a report published in the journal Environmental Health Perspectives revealing a 15 percent increase of cancer among those who worked among the debris immediately after the attack.

“World Trade Center rescue and recovery workers were exposed to a complex mix of pollutants and carcinogens,” the study states.

In all, researchers looked at nearly 21,000 participants identified through linkage to state tumor registries in New York, New Jersey, Connecticut and Pennsylvania.

Standard incidence ratios (SIRs) were calculated to compare to the incidence ratios among first responders.

In all, 575 cancers were diagnosed in 552 individuals.

In particular, researchers saw an increase of thyroid, prostate, soft tissue, lymphoid and hematopoietic cancers.

However, when only the 302 cancers diagnosed 6 or more months after enrollment were examined, the rate for all cancers combined fell to 1.06.

However, thyroid and prostate cancer diagnoses remained high when analyzed separately. Furthermore, when it came to “very highly exposed responders" and those exposed to "significant amounts of dust,” all cancers combined showed an increased rate over responders who reported lower levels of exposure.

Ultimately, the researchers warn that the study’s estimates should be “interpreted with caution” due to the short follow-up and lengthy latency period for most cancers, as well as the increased testing and monitoring of the group when compared to the population at large.

“However,” the study explains, “our findings highlight the need for continued follow up and surveillance of WTC responders.”

The study is not the first to find a link to increased cancer rates among the attack’s first responders. A report published last December in the Journal of the American Medicine Association, for example, reported that the group’s risk of developing thyroid cancer doubled in comparison to the rest of the population, and that they were as much as 43 percent more likely to develop prostate cancer and three times more at risk of myeloma.