CHICAGO (CBS) — Firefighting may be even more dangerous a job than we already knew.

As WBBM Newsradio’s Bernie Tafoya reports, a medical study by the Illinois Fire Service Institute at the University of Illinois indicates that the arteries of firefighters – even young firefighters – take a pounding and stiffen in three hours of work at a fire.

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

The study in the journal Vascular Medicine indicates that the U of I researchers found that the temporary changes in the arteries are similar to those for people who do resistance training or aerobic exercise.

What is not clear is whether that artery stiffness contributes to heart attacks that happen right after fires.

The participants in the study were medically cleared for the study, but many were overweight. They were all men, and ranged in age from 19 to 48 with an average age of 29.

Researchers Gavin Horn of the Fire Service Institute, and Bo Fernhall, a professor of kinesiology, conducted the study.

Last year, according to the National Fire Protection Association, there were 72 on-duty firefighter deaths. Thirty-nine of them were related to stress or other medical issues, and 34 were said to be heart-related.

(TM and © Copyright 2011 CBS Radio Inc. and its relevant subsidiaries. CBS Radio and EYE Logo TM and Copyright 2011 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed. The Associated Press contributed to this report.)

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