Monday, December 3, 2007

Shift work may cause cancer

Shift workers and firefighters have a higher risk of cancer than the general population and such work should be classified as probably or possibly carcinogenic, the International Agency for Research on Cancer said on Friday.

A team of 24 scientists who sifted through the evidence said more studies must confirm the link, but found that shift work that disturbs the body's internal clock appears to have cancer-causing effects, too.

This internal clock regulates circadian rhythms, a complex system that signals cells to produce various hormones at various times.

"Shiftwork that involves circadian disruption is probably carcinogenic to humans," the French-based IARC, the cancer agency of the World Health Organization, said in a statement. "Occupational exposure as a firefighter is possibly carcinogenic to humans," it added.

The statement, published as what the IARC calls a monograph, could affect a significant number of people.

"Nearly 20 percent of the working population in Europe and North America is engaged in shiftwork. Shiftwork is most prevalent in the health-care, industrial, transportation, communications, and hospitality sectors," the IARC said

-Shift work may cause cancer, world agency says

Some of their interesting monographs;
Betel-quid and areca-nut chewing and some areca-nut-derived nitrosamines

Smokeless Tobacco Products

1 comment:

Ed Coburn said...

Be careful in interpreting this. The study found a correlation, not a causal relationship. What is behind this modest increased risk, for specific types of cancers, for certain workers in a few specific industries? We don't know. Could be shiftwork, or the shiftworkers' behavior, or their industrial environment.

Until further research is done, shiftworkers and their employers should take reasonable steps, based on the best scientific evidence, to protect alertness, health and safety. Shiftworker lifestyle training should be a no-brainer. (I wrote about shiftworker lifestyle training in my recent post to our blog at

Ed Coburn
Executive Director
National Shiftwork Information Center