This is a new one. According to this Seattle Times article, you could get cancer by working the night shift.
It is a surprising step validating a concept once considered wacky. And it is based on research that finds higher rates of breast and prostate cancer among women and men whose work day starts after dark.
Next month, the International Agency for Research on Cancer, the cancer arm of the World Health Organization, will add overnight shift work as a probable carcinogen. The American Cancer Society says it will likely follow. Up to now, the U.S. organization has considered the work-cancer link to be “uncertain, controversial or unproven.”
The higher cancer rates don’t prove working overnight can cause cancer. There may be other factors common among graveyard shift workers that raise their risk for cancer.
However, scientists suspect that overnight work is dangerous because it disrupts the circadian rhythm, the body’s biological clock. The hormone melatonin, which can suppress tumor development, is normally produced at night.
Bottom line: if you have to work at night, be sure to sleep in a dark room.