Researchers have found that women who work night shifts for more than 30 years may be at a higher risk of breast cancer
than other women.
The study, published in the British Medical Journal (BMJ), was done by researchers in Canada. They analyzed the careers of 1,134 women with breast cancer and 1,179 women without the disease.
The women, all of the same age, were questioned about their shift work patterns throughout their employment history, and hospital records were used to determine their tumor
Around 1 in 3 women in both groups of the study had worked night shifts. The research revealed that women who had worked night shifts for up to 14 years or for between 15 and 29 years had no increased risk of developing breast cancer. But the women who had worked night shifts for 30 years or more were twice as likely to develop the disease.
In the study, the researchers suggest that the night-time artificial lighting that shift workers are exposed to could be one factor giving rise to the cancer
The researchers believe that long-term exposure to artificial lighting can suppress the production of melatonin.