A new study from the Center for Interdisciplinary Chronobiological Research at Israel’s University of Haifa has found an additional link between Light At Night (LAN) and cancer.

This research joins a series of earlier studies carried out at the University of Haifa that also established the correlation. “High power light bulbs contribute more to ‘environmental light pollution,’ which the study has shown is a carcinogenic pollution,” notes Prof. Abraham Haim, who headed the study.

Earlier studies at the university have shown that people living in areas that have more night-time illumination are more susceptible to prostate cancer in men and breast cancer in women.

The researchers’ hypothesis was that LAN harms production of melatonin, a hormone that is released from the pineal gland during the dark part of the 24-hour cycle and which is linked to the body’s cyclical night-day activity and seasonality. When this hormone is suppressed, the occurrence of cancer rises.

The researchers note that: “Exposure to LAN disrupts our biological clock and affects the cyclical rhythm that has developed over hundreds of millions of evolutionary years that were devoid of LAN.

Light pollution as an environmental problem is gaining awareness around the world, and the World Health Organization’s International Agency for Research on Cancer (IARC) has already classified working the night shift as a higher grade of cancer risk.”