Artificial night time lighting is associated with an increased risk of prostate cancer in men. According to research by Professor Boris A. Portnov and colleagues of the University of Haifa, exposure to artificial light sources at night increases the risk of prostate cancer the more a man is exposed. In previous research, the same team found an association between artificial light exposure and increased risk of breast cancer.
Using data obtained from the International Agency for Research on Cancer, the incidence of cancer in men from 164 countries, was compared with levels of lighting at night. Satellite images were obtained from the Defense Meterological Satellite Program, which reveals levels of artificial lighting across the globe. Adjustments were made to data which allowed the research team to calculate the amount of artificial light exposure per person.
Countries were classified into one of three groups according to the amount of artificial light they were exposed to. Countries with low exposure were found to have approximately 67 prostate cancer patients per 100,000 inhabitants. This climbed to 87 per 100,000 in medium exposure countries and to 157 per 100,000 in high light exposure countries.
Despite the association, there is no proven link between artificial light exposure and prostate cancer. Researchers speculate that suppression of melatonin production and the immune system may be occurring as a result of internal body clock disruption, caused by problems in adjusting to artificial light conditions.
Researchers say, "this does not mean that we have to go back to the Middle Ages and turn the lights out in the country. What it means is that this link should be taken into account in planning [a] country's energy policies".
The research is published in the journal Chronobiology International.
Published On: February 04, 2009