HAIFA, Israel, Feb. 3 (UPI) -- Israeli and U.S. researchers suggest a link between artificial light and prostate cancer.
The University of Haifa study finds the incidence of prostate cancer in those countries with low light exposure was 66.77 prostate cancer patients to 100,000 inhabitants. An increase of 30 percent was found in those countries with medium exposure -- 87.11 patients per 100,000 inhabitants.
Researchers Abraham Haim, Boris A. Portnov and Itai Kloog of the University of Haifa along with Richard Stevens of the University of Connecticut, however, said the countries with the highest level of exposure to nightly artificial light demonstrate a jump of 80 percent -- 157 patients per 100,000 inhabitants.
"This does not mean that we have to go back to the Middle Ages and turn the lights out on the country," the researchers say in a statement. "What it means is that this link should be taken into account in planning the country's energy policies."
The researches examined the influence of various factors including the the amount of artificial light at night per person. Amounts of artificial light were determined using data from Defense Meteorological Satellite Program images, electricity consumption and other factors.
The incidence of three types of cancer -- prostate, lung and large intestine -- is based on data from 164 countries collected by the International Agency for Research on Cancer.
