Science Bulletin Sept/Oct. 2013 | Page 4

Editorials:

Last month I was watching an interesting documentary called “The City Dark”. The film explored light pollution and its effects. One section caught me by surprise. The section delved into the idea that light at night could cause breast cancer. However, the evidence that they presented seemed a little wobbly.

The evidence was first presented by epidemiologist Richard Stevens in the American Journal of Epidemiology. He found that night shift workers have 1 ½ to 2 times the likelihood of getting breast cancer than day shift workers. He believes this is because night shift workers are constantly exposed to light in the day and the night. Studies have show people exsposed to light all day and night have suppression of a hormone called Melatonin. Other studies have shown that Melatonin may slow tumor growth.

Melatonin is a hormone which is produced, according to some scientists at night in large quantities, and in the day in smaller quantities. Stevens claims that our body produces melatonin based on light, not day and night. The study done to prove this was clear and well done. The scientists took blood samples from test subjects exposed to light at night, and in the day.

Noteworthy but I'm skeptical

By Peter Smith