University of Haifa - "Light pollution" and cancer

Judy Siegel-Itzkovich

Increasing concern that “light pollution” caused by artificial lighting that reduces the production of the hormone melatonin by the brain’s pineal gland can cause cancer and other diseases has led to new research into which types of electric bulbs cause less potential risk.
Now a University of Haifa researcher and his colleagues who are participating in an international study of the subject have found that nighttime exposure to white-light-emitting diode bulbs – which are actually blue light on the spectrum – commonly used both in outdoor and some indoor lighting suppresses the beneficial hormone’s production five times more than does high-pressure sodium bulbs that emit an orange-yellow light.
Prof. Abraham Haim, with scientists from Italy and the US, just published findings on the subject in the Journal of Environmental Management in an article titled “Limiting the impact of light pollution on human health, environment and stellar visibility.”
The researchers said that since civilization is obviously unwilling to return to the caveman era and live in darkness when the sun goes down, efforts can be made to minimize exposure at night to types of illumination that reduce melatonin production.
“Just as there are regulations and standards for ‘classic’ pollutants, there should also be regulations and rules for pollution stemming from artificial light at night,” said Haim, head of the University of Haifa’s Center for Interdisciplinary Chronobiological Research and the Israeli partner in the research.
(...) From this comparison, it became clear that the metal halide bulb, which gives off a white light and is used for stadium lighting and many other uses, suppresses melatonin at a rate more than three times greater than the HPS bulb, while the LED bulb, which also gives off a white light, suppresses melatonin at a rate more than five times higher than the HPS bulb.
“The current migration from the now widely-used sodium lamps to white lamps will increase melatonin suppression in humans and animals,” the researchers say. Melatonin, a compound that adjusts our biological clock and is known for its antioxidant and anti-cancerous properties(...).

Unless legislation is updated soon, with the current trend toward sources as white LEDs, which emit a huge amount of blue light, we will enter a period of elevated negative effects of light at night on human health and environment. Lamp manufacturers cannot claim that they don’t know about the consequences of artificial light at night,” says Dr. Fabio Falchi of ISTIL.
“As a first step in Israel, for example, the Standards Institution of Israel should obligate bulb importers to state clearly on their packaging what wavelengths are produced by each bulb. If wavelength indeed influences melatonin production, this is information that needs to be brought to the public’s attention, so consumers can decide whether to buy this lighting or not,” Haim added.
The University of Haifa researcher declared in 2008 that exposure to light at night is the most powerful factor in breast cancer besides genetic defects.
Other studies have implicated it in prostate cancer and the development of nearsightedness in children, eyestrain, headaches and sleep disorders.

http://www.jpost.com/Health-and-Sci-Tech/Health/Study-Nighttime-LED-light-increases-risk-of-cancer#!