Study: LED lighting hazardous to public health
HAIFA, ISRAEL – A new international study has found that exposure to white LED bulbs is significantly more harmful to public health than exposure to the orange-yellow light emitted by high pressure sodium bulbs.
The findings by a team of researchers from Israel, Italy and the United States, in a study titled “Limiting the impact of light pollution on human health, environment and stellar visibility” by Fabio Falchi, Pierantonio Cinzano, Christopher D. Elvidge, David M. Keith and Abraham Haim.were recently published in the Journal of Environmental Management.
“White” light, the researchers found emits light at shorter wave lengths (of between 440-500 nanometers) and suppresses the body’s production of melatonin five times more than exposure to orange light.
Orange-yellow light is primarily used for outdoor illumination, such as street lights, road lighting, and mall lighting.
Melatonin is a compound produced in the brain’s pineal gland. It is responsible for regulating the biological clock in humans and animals and is known for its anti-oxidant and anti-cancerous properties.
The landmark study was conducted by astronomers, physicists and biologists from Italy’s ISTIL- Light Polution Science and Technology Institute in Italy, the National Geophysical Data Center in Boulder, Colorado, and the University of Haifa.
Researchers examined different levels of melatonin suppression in various types of light bulbs and recommended measures to save energy and protect public health.
The metal halide bulb which emits a white light and is used for stadium lighting suppresses melatonin at more than three times that of the HPS (high pressure sodium) bulb.
The light-emitting diode (LED) bulb, which also emits a white light, they found, suppresses melatonin at more than five times the HPS bulb.
“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,” Professor Abraham Haim, head of the Center for Interdisciplinary Chronobiological Research at the University of Haifa.
White light should be used where absolutely necessary, the researchers recommend. Lamp posts should be adjusted so that their light is not directed beyond the horizon to reduce light pollution. Lights can also be simply switched off when not in use to reduce “over-lighting” and save energy.
Most Italian regions have legislation to lower the impact of light pollution, but lack regulation on the spectrum emitted by lamps, says ISTIL’s Fabio Falchi.
“Unless legislation is updated soon, with the current trend toward 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.”
“In Israel the Standards Institute should obligate bulb importers to state clearly on their packaging the wavelengths produced by each bulb. This information needs to be brought to the public’s attention, so that consumers can decide whether to buy this lighting or not,” Prof. Haim says.