Research suggests strong LED outdoor-lighting suppresses body’s melatonin production

Research published in the Journal of Environmental Management asserts that LEDs (white solid-state light) suppress melatonin levels by five times worse traditional high-pressure-sodium sources. 

The research, entitled “Limiting the impact of light pollution on human health, environment, and stellar visibility,” was conducted in a joint effort by Fabio Falchi of Italy's Light Pollution Science and Technology Institute (ISTIL), Christopher Elvidge of the National Geophysical Data Center in Boulder, CO, David Keith of Marshall Design in Boulder, and Abraham Haim of Israel's University of Haifa. The study compared LED and metal-halide (MH) sources, both of which produce white light with more blue content at shorter wavelengths, relative to reference HPS sources, which produce orange-to-yellow tinted light.

It was concluded that MH lights suppress melatonin at a rate 3 times greater than HPS lights and LEDs suppress melatonin at 5 times the HPS rate. Melatonin is a naturally occurring hormone whose secretion corresponds to our natural circadian rhythm. Offsetting the production of melatonin wreaks havoc on the natural sleep/wake cycle.

Source: LED magazine