Product Class
Contact Us
Add:Unit I 10/F Blk B, Marvel Ind. Bldg 17- 23 Kwai Fung Crescent NT. KL .HK
Tel :00852 -24813389   
Fax:00852 24289521
E-mail fernandow@126.com

Outdoor-lighting research suggests strong LED impact in suppressing melatonin

It's not the first time that the impact of white solid-state light (SSL) on human health has been questioned, but a new research project says that LEDs, for the same photopic flux output, increase "pollution in the scotopic and melatonin suppression bands" by five times relative to high-pressure-sodium (HPS) sources. The publication originating from institutions in Italy, Israel, and the US recommends regulatory limits for future SSL products.

The research entitled "Limiting the impact of light pollution on human health, environment, and stellar visibility" was published in the Journal of Environmental Management. The authors include 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 research studied both LED and metal-halide (MH) sources relative to reference HPS sources. Both the LED and MH sources produce white light that includes more blue content at shorter wavelengths than do HPS sources that produce orange- to yellow-tinted light. Like much similar research, the new study apparently didn't test actual subjects, but rather relied on prior research on melatonin-suppression levels relative to spectral content. The researchers came to the conclusion that MH lights suppress melatonin at a rate 3 times greater than HPS lights and LEDs suppress melatonin at 5 times the HPS rate.

The magnitude of the impact of melatonin suppression remains in debate. The secretion of melatonin has been shown as key in normal sleep/wake cycles and circadian rhythms. Some researchers also believe that it has "anti-oxidant and anti-cancerous" properties as the new research points out.