LED street light­ing poses po­ten­tial risks

The Guardian (Charlottetown) - - OPINION - BY JIM MUNVES Jim Munves, Char­lot­te­town, is a P.E.I. au­thor, green en­ergy sup­porter and na­ture lover.

Here on P.E.I., as in many mu­nic­i­pal­i­ties in Canada and the U.S., The present high in­ten­sity sodium, or old fash­ioned in­can­des­cent bulbs that light our streets, are be­ing re­placed with a new form of LED (light in­ten­sity diode) light­ing which prom­ises to pro­duce more il­lu­mi­na­tion for less en­ergy in­put, thereby, as most elec­tric­ity is gen­er­ated by fos­sil fu­els, re­duc­ing pro­duc­tion of green­house gases that cause global warm­ing.

Al­though the en­vi­ron­men­tally friendly im­pact of use of the new LEDs and at­ten­dant cost sav­ings be­cause of re­duced en­ergy use, ap­pear at­trac­tive; there is con­cern over the ef­fects of this form of light­ing on our health.

In July 2016, the Amer­i­can Med­i­cal As­so­ci­a­tion adopted an of­fi­cial pol­icy state­ment on street light­ing: cool it and dim it. It rec­om­mends that the colour tem­per­a­ture of the LEDs be no more than 3000 Kelvin, (K). An or­di­nary in­can­des­cent bulb’s tem­per­a­ture is about 2400K. A can­dle is around 1800K.

On this scale, the higher the tem­per­a­ture, the more the light is emit­ted at the blue end of the spec­trum. Un­for­tu­nately, the new street-light­ing LEDs are at 4000 to 5000 K. Above 3000K, light sup­presses hu­man mela­tonin pro­duc­tion. This can cause sleep prob­lems; such light also scatters more in our eyes, threat­en­ing dam­age to the retina.

It can also be un­com­fort­ably glar­ing, mak­ing walk­ing and driv­ing at night less safe. A Septem­ber 2016 Toronto Public Health brief­ing on Health Ef­fects of LED street light­ing noted that sleep dis­rup­tion was “as­so­ci­ated with an in­creased in­ci­dence of di­a­betes, obe­sity, heart dis­ease, cog­ni­tive and af­fec­tive im­pair­ment, pre­ma­ture ag­ing and some types of can­cer.”

Ot­tawa and other mu­nic­i­pal­i­ties, fol­low­ing the AMA warn­ings, are lim­it­ing LED tem­per­a­tures to 3000K or less. While re­search con­tin­ues, it will be sen­si­ble to be cau­tious about re­plac­ing street light­ing with high tem­per­a­ture (4000 – 5000K) LEDs.

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