People working erratic night-time shift patterns would be better served by LED lighting that features the colour blue, Helen Loomes, business development director at Trilux has told Lux’s Health and Wellbeing Conference.
There is mounting evidence that night-shift workers are at risk of serious health problems because the timing of their work goes against the body’s natural clock, disrupting the internal rhythm of genes.
When placed in comparison with day workers, night workers have been found to have increased levels of cardiovascular disease, obesity and cancer.
The evidence is far from casual and the numbers have so worried the International Agency for Research on Cancer that they have classified shift work as a ‘probable carcinogen’.
Up until recently effort has been put into delaying the body's circadian rhythm in an attempt to tackle the problem, but this can be done only by a small amount and is not enough to mitigate against the risks of shift work.
Lighting however, Loomes told the conference, can be used to rewire and retain a regular circadian pulse while working at night.
A number of laboratory and field studies have shown that being exposed to light during the night reduces sleepiness, whilst improving alertness.
It has been found, Loomes reported, that a bright light of greater than 1000 lux can act to suppress melatonin, the hormone that anticipates darkness and prepares the body for sleep.
The production of melatonin is suppressed during the day by our natural blue-rich light environment, it is when the blue starts to wane as the day moves towards night that we begin to feel tired.
The spectral distribution at which melatonin is held at bay peaks at 464nm, which is a very strong blue and manufacturers are able to adjust the light output of their modules to take advantage of this knowledge.
Blue saturation has been done before using fluorescent phosphors, but the result was often considered to be far too cold for many working environments. LED technology is providing much finer adjustment in the make-up of white light though, enabling warmer tones to be created, combining the melanopic peak within the spectrum when required.