The influence of artificial light on human health is an area of ongoing research, however the evidence is clear that continuous exposure to a fixed spectrum, intensity and colour temperature of light throughout our working days conflicts with the circadian rhythm effecting the production of hormones. Whilst tunable white lighting systems can help combat this, evidence is mounting that the colour temperature of the light is less critical than the blue spectrum. Given all white LEDs are typically phosphor converted blue sources this can be problematic as changes in colour temperature may simply mask a high blue content of the incorrect wavelength. In particular, cyan waveforms around 480nm appear to be particularly critical to supress melatonin production through the daytime, this is present in natural daylight but absent from most white LEDs and a new generation of products is becoming available that simulate this element of natural daylight which may in time come to replace many of the tunable solutions we are currently familiar with.
As the human cost is the highest expense of any business, improvements in employee attendance and performance can have a substantial effect on profitability over and above the normal focus of reductions in energy consumption and maintenance cost. The higher initial capital cost of human centric lighting systems should be offset against these gains, a long term focus on lifetime costs is critical for widespread industry adoption. Beyond financial returns, potentially greater benefits exist in healthcare and educational applications where current evidence suggests that recuperation times are reduced and educational attainment improved when subjected to lighting which mimics natural daylight.
A similar process is beginning to occur in the external space. Street lighting is commonly being replaced with 3000 kelvin or lower colour temperature sources to minimise the effects on our sleep patterns as well as disruption to wildlife, whilst colour temperature adjustments can help improve visibility for drivers and pedestrians in adverse weather conditions, particularly fog and mist.
It is clear that despite many years of research this is still an area in which there is a great deal more to learn, however there are obvious benefits to both productivity and health when such systems are implemented correctly with a solid understanding of the science undertaken to date.