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WHY and HOW ARTIFICIAL LIGHTING in DESIGN AFFECT HEALTH & WELLBEING

Lighting is one of the most neglected aspects of interior design projects, despite the fact that lighting is able to enhance, highlight, and transform an area into a design feature, enhance an artwork, and create a sensory experience.


WHAT IS LIGHT?


Light is simply electromagnetic radiation, a form of energy that travels in waves of different sizes with different amplitudes, wavelengths, and frequencies.


Visible light is defined as the part of the electromagnetic spectrum that is detectable by the human eye. Light is a small portion of the electromagnetic spectrum, from 380-780 nanometers (nanometer is a billionth of a meter).


Before any application of lighting, we must begin with the understanding of the workings of the human eye. The human eyes collect information in a form that can be delivered to the brain. The lens of the eye focuses light onto the sensitive retina , like the lenses of a camera focuses light on the surface of a film or plate. Withouth light, they eye cannot operate to see colours.





This means that the sensation of color does not exist without light. Natural light, hence the sunlight is composed of colors of the spectrum. The color red has a longer wavelenght, while the violet the shortest. Natural light is simply an electromagnetic field frequency that allow us the see the world in color.



HEALTH CONCERNS OF LED LIGHTING


"Electric lighting became available less than 150 years ago but it provides a convenience most people would find difficult to live without today. The use of artificial light has undoubtedly increased our productivity by effectively extending the working day and improved our safety. However, many of our modern lighting sources also come with an electromagnetic radiation and hazardous material burden." {1}


Energy efficiency has been the motivation behind the shift to LED lighting as our primary lighting source. The main problem with LEDs is the fact that they emit primarily blue wavelengths and lack the counterbalancing, healing and regenerative near-infrared frequencies. They have very little red in them, and no infrared, which is the wavelength required for repair and regeneration, which is the same wavelength we receive from the Sun.

The excess of blue light not only affects Circadian Rhythm, but also generates Reactive Oxygen Species (ROS) within the body that contribute to inflammation. Essentially, LED bulbs increase damage to the human body and decrease its innate ability to recover.


Another issue with LED is the flickering rate.


Flicker (also called temporal modulation) refers to rapid and repeated changes in the brightness of a light source. Invisible flicker refers to flicker too fast for most people to consciously perceive. This limit is referred to as the Critical Flicker-Fusion Frequency (CFF) and varies amongst individuals. For most people, CFF is between 60 and 90 Hz but can be higher for sensitive individuals.


Certain people tend to be more sensitive to flickering light - children, people with autism, and those susceptible to vertigo, headaches, and migraines. Biological effects have been found for both visible and invisible flicker at the lower frequencies. The health effects for flicker < 200Hz include:


• Headaches and migraines • Eye strain and blurred vision • Reduced performance of visual tasks • Inability to focus • Increased behavioral issues of the autistic • Fatigue •Seizures at frequencies between 3-70 Hz, with 15-20 Hz the most hazardous {2}


HOW TO SPECIFY HEALTHIER LED LIGHTS


- Choose LED with a full light spectrum of a minimum CRI = 95 (to ensure infrared frequencies are present).


- LED strip lights should have a traditional transformer, not a SMPS driver as this emits very high magnetic fields.


- The flickering rate should be between 0 and 1 %, not any higher.


- The transformers location should be carefully planned to avoid vicinity with sleeping areas and living area where people spend most of their time. This is usually coordinated by the electrical engineer with the lighting consultant/supplier.


COMMON DESIGN TRENDS TO AVOID, IF YOU WANT TO IMPLEMENT LIGHTING IN A HEALTHY WAY


-Do not place LED strip lights behind the headboard of the bed as it emits high magnetic fields due to the transformer that converts AC current to DC current.


-Do not place pendent lights next the bed, on top of the bedside tables, as they emit high electromagnetic fields even when turned off, interfering with our sleep and cells recovery.


-Unplug or turn off the switch of bedside table lamps before sleeping, to avoid electric fields emissions at night.


-Use standard on and off traditional light switches (no dimmers, no automated lights, no wireless connected lights, as these create high magnetic fields and dirty electricity).



LED strip lights should not be placed behind the bed.



References


{1} Building Biology Institute, USA, "Electric light: options and health impacts" , page 27.


{2} Building Biology Institute, USA, "Electric light: options and health impacts"..

-Roberts, J.E., Wilkins, A.J. 2013. Flicker can be perceived during saccades at frequencies in excess of 1 kHz. Lighting Research and Technology

-Lee, C.S., Lee, J.H., Pak, H., Park, S.W., Song, D.W. 2018. Phantom array and stroboscopic effects of a time-modulated moving light source during saccadic eye movement. Lighting Research and Technology

-Inger, R., Bennie, J., Davies, T. W., Gaston, K. J. 2014. Potential biological and ecological effects of flickering artificial light.

-Wilkins, A, J. Veitch, Lehman, B. 2010. LED lighting flicker and potential health concerns: IEEE standard PAR1789 up- date. 2010 IEEE Energy Conversion Congress and Exposition, Atlanta



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