Why LED Light is Becoming Increasingly Bad for Your Health

New light bulb regulations that aim to provide bright white light at the lowest energy cost have ignored the health-giving features of the natural daylight spectrum

We think we are so clever as a human race. In the last fifty years, we have invented personal computers, the internet, HVAC, and LED lights so that we can now sit indoors and work and play in comfort at any time of day or night.

As a result, an ever-increasing proportion of the population has moved indoors. In 1900, 41% of American jobs worked outdoors on farms; now, it is only 1%. In today’s world, the average person spends 93% of their time indoors under artificial lights.

But, those people who spend the most time outdoors every day are far healthier and live longer than those who are mostly confined to the indoors. This has now been repeatedly shown in large-scale studies tracking daily light exposure and the health of tens of thousands of people. For more remarkable insights into what we have done to ourselves by moving indoors, see my book THE LIGHT DOCTOR.

New Light Bulb Regulations are Compounding the Health Problem

A broad range of different types of lighting used to be allowed. But the US Department of Energy (DOE) has been tightening the screws by introducing and enforcing minimum lumens per watt standards which only look at the visual brightness of a light and not its health-giving properties. The problem is that our visual sensation of brightness measured in Lumens (1924 V(λ) luminosity function) comes predominantly from the green and yellow wavelengths in a light, and not from its blue or red wavelengths, or its invisible ultraviolet and infrared.

The sun delivers a broad range of light wavelengths at the earth’s surface, including invisible ultraviolet, visible colors from violet to blue to green to yellow to red, and invisible infrared, each of which provides specific health benefits. In contrast, the lumens value used in DOE regulations is determined by the 1924 V(λ) luminosity function, which measures the intensity of a much narrower range of color wavelengths, with 555 nm green having the greatest contribution, and with minimal input from blue or red

In 2023, a 45 lumens per watt minimum standard was introduced which effectively banned all incandescent and halogen light bulbs. Then in 2028 DOE will tighten the screws even further with a 125 lumens per watt rule. As a result virtually all light bulbs will become narrow spectrum blue pump LEDs.

The Essential Differences between Natural Outdoor Daylight and Indoor LED Light

So, what is the difference between most indoor LED lighting and outdoor natural daylight? Both enable you to read a book or perform your daily tasks. But they differ in two important ways: light intensity and wavelength composition.

Comparison of spectral wavelength composition of natural outdoor daylight on a very dark cloudy day (5000 lux) with an indoor room brightly lit (500 lux) by LED lights that can meet the new DOE 125 lumens per watt rule

Light Intensity

The light intensities we use indoors are typically about 100 times less than outdoor daylight. To demonstrate the contrast between the relative color wavelength composition of artificial LED light and daylight in the Figure above, I had to compare a very bright room light (500 lux) with a very dark cloudy day outdoors (5000 lux). Otherwise, the LED light curve would be almost flat on the baseline if we compared it to a 50,000 lux sunny day.

Wavelength Composition

What you can see in the Figure above is that the type of blue-chip LED lights that can meet the new US Department of Energy (DOE) 125 lumens per watt minimum for light bulbs, which goes into effect in 2028, has a very artificial and limited light spectrum. It has no ultraviolet or violet light, relatively little sky-blue light and very little red and no infrared. It does have relatively more green and yellow wavelengths because those are required for human vision, but they are at much lower levels than we see outdoors.

What is missing from this DOE-compliant LED light spectrum are the parts of the natural light spectrum that are essential for health. The Table below shows the vital health-promoting functions of the different visible and invisible wavelengths of natural sunlight.

The peak effective wavelengths for a wide range of the healthy functions of light. Lights that are optimized to provide vision with the lowest electricity consumption deprive us of the critical health-promoting functions of light.

Thus, the only function of light that is enhanced by the 125 lumens per watt rule is the visual perception of brightness. The other light wavelengths that are critical for health are treated as wasted watts, so they cannot easily be provided in a light bulb designed to meet the 125 lumens per watt standard.

What will be banned will include:

1. Broad spectrum LED light bulbs that mimic the natural visible light spectrum

2. Zero blue Circadian night light bulbs that use a violet LED chip instead of a blue chip

3. Light bulbs that provide infrared as well as visible light

4. Light bulbs that also provide bacterial decontamination

5. Red light bulbs for nighttime use

So, in summary, the LED light bulbs we will be forced to live with - unless we overturn the new 125 lumens per watt rule - are designed to aid vision but not to provide the many essential functions of healthy light.

Call to Action

We are taking advantage of the change of administration in Washington DC to seek to overturn the Department of Energy regulations which require all regular light bulbs to meet a 125 lumens per watt energy standard by 2028.

A petition has been drafted to repeal the 125 lumens per watt rule. If you are interested in supporting this, please sign up for the Campaign for Healthy Lighting at https://circadianlight.org/campaign/, and I will keep you informed on the next steps.

REFERENCES

[1] Kalajian TA, Aldoukhi A, Veronikis AJ, Persons K & Holick MF (2017) Ultraviolet B Light Emitting Diodes (LEDs) Are More Efficient and Effective in Producing Vitamin D3 in Human Skin Compared to Natural Sunlight. Scientific Reports 7: 11489 | DOI:10.1038/s41598-017-11362-2

[2] Torii H et al (2016) Violet Light Exposure Can Be a Preventive Strategy Against Myopia Progression. http://dx.doi.org/10.1016/j.ebiom.2016.12.007

[3] Bache SE et al (2018) Universal decontamination of hospital surfaces in an occupied inpatient room with a continuous 405 nm light source. Journal of Hospital Infection 98: 67-73 https://doi.org/10.1016/j.jhin.2017.07.010

[4] Revell VL, Arendt J, Fogg LF, and Skene DJ (2006) Alerting effects of light are sensitive to very short wavelengths. Neuroscience Letters 399: 96–100.

[5] Maisels MJ and McDonagh AF (2008) Phototherapy for Neonatal Jaundice. N Engl J Med 358: 920-928

[6] Moore-Ede M., Heitmann A and Guttkuhn R. (2020) Circadian Potency Spectrum with Extended Exposure to Polychromatic White LED Light Under Workplace Conditions J Biol Rhythms 35(4): 405–415 (2020).

[7] Martin LF et al (2021) Evaluation of Green Light Exposure on Headache Frequency and Quality of Life in Migraine Patients: A Preliminary One-way Cross-over Clinical Trial. Cephalalgia 41: 135–147. doi:10.1177/0333102420956711.

[8] Illuminating Engineering Society. CIE photopic luminous efficiency function https://www.ies.org/definitions/cie-photopic-luminous-efficiency-function/ Archived at https://perma.cc/5PEN-ZZ7B

[9] Yang K (2021) Hair Growth Promoting Effects of 650 nm Red Light Stimulation on Human Hair Follicles and Study of Its Mechanisms via RNA Sequencing Transcriptome Analysis. Annals of Dermatology 33: 553-561 https://doi.org/10.5021/ad.2021.33.6.553

[10] Shinhmar H et al (2020) Optically Improved Mitochondrial Function RedeemsAged Human Visual Decline. Gerontol A Biol Sci Med Sci, 2020, 75: e49–e52 doi:10.1093/gerona/glaa155

[11] Mason MG et al (2014) Re-evaluation of the near infrared spectra of mitochondrial cytochrome c oxidase: Implications for non-invasive in vivo monitoring of tissues. Biochimica et Biophysica Acta 1837: 1882–1891 http://dx.doi.org/10.1016/j.bbabio.2014.08.005