The Effect of Dysregulated Light on People with Dark Pigment Skin

By Emelita Pupo, University of Miami; Dr. Girardin Jean-Louis, Professor of Psychiatry and Neurology, University of Miami; Scott Zimmerman, CEO, Silas Inc.

Dysregulated Light (DL) – lighting conditions that result in the impairment of the normal regulatory metabolic, physiological, or psychological processes in the body.

The forced displacement of large numbers of Blacks from lower latitudes to higher latitudes exposed generations of Black/African Americans to significantly lower levels of sunlight compared to their ancestorial origins. The residual impact of redlining practices has also led to most Blacks living and working in neighborhoods with less green spaces, higher temperatures, and over-lighting at night, compared to white neighborhoods. Blacks are less likely to get sunlight during the day and are more likely to be exposed to artificial light at night (light pollution) as shown in Figure 1.

Figure 1: Distribution of log-transformed light (lux) comparing Blacks (closed circles) and Whites (open triangles) in Brooklyn, NY. Time series data were folded at 24 hrs, and 30-min averages were computed.(1)

Within this DL environment, African Americans have been more likely to suffer from cardiometabolic, autoimmune, and psychological ailments than other population groups. More recently, urbanization of sub-Saharan Africa has resulted in hypertension prevalence increasing from one of the lowest in the world to the highest in just a few decades. Despite these warning signs, developed countries are mandating the largest reduction in solar exposure in human history, eliminating the ultraviolet (UV) and near infrared (NIR) portions of sunlight from our homes, offices, and schools, where we now spend 93% of our time.

Too Little Sunlight Is Worse Than Too Much

DL negatively impacts our health by disrupting the reactive oxygen species (ROS) balance maintained in all lifeforms (plants and animals) as described by Mittler.(2)

Figure 2: Maintaining ROS within a range provides cells with supportive functions including protection against pathogens. The optimum basal level for a given cellular process changes with age, gender, ethnicity, activity level, and health. Chronic exposure to too little ROS or too much ROS causes cellular processes to decline.

As stated in Mittler, “Metabolism requires therefore an optimum range of ROS levels that enable the plant to achieve its maximal growth and developmental potential.”

It appears that, in our attempt to save energy, we have created artificial environments that are cytostatic by eliminating UV and NIR from our homes. In nature we are never exposed to UV or visible light without an excess of NIR to induce increased blood flow and oxygenation. Vitamin D deficiency from lack of UVB exposure is already a problem within the Black community.

Quantifying the Impact of DL Using ROS

Using the methodology in Zimmerman and Reiter(3), it is possible to estimate and compare the ROS levels generated in the body from a wide range of sources (sunlight, atmospheric ROS, exercise, etc.). Fairer skin type II is adapted to lower ROS, while the darker skin type VI is adapted for higher ROS. Low ROS lifestyles have been shown to increase our risk of myopia, obesity, dementia, rickets, sleep disruption, infectious diseases, infertility, anxiety, and a host of autoimmune diseases.

Each part of the solar spectrum interacts with different cellular processes. It is reasonable to argue that the body assumes and depends on being exposed to sunlight (280nm to over 3000nm). LED lighting/displays (400nm to 650nm) and UV/NIR blocking windows have become a primary source of DL in modern spaces.

Cognitive Learning (opportunity to maximize everybody’s potential)

Multiple studies show enhanced cognitive learning in children outdoors in sunlight versus indoors. Other studies show the benefit of green spaces and forests on anxiety and mood. Optically, it has been shown that the NIR portion of sunlight is guided deep into the cerebral cortex and that virtually all cells in a young child “see” at least a portion of the solar spectrum. From an optical/ redox biology perspective, eliminating NIR from our classrooms may be disproportionately harmful to young Black children.

Expansion of green spaces in urban spaces, replacement of UV/NIR blocking windows, school schedule, reduced exposure to visible-only LED light sources, and increased outdoor activity all need to be considered. Just a one hour walk in nature (90% NIR) has been shown to lower hypertension, improve blood sugars, elevate mood, and reduce anxiety.

Light Pollution

Despite DOE intentions, LEDs have led to excessive use of artificial lighting at night, especially in Black neighborhoods. Nadybal explains that these disparities in increased ambient light exposure are likely due to racial/ethnic differences rather than geographical differences.(5) In general, Blacks have lived for decades trying to sleep and work in DL environments that have exposed them to high levels of light pollution at night and insufficient light levels by day with associated negative consequences. Understanding the impact longterm nocturnal light exposure has had on Black communities may lead to reduced diabetes, hypertension, stroke, and obesity.(6)

Conclusion

Dysregulated Light (DL) has been shown to be a factor in a wide range of diseases ranging from myopia to hypertension to dementia. Chronic DL has both physiological and psychological effects experienced for generations within the Black community. Our failure to quantify the impact of DL and assign value to sunlight and darkness has resulted in modern living conditions that are cytostatic for everyone. ROS density models appear to provide a useful metric to compare various DL conditions across ethnic groups and sources. Ironically, the remedies to DL could reduce global energy consumption by providing fewer higher quality lights only where and when they are needed and tailored to the specific health requirements of the individual.

Works Cited

1. Jean-Louis,G. Kripke,D.F., Elliott,J.A., Zizi,F., Wolintz,A.H., and Lazzaro,D.R. Daily illumination exposure and melatonin: influence of ophthalmic dysfunction and sleep duration. J. Circadian. Rhythms. 2005. Dec. 1;3:13. 2005, 3: 13.

2. Mittler R, (2017) ROS are Good. Trends Plant Sci 22(10):11-19. doi: 10.1016/j.tplants.2016.08.002

3. Zimmerman SM, Reiter RJ (2019) Melatonin and the optics of the human body. Melatonin Res 2: 138-160. doi. org/10.32794/mr11250016.

4. Zimmerman, S. and Reiter, R.J. 2022. Transient responses of melatonin to stress. Melatonin Research. 5, 3 (Sep. 2022), 295-303. doi.org/10.32794/mr112500133.

5. Nadybal, S. M., Collins, T. W., & Grineski, S. E. (2020). Light pollution inequities in the continental United States: A distributive environmental justice analysis. Environmental research, 189, 109959. https://doi.org/10.1016/j. envres.2020.109959

6. Office of Minority Health. Heart Disease and African Americans - The Office of Minority Health. (n.d.). Retrieved August 1, 2022, from https://minorityhealth.hhs.gov/omh/browse.aspx?lvl=4&lvlid=19