integrity of the skin and the nature of pollutants. In addition, the epidermis, the outer layer of skin, acts as a barrier that protects the body from ultraviolet radiation (UV), harmful chemicals, pathogens, bacteria, and viruses. However, long- term exposure to environmental stressors can exceed the skin’s normal defensive potential (Drakaki et al., 2014). Furthermore, through oxidative damage, air pollutants may interfere with normal functions of lipids, DNA, and proteins, leading to skin aging; increased inflammation; allergy conditions; and lipid peroxidation, the process in which free radicals “steal” electrons from the lipids in cell membranes, thus oxidizing fats, lipids, and ceramides and resulting in cellular toxicity, DNA damage to skin cells, increased oil production, pigment spot formation, postinflammatory hyperpigmentation, immune suppression, and overall cell damage (Timms, 2019).
Therefore, effectively “shielding” the skin against pollution exposure should be the goal of every esthetician. Skin care products should be formulated with active ingredients known to improve the skin barrier function by working to scavenge oxidative pollutants and physically shielding the skin, thus reducing the immediate exposure of skin to harmful toxins. However, to develop an effective antipollution treatment plan, skin care professionals must have a better understanding of the damaging effects of heavy metals, ozone exposure, and atmospheric PM. The air pollutants that react the most with skin include ultraviolet radiation (UV), polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), nitrogen oxides (NOx), particulate matter (PM), cigarette smoke, heavy metals, and ozone (Drakaki et al., 2014). The mode of penetration of pollutants differs and depends on the
LIGHT POLLUTION AND ITS EFFECTS ON SKIN HEALTH
spectrum. These wavelengths create the electromagnetic spectrum. Furthermore, the solar spectrum is composed of radiations of various wavelengths having specific effects on the skin. Numerous extrinsic factors related to the environment and lifestyle also affect the appearance of skin (Dupont et al., 2013). However, shorter wavelength radiations in the UV range have higher energy and are potentially more damaging: ● UVC : Fully absorbed by the atmosphere ● UVB : Sunburn and DNA dimer formation that can lead to mutation ● UVA : Oxidative reactions affecting DNA, proteins, lipids, immune suppression, and pigmentation ● Visible light, blue part : Oxidative stress and persistent hyperpigmentation ● Visible light, red part : Oxidative stress ● IR-heat sensation : DNA and oxidative damage ● IRB : Fully absorbed by water in the epidermis and stratum corneum ● IRC : Fully absorbed by water in the epidermis and stratum corneum Additionally, the UV wavelength is the longest, about 10 to 400 nm. It is shorter than visible light but longer than X-rays. What's more, ultraviolet radiation is responsible for vitamin D synthesis in the body, through a chemical reaction dependent upon 5 to 15 minutes of regular midday sun exposure. The sun is the best source of vitamin D made in the skin. Vitamin D is also essential in the production of the chemical serotonin, which promotes feelings of happiness and well-being. The impact of UV radiation on skin has both benefits and risks. It is well known that UV (phototherapy) has been used to treat inflammatory skin conditions such as psoriasis, eczema, atopic dermatitis, and even vitiligo. Moreover, light therapy is emitted in different wavelengths: blue, 420 nm; yellow, 590 nm (kills bacteria); and red light, 630, 650, and 670 nm (treats acne; boosts collagen production; reduces inflammation; minimizes fat; increases cellular function; and repairs sun damage due to photoaging, the environment, and trauma).
Visible light pollution is a known factor in aging, as it provokes inflammation and subsequent age-accelerating inflammatory responses, as well as hyperpigmentation, redness, dehydration, and sensitivity (Giacomoni, 2019; Shatzman, 2018). Visible light is partially absorbed by the melanin in the epidermis as it penetrates the skin. The papillary dermis, which contains subepidermal blood vessels, absorbs blue and green light, thus penetrating the skin down to adipose tissue, where the fat absorbs part of the red photons (Giacomoni, 2019). Light is made up of electromagnetic particles that travel in wavelengths. These waves emit energy, have various lengths and strengths, and can be as long as the universe. Wavelengths have a frequency range of 430 to 750 terahertz (THz), and the shorter the wavelength, the higher the energy. The human eye is privy to only one part of the spectrum: Visible light. Visible light is the part of the spectrum that is seen as colors, including violet, indigo, blue, green, yellow, orange, and red. Ultraviolet radiation is invisible to the human eye but is present in sunlight and contributes roughly 10% of the output of electromagnetic radiation from the sun. Visible light accounts for 40% to 45% of sun-emitted energy that reaches the earth, and UV rays account for just 3% to 5% of the total solar spectrum but have a tremendous impact on skin. However, the remaining sun-emitted energy is infrared radiation, which accounts for 50%. In physics, electromagnetic radiation is waves of the electromagnetic field radiating through space and carrying electromagnetic radiant energy (National Aeronautics and Space Administration [NASA], n.d.). Therefore, the electromagnetic spectrum is a range of frequencies of electromagnetic radiation. Electromagnetic radiation with a wavelength between 380 and 760 nm (400 to 790 terahertz) is detected by the human eye and is perceived as visible light. (NASA, n.d.). The length of the waves is measured in nanometers (nm), with 1 nanometer equaling 1 billionth of a meter. Every wavelength is represented by a different color and is grouped into bands, beginning at the lower frequency (long wavelength) end: Radio waves, microwaves, infrared, visible light, ultraviolet (UV), X-rays, and gamma rays at the high frequency (short wavelength) end of the
BLUE LIGHT POLLUTION
Today's spa-goers are concerned about blue light–induced skin damage and digital aging. There is recent research that indicates blue light exposure can cause photodamage to the skin, leading to collagen degradation, hyperpigmentation, and oxidative stress (Coats, 2021). Blue light protection
is still in its infancy state. Indoor lighting and digital light sources such as smartphones, televisions, tablets, and computers emit more blue light than other colors of light, and these light sources can have an intensity in the 400- to 500-nm range. However, digital screens are not the only
Page 47
Book Code: ENC0826
EliteLearning.com/Cosmetology
Powered by FlippingBook