The pollution we are going to cover in this article is Air Pollution, sometimes it is super obvious - you can see a 'smog' or smell the 'fumes' from cars; pollution effects our skin and our health and is a leading cause of premature ageing. Living in a city especially big metropolitan cities - think Melbourne, Sydney or even a Mega City like Los Angeles, London or Beijing you are exposed to far more harmful levels of pollution than that of a rural town. These environmental aggressors are contributors to: the fine lines, uneven texture and pigmentation we associate with ageing. Air pollution can lead to skin ageing and the worsening of inflammatory skin diseases like eczema, acne and psoriasis.
The Mechanism of Damage
As defined by the World Health Organization (WHO), air pollution is the "contamination of both indoor and outdoor environments by any chemical, physical, or biological agent." These environmental factors have very serious negative health effects, they are also damaging our largest organ: your skin.
"Currently, 92% of the world's population lives in places where air pollution levels exceed the limits set by the World Health Organization."
The respiratory and oral tracts along with the skin are the common routes by which organisms enter in contact with different ambient pollutants. Environmental stressors may exceed the skin’s protective potential and disturb its structure, leading to skin diseases such as erythema, hyperplasia, skin ageing, dermatitis, psoriasis and carcinogenesis. Recent epidemiological studies suggest that Particulate Matter negatively affects human skin and exacerbates pre-existent skin diseases.
Damaging effects of pollutants to the skin include:
- The appearance of enlarged pores
- Allergies, redness and detrimental to immune system
- Dark spots
- Dry skin conditions leading to eczema and psoriasis
- Premature lines and wrinkles
- Uneven skin tone
White blood cells produce free radicals from oxygen to kill bacteria or viruses, when they are exposed to air pollution, these free radicals may be created to fight off potential pollution deposits, but as the white blood cells cannot kill the pollution particles, more white blood cells come in, creating even more free radicals, causing oxidative stress and inflammation. Traffic-related air pollution has also been shown to cause the formation of lentigenes, dark spots on the skin - in women in Germany and China, with the most pronounced changes on the cheeks of Asian women over 50, according to research in the Journal of Investigative Dermatology.
A recent study in China found that indoor air pollution, due to close proximity to smokers, cooking fuels and roads, can also cause skin ageing.
Two factors cause the greatest damage Sun and Smoke - and when air particles cause free radical damage to cells, certain parts of our cells are not replaceable.
Types of Pollutants
Polycyclic Aromatic Hydrocarbons (PAHs)
- Cigarette Smoke
- Ultraviolet Radiation
- Volatile Organic Compounds (VOCs)
- Oxides - Industrial Power Plants
- Particulate Matter (PM)
Polycyclic Aromatic Hydrocarbons (PAHs)
These are organic pollutants which result from the 'burning' of an organic compound. The burning of wood, exhaust fumes [diesel being the worst offender] cigarette smoke, waste incineration, metal production, and burning fossil-fuel.
Skin Effects: PAHs induce melanocyte proliferation and cause skin pigmentation.
Contains thousands of chemical substances like carcinogens - a substance capable of causing cancer in living tissue. Oxygen radical forming substances such as catechol - a substance known to cause eczema dermatitis.
Skin Effects: Chemical substances from cigarette smoke activate trans epidermal water loss, degeneration of connective tissue, causes deeper wrinkling, premature facial skin ageing in smokers along with orange-purple skin discoloration. Free radicals from cigarette smoke are associated with oxidative stress resulting in lipid cell damage. A higher occurrence of acne among smokers and a correlation between the severity of acne and the number of smoked cigarettes has been shown also cigarette smoke is associated with psoriasis.
Ultraviolet Radiation (UV)
UV Radiation covers UVA UVB and UVC - 95% of the solar radiation that reaches the earth's surface is UVA and UVB. Most of UVC is absorbed by the Ozone layer and oxygen in the atmosphere. UVA//UVB rays, infrared, high-energy visible blue light, and particulate matter are all strands of pollution.
Skin Effects: Pollutants trigger the immune system to produce excessive melanin, which causes pigmentation, skin darkening, and inflammation, and weakens the skin's barrier, causing lines and wrinkles. UVA has been linked to skin photoaging and to the development of skin cancers. UVA penetrates deeply into the basal layer of the epidermis and dermal fibroblasts. UVB has also been linked to the development of skin cancers. UBV is largely absorbed by epidermal cellular components.
O3 exists in the stratosphere and in troposphere. Normally, O3 is found in low concentrations at ground-level, originating from the stratospheric O3 and hydrocarbons which are released by plants and soil. However, O3 may be formed as a by-product of certain human activities, with the interaction of sunlight (UVR), hydrocarbons, VOCs and NOx, representing a major active component of the pro-oxidant smog. The actions of O3 could be amplified in the presence of other air pollutants, where concomitant exposure to UV irradiation and O3 could reveal synergistic oxidative stress effects in skin.
Skin Effects: Experimental evidence shows that O3 can induce damage in the epidermis of mice skin, reduce the level of antioxidants such as a—topopherol (vitamin E) and ascorbic acid (vitamin C) and increase malondialdehyde (MDA) a lipid peroxidation product. These effects lead to barrier disruption, the production of lipid ozonation products and inflammation. The first target of O3 is the stratum corneum that contains a high level of unsaturated fatty acids and lipids, with the generation of ROS. O3 stimulation results in disturbed activity of matrix metalloproteinases (MMPs), resulting in the degradation of extracellular matrix components such as collagen and elastin, implicated in extrinsic skin ageing. Tropospheric O3 exposure has been associated with urticaria, eczema, and contact dermatitis, in a study showing the cutaneous effects of O3 by collecting data from almost 70,000 patients.
Volatile Organic Compounds (VOCs)
These are emissions from the use of organic solvents found in: paints, varnishes, environmental tobacco smoke, stored fuels, exhausts from cars and from Industrial Factories - SMOG.
Skin Effects: can cause both inflammatory reactions and allergic reactions resulting in atopic dermatitis or eczema.
Are emitted mainly from mobile and stationary combustion sources: Industrial Power Plants and exhaust fumes, also from natural sources like volcanic activity and forest fires.
Skin Effects: The generation of free radicals that may oxidize amino acids in tissue proteins and initiate lipid cell damage of polyunsaturated fatty acids, resulting in dermatitis and atopic eczema (when exposed to high levels of traffic related air pollution.)
Particulate Matter (PM)
These are air pollutants that are made up of different mixtures and sizes of particles resulting from Factories, Automobiles, Power Plants, Waste Incinerators, Fires and natural windblown dust. PM has more skin-damaging effects than any other pollutant, according to a study in Toxicological Sciences. The most health-damaging particles are those with a diameter of 10 microns or less, (≤ PM10), which can penetrate through the skin. The impact of PM2.5 on the human respiratory system has been well documented, for example by the Journal of Thoracic Disease, and these particles can lodge inside the lungs.
Skin Effects: Particles in the nanosize range, below 2.2 microns actually penetrates through the pores and causes cellular damage such as pigmentation, fine lines, inflammation, and sensitivity. Traffic sources, are considered among the most harmful components causing oxidative stress in skin meaning premature ageing - pigment spots and wrinkles.
While it is not possible to totally avoid pollution unless you do not go outs outside again! although there is pollution found inside our homes too - more of that next week when we take a look at what you can do to protect your skin from Pollution.
Be human | be kind | be you
- Potential of herbs in skin protection from ultraviolet radiation - Korać, R. R., & Khambholja, K. M. (2011). Potential of herbs in skin protection from ultraviolet radiation. Pharmacognosy Reviews, 5(10), 164–173.
- Air pollution and the skin -http://journal.frontiersin.org/article/10.3389/fenvs.2014.00011/full
World Health Organization (WHO)
Journal of Investigative Dermatology.
Indoor air pollution study:
Skin-damaging effects of PM
Journal of Thoracic Disease
Air pollution and the skin