In this blog, we discuss the effects of air quality on the skin. Furthermore, we discuss the various pollutant species that are linked with damages to the skin.
Does air quality affect skin
Poor air quality can harm the skin. Skin is the largest organ of the body, and serves many important functions, such as regulation of the body temperature, and acts as the first line of defense to various toxins, and much more.
Air quality is the measure of cleanliness of the ambient air. The lower the quantity of pollutants in the ambient air, the better the air quality, and vice versa.
What does research suggest?
Over the past decades, the degradation of air quality, particularly in large cities, has been shown to affect the skin. In many studies, links between air pollution and various ailments of the skin, which include atopic eczema, cancer, and so on, have been identified.
There are many pollutants, which are generated from natural processes, as well as anthropogenic activities, that are linked with skin ailments. Some of these are
- Ozone (O3)
- Particulate matter (PM)
- Volatile Organic Compounds (VOCs)
- Polycyclic aromatic hydrocarbons (PAHs)
- Nitrogen Dioxide (NO2)
- Carbon monoxide (CO)
We shall elaborate on each of the abovementioned pollutants below.
Ozone is a highly reactive gaseous molecule which is naturally present in the upper layers of the atmosphere, where it absorbs the sun’s damaging ultraviolet radiation.
When present in the lower levels of the atmosphere, however, it acts as a pollutant, and can have serious adverse effects on human health, which also includes afflictions of the skin.
A study by Xu et al which involved 70,000 patients found an association between near surface ozone and skin afflictions such as urticaria, eczema, and contact dermatitis.
Certain studies found out that ozone disturbs the normal functioning of a certain class of biomolecules known as matrix metalloproteinases, which are associated with the breakdown of collagen and elastin, the proteins that act as building blocks of the skin.
This finding shows a clear link between exposure to elevated levels of near surface ozone to extrinsic skin aging.
Particulate matter (PM)
Particulate matter refers to a certain class of air pollutants that comprise particles in the sub-micron range with varying chemical compositions that are suspended in the air.
There are two forms of particulate matter: coarse particulate matter (PM10) and tiny particulate matter (PM2.5). PM2.5 is a prevalent problem among them.
There are many sources of PM in the ambient air. Some of the main sources include factories, power plants, refuse incinerators, fumes from automobiles, construction activities, fires and natural windblown dust.
A study by Veirkotter et al. found that Nanoparticles, particularly those from traffic sources, are among the most hazardous components of ambient PM.
This is because their physical features make them extremely reactive to biological surfaces and structures and cause oxidative stress in human skin, which contributes to extrinsic skin aging.
Another outcome of the study was that it found a link between traffic particles and soot pollution exposure with extrinsic skin aging signs such pigment spots on the face, nasolabial folds, and wrinkles.
Volatile Organic Compounds (VOCs)
VOCs refer to a variety of organic compounds that are emitted from certain materials in the form of a gas. These compounds are present in items commonly stored in houses, such as paints, solvents, cleaning products, cosmetics, and fuels.
Other sources of VOCs include vehicle refinishing products in repairing car paint, environmental tobacco smoke, stored fuels, exhaust from cars (e.g., benzene) and from emissions from industrial facilities.
A study by Ushio et al found that exposure to VOCs raises cytokines in cultured keratinocytes, which may encourage the development of inflammatory and/or allergic reactions such as atopic dermatitis or eczema.
A study carried out on mice by Michielson et al showed that exposure to hexachlorobenzene, a type of VOC, caused the formation of precancerous skin lesions.
Polycyclic aromatic hydrocarbons (PAHs)
PAHs are one of the most widespread organic pollutants. They are produced by residual wood burning, automobile exhaust fumes, particularly from diesel engines, and in all smoke resulting from the combustion of organic material, including cigarette smoke.
Studies have shown that even in the absence of ultraviolet radiation (UVR), PAHs can induce the proliferation of melanocytes, which are cells that produce melanin, which causes pigmentation of the skin, which is commonly known as tanning.
Another study showed that long term exposure of skin to elevated levels of PAHs in the ambient air causes oxidative stress of the skin and accelerates aging of the skin.
Studies have also shown that exposure to PAHs can cause an eruption of acne, in the form of comedones and cysts in the face and neck region.
Several studies have also shown that PAHs have been implicated in the development of skin cancer. PAHs that have been activated form epoxides and diols, which bind to DNA and cause cutaneous carcinogenesis.
Nitrogen Dioxide (NO2)
Nitrogen dioxide is a gaseous chemical that is a part of the nitrous oxide (NOx) species, which refers to various compounds that contain nitrogen and oxygen atoms in varying numbers.
It is predominantly produced by anthropogenic activities such as vehicle exhaust, industrial chimney emissions, and firewood burning.
NO2 is known to cause oxidative damage resulting in the generation of free radicals that may oxidize amino acids in tissue proteins.
Studies have shown that flexural eczema in middle-school students was associated with traffic-related air pollutants, which also include NOx species, with NO2 being the dominant species.
Sulphur dioxide (SO2)
Sulphur dioxide is a major air pollutant, Naturally, it is produced from volcanoes, but it is mainly an anthropogenic pollutant, produced by emissions from vehicles, particularly diesel vehicles and ships, and industrial emissions.
An East–West German comparative study showed that the prevalence of atopic eczema was higher in East Germany, which had a prevalent sulfurous type pollution.
Carbon monoxide (CO)
Carbon monoxide is a serious air pollutant, and in higher concentrations, it can prove to be lethal. Carbon monoxide is a colourless, odorless gas, therefore cannot be detected by human senses.
Carbon monoxide is formed from incomplete combustion of fossil fuels and wood. It is also formed from smoking cigarettes.
Carbon monoxide forms a strong bond with haemoglobin, the compound present in red blood cells (RBCs), which is responsible for transportation of oxygen from the lungs to the tissues, and carbon dioxide from the tissues back to the lungs.
Studies on smokers have shown a reduced amount of oxygen delivery to various parts of the skin. This causes premature aging and oxidative stress of the skin.
Sources of pollutants that affect skin
So far, we’ve discussed the types of pollutants that are responsible for adverse effects on the skin under conditions of poor air quality.
These pollutants can originate from many sources. However, there are few major sources that account for the majority of emissions of these pollutant species, which include
- Industrial emissions
- Solid fuel combustion
- Cigarette smoke
We will describe these in more detail below.
Traffic is one of the worst sources of air pollution. With time, the rise in the number of automobiles and increased incidences of traffic congestion have caused the problem to worsen even further.
Traffic-related pollution includes gaseous and particulate emissions from exhausts of the vehicles, such as nitrous oxides, sulphur dioxide, carbon monoxide, VOCs, PAHs, and PM.
Some of these pollutants react with each other under favourable conditions, and give rise to secondary pollutants such as ozone, nitrogen dioxide, and so on.
There have been many studies that have linked the effects of exposure to traffic-related air pollution (TRAP) on various systems of our body, with a substantial amount of them documenting the effects on skin.
In industrial areas, the air quality is much worse than compared to other places. The main contributors are steel and iron manufacturing plants, CTPPs, brick kilns, chemical manufacturing plants, and so on.
The majority of emissions from industries are composed of PM, SO2, NOx species, and even carbon monoxide. Workers in such industries often present various skin ailments related to poor air quality, such as eczema, rashes, acne, and so on.
Solid fuel combustion
Globally, around 2-3 billion people rely on solid fuels as the primary source of energy. This includes firewood, crop residues, and cow dung.
However, combustion of solid fuels releases a high amount of soot, carbon monoxide, and formaldehyde. This is due to the poor combustion setup, which causes inefficient burning of these materials.
Many people, particularly women and children, suffer from skin ailments caused due to exposure to pollutants generated from solid fuel combustion.
These problems get more pronounced under factors such as ventilation, duration of exposure, concentration of pollutants, and so on.
Cigarette smoke is highly complex in nature, as it is composed of thousands of chemical substances, some of which include reactive oxygen species (ROS), reactive nitrogen species and electrophilic aldehydes.
Cigarette smoke contains carcinogens, which are chemical species that can cause cancer. Studies have shown that heavy cigarette smokers were more than 4 times more likely to have facial wrinkles than non-smokers, independent of sun exposure.
Smoke-derived reactive oxidants and free radicals are linked to oxidative stress and subsequent oxidative processes. Other skin problems, such as acne and pigmentation were also observed to be higher amongst regular smokers.
Studies have also shown that cigarette smoke is associated with psoriasis, an immunological problem in which skin cells build up and form scales and itchy, dry patches.
Other FAQs about Air Quality that you may be interested in.
Exposure to poor air quality can adversely affect the skin. Studies have shown how short term and long term exposure to various pollutants affect the skin. Lastly, the various sources of pollutants that affect the skin were discussed.
How to protect skin from poor air quality?
In order to protect your skin from the harmful effect of poor air quality, you should do the following.
- Hydrate yourself, as it helps to flush out toxins that have entered the skin.
- Take a bath as soon as you come home from a polluted region, as the longer the pollutants reside on your skin, the more serious altercations you can have.
- Use a moisturizer when going out, as dry skin will be more vulnerable to poor air quality. Your family doctor or a dermatologist can help you to find the right type of moisturizer for your skin.
Are skin damages from air pollution permanent?
In most of the cases, skin damages from air pollution are not permanent. Some of the effects of air pollution on skin are pigmentation, acne, drying of the skin, itchy rashes, and so on.
However, in some cases, there are serious altercations from exposure to pollutants. These can include issues like formation of melanoma i.e., skin cancer.
Therefore, care should be taken when stepping out into a polluted environment.
Can indoor air also harm skin?
Yes, indoor air can also harm skin. Indoor air is vulnerable to pollution from indoor sources, as well as from outdoor pollution that can enter the house from windows and doors.
Therefore, it is important to maintain good air quality inside the house as well in order to prevent any damages to the skin.
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