How do you sum up the relationship between our skin, pollution, and our health? Well, consider this: skin is our largest organ. It is the barrier that protects us. It protects us from pathogens, from the sun, and from extremes in temperature. Also, these days, it increasingly protects us from pollution. So, protecting our skin is becoming more and more important… after all, every single day, whether you live in a city or not we all exposed to forms of pollution. And it can travel long distances, be in the air, the soil, the water you drink or the food you eat. Even at high concentrations. So, how does our environment affect our skin? There are many ways our environment affects our health. The climate, the water we drink and the chemicals we encounter in our daily lives all play a part. Newly created substances (like nanoparticles) can also now transport toxins deeper into skin – acting as “carriers”, taking contaminants further into the skin. A recent study by Scientist Yin-mao Dong and colleagues in Chinai highlighted how these environmental factors affect our skin – they found that polluted city air with high levels of particulates (PM) caused the following: skin inflammation and inflammatory skin diseases such as atopic dermatitis, acne and eczema. They also found a link to premature skin aging caused by oxidative stress or “programmed cell death”. If temperatures rise due to global warming, the way pollutants affect the human body may change again. For example, the skin may have to produce more sweat, react to dustier and dirtier air, cope with more indoor living in which air conditioning is more common, or less access to pure, clean water. The way the skin reacts Pollutants entering via the skin increase the generation of reactive oxygen species (ROS), leading to a rise in free radicals. This can lead to a weakening of the skin barrier – our principal line of defence. Oxidative stress, an over-production of reactive oxygen species (ROS), means the body’s natural antioxidant network can’t neutralize all the ROS before they do damage to skin and other organs. One of the consequences can be melanogenesis, a condition resulting from DNA damage (for example due to overexposure to the sun). Collagen reduction can also occur due to the activation of metalloproteases. Also, there can be alterations to cell cycles, decreased reserves of antioxidants and the activation of inflammatory pathways. All these effects can be triggered by environmental factors such as increases in UV and pollution. Other consequences of environmental change are hyperpigmentation and increases in the signs of aging. This can affect our mental health as it hits at our complexion and self-esteem. Individuals are affected differently; it depends on age, degrees of sun exposure, skin sensitivity and many other factors, such as lifestyle and occupation. But in everyone, pollutants increase these levels of free radicals in the body, damaging cell DNA molecules and causing a potential malfunction of the epidermal barrier. It can lead to poor formation of collagen - the elastin fibers that make up the skin. Consequently, skin can become less firm, less elastic, and in turn, “older” looking. Contamination affects the skin on all levels The skin is not smooth, and the effect of pollution is not skin-deep. The epidermis is full of pores, hair follicles and sebaceous and sweat glands. These are the possible "contaminant entry gates" where harmful particles settle, and where they can be carried further into the human body. Sweat together with the ambient dirt, causes particles to stick to the skin, forming a "goo”. Pores can then clog, preventing oxygenation and healthy functioning of the skin. For example, it can prevent dead cells from clearing, slowing down the speed of cell renewal. Internal effects stem from the fact that dirty skin loses its ability to “exchange” with the outside world, causing it to "deactivate”. This reduces the supply of blood to the skin and its ability to“cleanse” our bodies. What can we do to protect our skin? It is impossible to completely avoid contaminants and most of us in fact have continuous contact with contaminants, both physical, biological and chemical (like toxic gases). The skin is our barrier and is profoundly affected by these environmental changes. We can suffer skin inflammation and dehydration, activating the immune response, and increasing the speed of skin aging. The result can be dry skin, more wrinkles and spots, eczema, allergic problems, and irritation. We should regularly remove contaminants that are deposited on the skin, limiting the formation of free radicals. Cleansing skin is essential, as is the careful choice of soaps, cosmetics and cleansers. Cleansing your skin to safely rid it of grime, chemicals, and toxins. It is important to moisturize the skin, avoid too much sun and eat foods rich in antioxidants. Also, and very important, is to (wherever possible) avoid exposure to high levels of pollution. Your skin health is now known by scientists to be intrinsically linked with your overall health, so take care of it… after all, day in day out it takes care of you!