Anti-pollution cosmetic ingredients Environmental pollutants and their cutaneous impact

According to the World Health Organization, air pollution is the contamination of the outdoor or indoor environment by a chemical, biological or physical agent that alters the natural characteristics of the atmosphere. Studies have shown that our indoor environment is 2 to 5 times more polluted than the outdoor environment.

Air pollution is a global public health problem, and information campaigns and restrictions have made consumers more aware of its deleterious impact on the environment, as well as its adverse effects on human health: exposure to pollutants can either aggravate existing health problems, or generate new ones. Forecasts indicate that almost 70% of the world's population will be living in urban areas by 2050. The combination of stress and pollution linked to an increasingly urban lifestyle accentuates skin ageing. Indeed, the skin, a veritable barrier between the body and the external environment, is directly exposed to numerous environmental stress factors of both natural and man-made origin, leading to cellular oxidation, dehydration, loss of tone, increased skin spots, clogged pores, a dull complexion, the appearance of wrinkles, and so on. Consumers' heightened awareness of the effects of pollution on their skin is stimulating demand for adapted cosmetic products to counteract the harmful effects of these pollutants. As a result, new growth prospects are opening up in the cosmetics sector, and the trend for cosmetics stamped "anti-pollution" that emerged in Asia-Pacific in the years 2005-2010, has gained international momentum since 2016, when anti-pollution skincare became a category in its own right on cosmetics shelves. More and more products are being launched to protect the skin from the harmful effects of atmospheric pollution, despite the absence of standardized tests to attest to the real effectiveness of these products, or even to standardize it with, for example, the introduction of a universal anti-pollution index displayed on packaging, modelled on the sun protection factor or SPF. The aim of this article is to identify the environmental pollutants that have a real impact on skin appearance, and to pinpoint their mechanisms of action. A review of the in vitro, ex vivo and in vivo tests used to attest the anti-pollution capacities of a cosmetic ingredient, whether natural or synthetic, is the subject of the article [J 3 007] .