Does chronically poor air quality age your skin?

Several independent population studies link exposure to fine particulate matter, soot and nitrogen dioxide to more wrinkles and age spots. Air pollution therefore appears on the recognised list of seven risk factors for skin ageing, alongside smoking, sun exposure, age and diet. The fact that these associations appear in multiple countries and population groups makes them credible, although the precise magnitude differs from study to study.

How does this work mechanically? Pollutant particles damage the outermost layer of the skin, the protective barrier that retains moisture and keeps irritants out. At the same time, they trigger a kind of smouldering inflammation in skin cells and accelerate the ageing process at the cellular level. Dryness, redness and accelerated wrinkle formation are possible consequences. How large that contribution actually is in humans is still difficult to measure.

Ozone, the gaseous form of air pollution that forms close to the ground, also appears to contribute independently to wrinkle formation, separately from fine particulate matter and UV radiation. This area of research is still in its early stages, however; it is based on limited evidence and requires confirmation in larger studies.

Air pollution and sunlight may not simply add up in a straightforward way. Recent findings show that the effect of fine particulate matter on the skin is actually stronger at lower levels of UV exposure, suggesting that both factors interact in a complex manner. Exactly how remains unclear. Beyond ageing, air pollution is also associated with eczema, hives and acne, showing that the damage extends well beyond wrinkles alone.