The World Health Organization defines air pollution as “contamination of the indoor or outdoor environment by chemical, physical, or biological agents that modify the natural characteristics of the atmosphere”, with 6.4 billion people expected to be exposed to elevated levels by 2050.
This essay will discuss the sources and types of air pollution, how air pollution affects the skin, anti-pollution formulation strategies and the efficacy of anti-pollution claims for skin care active ingredients.
Types of air pollution
Air pollution can be classified based on the source, with primary pollutants being formed and emitted and secondary pollutants formed when these primary pollutants react in the troposphere.
The US Environmental Protection Agency (US EPA) has defined the major air pollutants as particulate matter (PM), heavy metals (cadmium, lead, nickel, copper and arsenic, which bioaccumulate increasing toxicity through increasing concentration in tissues) and gaseous compounds (carbon monoxide [CO], nitrogen dioxide [NO2] and sulphur dioxide [SO2]).