Scientists discuss our current understanding of the links between ultraviolet radiation, air pollution, and skin cancer development, as well as potential methods of prevention.
The skin is the largest organ in the human body, however, whether air pollution can cause skin cancer development is poorly understood. The link between ultraviolet (UV) radiation and skin cancer is better known, but descriptions of how different wavelengths of UV radiation affect the skin is also inadequately described in the scientific literature.
A review by Zegarska et al., published in Advances in Dermatology and Allergology discusses what we currently know about UV radiation, air pollution, and skin cancer. The World Health Organization believes particulate matter (PM) ranging from 2.5μm (fine) to 10μm (coarse) in diameter is the most hazardous to human health. These types of particles are steadily released into the air from industrial and agricultural sources and road traffic emissions.
Polycyclic aromatic hydrocarbons (PAHs) are another type of air pollution, stemming from incomplete combustion of coal, tobacco, diesel, asphalt, creosote, gasoline, wood, oil, and tar. Previous studies link PM and PAH pollution with the development of skin cancer.
PAHs in air pollution damage DNA in the epithelial layer of the skin and are linked to the formation of squamous cell carcinomas. Particulate matter accelerates the aging process of the skin and inhibits cytochrome P450 genes, genes that play a key role in the breakdown of foreign chemical substances such as PAHs.
UVA and UVB radiation also cause oxidative and cellular damage to the skin, which increases the risk of skin cancer.
However, without analyzing epidemiological and environmental data together with national cancer reports, it is difficult to identify any specific air pollutant as the cause of skin cancer. Nonetheless, current skin cancer prevention strategies include physical and chemical skin protectants, such as titanium dioxide, zinc oxide, or helioplex, common ingredients in sunscreen.
Eating a diet rich in antioxidants (vitamins A, C, and E, β-carotene) may also boost the skin’s production of melanin to protect against UV radiation. Future prevention strategies may focus on the development of innovative sunscreens and cosmetics with SPF filters. Dermatologists are investigating the use of nanoparticles, liposomes, and nanoemulsions for new sunscreens. Other solutions may focus on education and increased awareness of the causes of skin cancer.
Our understanding of the relationship between air pollution and skin cancer is constantly improving, along with our knowledge about UV radiation-air pollutant interactions. New types of sunscreen could greatly improve skin cancer prevention, but much more research is needed.
Written By: Cindi A. Hoover, PhD