Ceramide

• Also known as atopic dermatitis, this chronic skin disease affects about 1 in 5 children in the industrialized world.
• Some studies have found rates of eczema in developing nations to be over thirtyfold lower compared with industrialized nations.
• Scientists know that factors such as diets rich in processed foods as well as exposure to specific detergents and chemicals increase the risk of developing eczema.
• Living near factories, major roadways or wildfires increase the risk of developing eczema.

There’s something in the air

• Then we looked at databases from the U.S. Environmental Protection Agency to see which chemicals were most common in those areas.
• Diisocyanates were first manufactured in the U.S. around 1970 for the production of spandex, nonlatex foam, paint and polyurethane.
• The manufacture of xylene also increased around that time, alongside an increase in the production of polyester and other materials.

• After 1975, when all new cars became outfitted with a new technology that converted exhaust gas to less toxic chemicals, isocyanate and xylene both became components of automobile exhaust.
• How directly exposing mice to these toxins compares to the typical levels of exposure in people is still unclear.

Skin microbiome and pollution

• Every person is coated with millions of microorganisms that live on the skin, collectively referred to as the skin microbiome.
• You’ve probably seen moisturizers and other skin products containing ceramides, a group of lipids that play an important role in protecting the skin.

• To see which toxins could prevent production of the beneficial lipids that prevent eczema, my team and I used skin bacteria as canaries in the coal mine.
• Lysine helps protect the bacteria from the harms of the toxins but doesn’t provide the health benefits of ceramides.
• Bacteria that help keep skin healthy could live on any fabric, but, just as with air pollution, the amount of beneficial lipids they made dropped to less than half the levels made when grown on fabrics like cotton.

Addressing pollution’s effects on skin

• Detectors capable of sensing low levels of isocyanate or xylene could help track pollutants and predict eczema flare-ups across a community.
• Better detectors can also help researchers identify air filtration systems that can scrub these chemicals from the environment.
• In the meantime, improving your microbial balance may require avoiding products that limit the growth of healthy skin bacteria.
• I believe that it may one day allow us to get back to a time when these diseases were uncommon.

Ian Myles receives funding from the Department of Intramural Research at the National Institute of Allergy and Infectious Diseases. He is the author of, and receives royalties for, the book GATTACA Has Fallen: How population genetics failed the populace. Although he is the co-discoverer of Roseomonas mucosa RSM2015 for eczema, he has donated the patent to the public and has no current conflict of interest for its sales.