Humans Generate an 'Oxidation Field', And It Changes The Air Chemistry Around Us

The air around us is polluted. Ozone and water vapor can be washed away by the falling rain.

What is going on inside?

A new study shows that there's oxidation going on inside too, and that it happens through a combination of ozone leaking in from the outside and oxidation.

Scientists have found that levels of OH radicals indoors are comparable to levels outdoors. We're walking, breathing, chemical reaction machines, which have implications for indoor air quality and human health.

The Institute of Atmospheric Sciences and Climate in Italy was surprised by the discovery that humans are capable of transforming their own chemicals.

The team carried out experiments with three different groups of people in a special climate-controlled chamber with levels of ozone that matched the upper end of what you would typically find indoors. The records were made before and after humans entered the room.

It became clear through a combination of computational fluid dynamics modeling and actual air measurements that OH radicals were present and forming around the human beings.

Our personal oxidation fields are created when ozone reacts to the oils and fats on our skin, particularly on the unsaturated triterpene squalene compound, which protects the skin and keeps it supple.

The strength and shape of the oxidation field is determined by how much ozone is present, where it enters, and how the indoor space is configured.

It's thought that we spend around ninety percent of our time indoors, and these findings have important implications for making sure that time is spent breathing air that's as clean and as healthy for us as possible.

We knew that oxidation processes were happening indoors, but we didn't know that the reactions generated by humans were the ones that dominated.

It's important to understand these processes, both in isolation and in relation to other indoor chemicals that might arise from building materials, furnishings, and scented products.

The scientists want to understand how humidity levels affect the reactions and how more and more people inside a room might change that.

There is a chance that the oxidation fields humans produce could affect our perception of smell.

Jonathan Williams is an atmospheric chemist from the Max Planck Institute for Chemistry in Germany.

The research has appeared in a journal.