Unstable 'Ingredient' Discovered in Earth's Atmospheric 'Cocktail' May Affect Life on Our Planet

When we speak of Earth's atmosphere, commonly known as air, we refer to a layer of gases retained by our planet’s gravity, surrounding it and protecting all existing life on it. Although oxygen is crucial for life on Earth, it is not the primary component of our atmosphere.

The air “mix” that we breathe on planet Earth is made up of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases. But there is also a generous helping of different compounds and elements, with one of these “ingredients” thrown into focus by new research.

Dutch chemists have discovered that a reactive, or “unstable” class of compound called organic hydrotrioxides exists in the atmosphere. Despite their brief existence, the chemicals could have an effect on life on Earth that we know hardly anything about, research published in Science on 26 May said.

"These compounds have always been around - we just didn't know about them," chemist Henrik Grum Kjærgaard from the University of Copenhagen, Denmark, was cited by media outlets as saying, adding:

"But the fact that we now have evidence that the compounds are formed and live for a certain amount of time means that it is possible to study their effect ... and respond if they turn out to be dangerous."

As hydrotrioxides are highly reactive, scientists have been speculating on whether they can form stable structures in the atmosphere. The interest was far from exclusively academic, as a great deal of how our atmosphere operates, including its effect of human health, depends on how trace materials in it interact.

"Most human activity leads to emissions of chemical substances into the atmosphere. So, knowledge of the reactions that determine atmospheric chemistry is important if we are to be able to predict how our actions will affect the atmosphere in the future," Kristan Møller, a chemist from the University of Copenhagen, added.

The team's investigations have offered the first direct observations of hydrotrioxide forming in the atmosphere from several substances present in our air. The study observed how the compound was synthesised, how long it lasts in the air we breathe, and how it degrades.

For example, it was revealed that a common organic compound called isoprene can react in the atmosphere to generate around 10 million metric tons of hydrotrioxide annually. And that is only one possible source of the chemical.

The research team’s calculations suggest that any compound could potentially play a role in the atmospheric formation of hydrotrioxides, with the latter remaining intact for between a few minutes to a few hours. Throughout that period, the hydrotrioxides can perform the role of a powerful oxidant in various other reactions.

"It is easy to imagine that new substances are formed in the aerosols that are harmful if inhaled. But further investigation is required to assess these potential health effects," said Kjærgaard.

Subsequent research can be expected to shed further light on the role of hydrotrioxides in our planet's atmosphere.

"Indeed, the air surrounding us is a huge tangle of complex chemical reactions. As researchers, we need to keep an open mind if we want to get better at finding solutions," University of Copenhagen researcher Jing Chen said.