Every puff of air we take in is mostly nitrogen, with a generous helping of oxygen and a pinch of carbon dioxide.
But dusting this atmospheric soup is a whole encyclopedia of different compounds and elements, some of which we can only speculate on.
However, one of these mysteries has just been unraveled. Chemists have shown that a reactive class of compounds called organic hydrotrioxides exist in the atmosphere, and while these chemicals last only briefly, they could have effects we don’t know about.
In fact, according to the researchers’ calculations, you just sucked up a few billion molecules of it by reading this.
What exactly this means for your health, let alone the health of our planet, is literally and figuratively up in the air. But given that we’ve just discovered this new ingredient in Earth’s atmosphere, it’s worth looking into.
“These compounds have always existed – we just didn’t know about them,” says chemist Henrik Grum Kjærgaard from the University of Copenhagen in Denmark.
“But the fact that we now have evidence that the compounds form and live for a period of time means that it is possible to study their effect…and to react if they turn out to be dangerous.”
Very often in chemistry, the addition of a single new component can radically change the behavior of a material.
Take water, for example. Through the way its pair of hydrogens and its unique oxygen interact, organic chemistry can mix and swirl into an evolutionary phenomenon we call life.
Add just one more oxygen, however, and we get hydrogen peroxide – a much more reactive compound that can tear apart living chemistry.
Stick another oxygen on that angry little molecule, and the result is hydrotrioxide. To make it, you just need the right kind of lab equipment, some saturated organic compounds, and dry ice.
It’s not exactly the kind of party trick you’d use to spice up a margarita, but chemists have used their making to generate a specific molecular oxygen flavor as a step in the production of various other substances.
Being highly reactive, there has been an open question as to whether hydrotrioxides can easily form stable structures in the atmosphere.
It’s not just a point of academic speculation either. Much of how our atmosphere works, the complex ways it influences personal health on the massive scale of the global climate, emerges from how the trace materials it contains interact.
“Most human activities lead to the emission of chemicals into the atmosphere. Thus, 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 at future,” says Kristan H. Møller, also a chemist at the University of Copenhagen.
The team’s research now provides the first direct observations of hydrotrioxide formation under atmospheric conditions from several substances known to be present in our air.
This allowed them to study how the compound is likely to be synthesized, how long it stays and how it degrades.
One of these emissions, called isoprene, can react in the atmosphere to generate about 10 million metric tons of hydrotrioxide each year.
That’s just one potential source, though. According to the team’s calculations, just about any compound could theoretically play a role in the atmospheric formation of hydrotrioxides, which remain intact for minutes to hours.
Meanwhile, they can take part in a host of other reactions as a powerful oxidant, some of which might be housed inside microscopic solids drifting on the winds.
“It’s easy to imagine new substances forming in the aerosols that are harmful if inhaled. But further investigation is needed to address these potential health effects,” says Kjærgaard.
Since aerosols also affect how our planet reflects sunlight, knowing how their internal chemistry causes them to grow or degrade could change the way we model our climate.
Further investigations will no doubt begin to unravel the role that hydrotrioxides play in our planet’s atmospheric cocktail. As Jing Chen, a researcher at the University of Copenhagen, notes, this is really just the beginning.
“Indeed, the air around us is a huge tangle of complex chemical reactions,” Chen says.
“As researchers, we need to keep an open mind if we want to improve at finding solutions.”
This research is published in Science.