Exploring the Air Exposome With Mass Spectrometry

Air exposomics is something that we envision as being a very impactful field as we go forward. Of course, exposomics is by no means new, but it is an emerging inter- and multidisciplinary field where we have people working in biological health sciences and people working in environmental science.

The more I’ve talked to environmental scientists, I have learned that they always orient the importance of their research by highlighting aspects that are important for human health, then they go on to write the rest of their grant or their paper. But that link to human health could be expanded on—and environmental scientists are actually very keen to link up with biological researchers and expand on the health factors underpinning their arguments.

'That is where exposmics comes in. It is really bridging that gap in studying the interface of our environment and our human health.' — Dr. Matthew Lewis.

Air exposomics is a subset of this that relates to the study of the “airborne exposome.” What does that encompass? All of the particles, all of the gases, all of the trace metals, essentially everything that you come into contact with via the air that we breathe. Humans breathe air all the time—we can’t avoid that. And that makes it a bit of a different beast compared to contaminants you might be exposed to through certain foods or water sources. We can purify those things; we can check ingredients and food contaminants in certain items. But the air that you breathe is constant. When we leave this building, we will walk down the street, and we’ll inhale car exhaust. As we sit here in these chairs, we’re touching synthetic fibers and we’re inhaling microplastics. Each of us has a personal “dust cloud.” Air exposomics is really the drive to help bridge all of these different communities, with a focus on the airborne exposome.

The main challenge really is that there is not much precedent here, especially for measuring metals in air. A lot of people don’t even know that this is an issue. When we invent and commercialize a technology such as the mipTOF, all of a sudden you are able to see what you didn’t even know you should have been seeing before.

For example, there are air monitoring programs all over the world, often in urban environments. I live in London, and I am lucky to know some of the people who run an [air quality monitoring] supersite there—Prof. Frank Kelly’s research group at Imperial College London, they run a lot of those. What exactly are they monitoring? Usually it’s particulate matter, PM 2.5 and PM 10, and maybe they are also looking at certain gases, that’s all fine and standard. But then something new shows up, like airborne metal, and they say, “Whoa, we didn’t know that this was a monitorable thing; let’s go and see.” Then you go next to a railroad track as a train goes by and yes, you can see it. So I think there is a big challenge sometimes even just in knowing which direction to go down. It’s like we’re exploring uncharted space on a map, and that’s what our customers are really excited about.

There are other technical challenges too. I could go around with a wristband that absorbed chemicals from my environment, but then when I go back to the lab to analyze it, it’s impossible to know when those exposures happened. You see the magnitude of the exposure, but was that due to low-level exposure all day long, or did I walk past one specific heavy emission source? You can’t tell the difference with systems like these.

With the high time resolution systems that TOFWERK provides, these systems are field deployable, so you can put them in vans and in airplanes, and you can drive them around to geo-spatially map your spectra to certain things. This helps you understand exactly where these things come from, and exactly what the magnitude of exposure is at a given time. Solving challenges like this really starts to make the science more tangible.