Newsletter #251

Hey y'all, this week I thought we'd take a look at a couple of recently published studies examining the effect of indoor air quality on cognition, a topic that we have touched on a bit in the past.

One of the silver linings of the pandemic is that it has brought the issue of clean air to the forefront, and has elicited public discussion of possible long-term payoffs of improving ventilation in the buildings we spend most of our time in.

That dialogue, of course, is mostly oriented around reducing transmission of infectious diseases. But some preliminary evidence suggests that improving air quality by removing common indoor pollutants, like volatile organic compounds and fine particulate matter, could also improve our thinking and productivity.

For example, a study that looked at more than three hundred healthy office workers in 43 different commercial buildings found that higher concentrations of fine particulate matter in their workspaces were associated with slower response times and reduced accuracy in cognitive tests that were administered while they were at work. Importantly, these effects were evident at levels that are commonly observed in indoor environments.

The two studies that I’ll be digging into today examine effects of indoor air pollutants on expert chess players and on schoolchildren. But before I go there, I wanna remind y’all about the coaching program that we are set to launch soon (super exciting!). If you’d like to be the first to know when that ship embarks, please head to this link and fill out the short form (only takes like 30 seconds). We will notify you with any key updates. 👀

Much attention is given to the perils of outdoor air pollution, like what emanates from automobiles and factories. However, we now know that levels of particulate matter in indoor environments can actually be higher than outside. Given the aforementioned impact of these airborne particles on cognition, scientists and policymakers have wondered about how indoor air quality can influence student performance. To examine whether air purification in schools could improve academic performance, a researcher cleverly took advantage of a natural experiment. A few years ago, a massive gas leak was discovered in the San Fernando Valley, affecting a wealthy Los Angeles neighborhood that normally has relatively clean air. In response to public pressure, the local school district installed air filters in every classroom, office, and common area in all schools within five miles of the gas leak at the end of January 2016. The researcher chose to compare academic outcomes for students attending schools just barely within the five-mile boundary of the gas leak (who received air filters) to those who were just outside (thus no filters), since these schools were likely to be otherwise pretty similar to one another. Indoor quality tests, performed before and after the air filters were installed, revealed that the filters were indeed lowering levels of indoor pollutants. Methane levels dropped by 17%, and levels of various volatile organic compounds fell by 60-100%. After adjusting for student demographic variables, he found that air filters raised math scores on average by 0.20 standard deviations, and English scores by 0.18 standard deviations (the latter was not statistically significant). But here's what makes this finding compelling. The gas leak kind of turned out to be a false alarm, at least from the schools' standpoint. By the time the air filters were installed, any pollution associated with the natural gas had apparently already dissipated. In other words, these air filters were not mitigating a disastrous rise in air pollution, but were merely remediating the typical levels of indoor pollutants occurring in these schools, making the findings more generalizable. As author Michael Gilraine says, "Natural gas was not detected inside schools, implying that the filters improved air quality by removing common pollutants and so these results should extend to other settings."

It has been thought for some time that acute exposure to air pollution might affect cognitive control. For example, an analysis of readings of ambient air pollution and records of criminal offenses in London found that a rise in the local Air Quality Index was associated with an increase in the crime rate. To examine how changes in indoor air could influence decision-making, researchers analyzed a data set of move decisions made by chess players and the readings of indoor air quality monitors that had been installed inside tournament venues. The data contained more than 30,000 moves from 121 players in three official tournaments held in Germany. Each move was objectively evaluated by an AI–based chess engine, a program that analyzes chess positions and generates a move or list of moves that are deemed to be strongest. When the researchers looked at the air quality readings, they determined that an increase in fine particulate matter of 10 micrograms per cubic meter led to a 2.1 percentage point increase in the probability of making a meaningful error, or a 26.3% increase relative to the average proportion of errors in the sample. Notably, players who were under greater time pressure seemed to be more strongly affected by surrounding air quality, suggesting that this finding may be even more relevant for those engaged in tasks or professions in which decisions need to be made quickly. Indeed, it has been shown that investors made worse stock trading decisions on hazy days.

Getting more forgetful over time seems to be a natural part of life. As we get older, we tend to remember less and less of our daily lives. But when is that a cause for concern? And could sometimes what we perceive as "forgetfulness" be a feature, rather than a bug?

Those questions are explored in the following article and podcast from our friends over at Brainjo:

There isn’t a whole lot that you can do individually about outdoor air pollution other than stay inside when levels of pollutants are high (or move somewhere with cleaner air I guess?).

But the indoor environment has its own perils. Indeed, the EPA has estimated that concentrations of certain recognized air pollutants can be 2-5 times higher in indoor environments than outdoors, due to compromised dilution capacity in enclosed spaces. And fortunately, indoor air is much more actionable.

In this How-to Guide, we identify the main types of indoor air pollutants and go over what you can do to mitigate or eliminate them, as well as some fact-checking on a very popular (but scientifically dubious) method for purifying indoor air.

This is obviously a relevant concern for those of us who work in offices most of the day, but it's also key if you're a member of the WFH brigade. One recent study that installed air monitors in the homes of people working remotely during the pandemic found that fine particulate matter levels in the homes of every single participant exceeded air quality standards established by the EPA for a healthy work environment.

That's why we created this guide. It will show you how to test indoor air quality, and support maintenance of better air quality in your indoor spaces, for a healthier body and sharper mind.

https://mailchi.mp/humanos.me/newsletter-251