Air pollution: If you live in Los Angeles, it's part of the skyline; if you live anywhere else it's probably something you either don't think about or just accept as part of modern life. 

After all, smog doesn't seem to do much harm, really, aside from hanging there and blocking the view. 

Unfortunately, air pollution isn't so innocuous. Aside from environmental and health effects, it turns out that smog could actually be making us stupider. 

How pollution affects performance
A National Bureau of Economic Research study carried out in Israel found that worse pollution on the day of regularly administered high school exams reduced student performance relative to their previous examinations. 

In other words, even just a single bad day of pollution affected how well students took the test.

Unfortunately for students, having the bad luck to have several badly polluted testing days over the course of their high school career also had a small but significant effect on whether they earned matriculation certificates -- which are a prerequisite for college admission. 

It drives home the point that something you might think of as unchangeable -- your ability to get into college -- is actually subject to influence by any number of factors.

And pollution is one of those factors.

Not convinced? 
Another study looking at the effect of fetal exposure to carbon monoxide on primary school test outcomes came up with similar results. Even in the womb, carbon monoxide affects the body's ability to get oxygen from red blood cells, and the result is lower cognitive performance.

Once they discovered this, the study's authors tried to estimate the effect that Santiago, Chile's significant pollution reduction program had on kids in Santiago.

It was about $100 million in increased lifetime earnings per age group, or about $1000 per person, on average. That might not sound like much on an individual basis, but taken together that's a lot of economic activity that would have otherwise gone up in, well, a puff of smoke. .

Air quality isn't just an environmental issue
If you thought the impact of carbon monoxide and other forms of pollution are limited to kids, you'd be wrong.

The air we breathe affects adults as well. Even too much carbon dioxide (the stuff you exhale) in an office can affect your cognitive performance; one study found that gradually increasing carbon dioxide levels in a room had a significant impact on several decision-making measures in adults. 

Those results are particularly problematic when you take into account that carbon dioxide levels tend to be worse in conference rooms. Even at levels too low to show up on individual performance scores, carbon dioxide starts affecting group decision performance (a great addition to your list of reasons why you hate meetings). 

And that's just carbon dioxide. 

Emissions from cars and power plants are affecting us too, it's just harder to measure the impact in the absence of clear data. Luckily, data from academic studies like these can shine some light onto the subject.  And the unfortunate takeaway is that our air could be making us, and our children, stupider.

Whatever your thoughts on environmentalism or buying green, that's a hard conclusion to ignore. So in the absence of immediate control over pollution levels, try to take what steps you can to make your air a little better -- plants in the conference room, hosting meetings outdoors (depending on the smog), or just forgiving your kid for falling asleep in class, again.  

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