Why Low Levels of Air Pollution Actually Cause the Most Harm

The up-to-date research on the health effects of air pollution have discovered a surprising finding–low levels of air pollution are actually more harmful than higher levels. This data has potentially important implications for people living in relatively “clean” cities like New York and London.

Beijing Pollution: Why low levels of air pollution actually cause the MOST harm

 

My Intuition About Air Pollution’s Health Effects

Join me for a quick thought experiment. Let’s say you could wave a magic wand and reduce PM2.5 pollution by 5 micrograms in either Chicago (where I live)…

Chicago Pollution: Why low levels of air pollution actually cause the MOST harm

 

or Beijing (where I often go).

 

Beijing airpocalypse: Why low levels of air pollution actually cause the MOST harm

Your goal: Save the most lives possible. Where would you put your magic wand to work?

Before you decide which city to help, it is important to understand the relationship between tiny PM2.5 particles and death. Would it look like this?

This is NOT how air pollution impacts deaths

 

In this case, the idea is that air pollution hurts us little by little, but then the damage really starts to get bad at severe levels. This logic is implicit when people ask questions like, “How much saturated fat is safe?” Or “what’s a safe level of lead in my body?”

But maybe your intuition is different. Maybe pollution affects us in a linear way?

 

This is NOT how air pollution impacts deaths

 

That makes sense to me too. In that case, each step up in air pollution hurts us the same as the step before.

 

Studies Find Low Levels of Air Pollution Most Harmful

As logical as those predictions are, they are wrong. Scientists analyzed the effects of PM2.5 on death, and they found that low levels actually hurt more. So they relationship looks more like this:

 

Why low levels of air pollution actually cause the MOST harm

 

Or in the form of actual data, this is what it looks like. An increase in pollution from low levels does MORE damage than increases at higher levels.

 

Why low levels of air pollution actually cause the MOST harm

 

If that doesn’t make you poop your pants, perhaps you’re not such a stats nerd like me. But here’s why that graph is crazy.

Let’s say China has a bad year, and air pollution goes from 125 to 150 micrograms. Based on China’s population, that would mean 60,000 more people will die.

 

Why low levels of air pollution actually cause the MOST harm

That’s a lot of people, probably more than have died on “The Walking Dead.”

But that same increase—25 micrograms—would kill almost twice as many people (per capita) if it happened in China’s cleanest major city, Shenzhen.

 

Why low levels of air pollution actually cause the MOST harm

Why would low levels matter more?

Here’s a metaphor: imagine getting hit by a baseball bat.

Why low levels of air pollution actually cause the MOST harm

That first hit would hurt a lot—probably break some bones. But what about the fifth strike? The tenth strike? A lot of the damage has already been done, so the tenth strike doesn’t add much. (Sorry for the gruesome metaphor!)

Two Reasons Why This All Matters

Besides being a surprising finding, this data has two real-world implications.

1. The most important progress is still ahead

I lived through a year of Beijing smog when the average was over 100 micrograms. In 2018, Beijing averaged about 50 micrograms.

 

Why low levels of Beijing air pollution actually cause the MOST harm

 

That’s amazing progress! Beijing cut its PM2.5 by an astounding 50 micrograms.

 

Beijing Air Pollution: Why low levels of air pollution actually cause the MOST harm

But because of the baseball bat principle, Beijing would save more lives if they improved from here. Oddly enough, improvement becomes more valuable once things are pretty clean.

2. If you’re in a “safe” city like I am, you should be worried

For my day-job, I live in Chicago. When I see graphs like this, I feel pretty good about myself. I feel safe.

 

Even "Clean" Cities Have an Air Pollution Problem

 

But the new studies on health effects at low levels of pollution have changed the way I think about safe air. The baseball bat principle could explain why recent studies have been finding meaningful health effects on blood pressure and diabetes.

 

Even Low Levels of Air Pollution Are Problematic

Data has even found meaningful effects comparing 12 micrograms to 7 micrograms. Less is better.

Bottom Line: Low levels of pollution are a problem

Pollution isn’t just a Delhi or Beijing problem. People in “clean” cities like where I live should be worried too.

Breathe safe!

Why low levels of air pollution actually cause the MOST harm

P.S. As scary as that data is, the data on the effectiveness on purifiers and masks is scary good. I cover that data and the three simple, low-cost things I do that drastically reduce the amount of pollution I breathe when I’m in Beijing and Delhi.

How I Protect Myself

Smart Air is a certified B Corp committed to combating the myths big companies use to inflate the price of clean air.

Smart Air provides empirically backed, no-nonsense purifiers and masks, that remove the same particles as the big companies for a fraction of the cost. Only corporations benefit when clean air is a luxury.

Check out the Sqair!

Sqair Air Purifier

 


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Smart Air is a social enterprise that creates simple, no-nonsense air purifier and provides free education to protect people’s health from the effects of air pollution. We are proud to be the only certified B-Corp dedicated to fighting air pollution.