20. Back on the Air

It's been a while. It's still polluted.

Firstly, I’ll put it right out front: I have been on a bit of a writing hiatus. With the millions of things we all have going on, things get lost. But there is still so much to share.

Summer is approaching in the Northern hemisphere, and that means air pollution events. And man, what a start we’re off to.

Fires again.

For those in the northeastern US, you surely know we are being blanketed by an impressive swarm of forest fire emissions. Most of these originate in northern Quebec, but none of the fires are really viewed as ginormous fires (that’s the technical term, or so I’m told). Rather, there are a few hundred small-ish forest fires that are putting out hundreds of tons of particles, which are lingering in the air at relatively low altitude. This is pretty unusual.

To me, forest fires in Quebec, in early June, that have really important impacts on population centers of North America have the clear and distinct fingerprint of what we will expect with a changing climate. For those of us who have lived in the same regions of the country for decades, we can all see the hallmarks of these changes. And it seems to be getting worse.

How does this stuff get here?

Yesterday it was New York City. Today it is Philadelphia and Washington DC. Why the significant change in impact, but only a few hundred mile difference? These forest fire emissions are being transported south by persistent winds, which are caused by a weather system off of Nova Scotia. And this is the bugger sending emissions across the eastern US where ever it wishes.

A firehose of pollution, showing the Philadelphia and Washington DC areas most impacted by forest fire emissions today. Map from US EPA Fire and Smoke Map product, retrieved on June 8, 2023.

We usually think of air pollution to be regional or urban, where there are loads of pollutants in a city or region, and the concentrations become lower as you move away from the city or region. This is often not true for forest fires, which should be viewed more like a pollution-spewing factory, instead of a giant pollution-spewing region that merges into other nearby regions (think: Boston to New York to Philadelphia to Washington DC). So the pollutants from these fires move into the air and are transported by winds which shift in direction, speed, and altitude. A wind shift in a big city doesn’t change how much pollution you might see because there are so many other sources all within that same city - big highways, industrial areas, restaurants, refineries, etc.

So instead of thinking of pollution as a giant blob of stuff (like you might with a large city), it’s better to think of forest emissions more like a fire hose, where it sprays in very specific directions, and occasionally that hose direction changes. And right now, that hose is aiming right towards Washington DC.

Good data, bad data, and nonsense.

It’s important to remember that there is a lot of junk data out there.

I tend to use the EPA Fire and Smoke Map application, which is freely available. It gives you five key pieces of information: little fire icons that indicate where forest fires are occurring, an indicator in semi-transparent grey of where smoke plumes are spreading across the US (usually at different altitudes); concentrations of pollution at EPA-operated monitors (in circles); concentrations of pollution at a network of lower cost monitors (in squares); and finally, the estimated air quality index as a color. Reds to maroon = bad. Greens = good.

But a word of caution: when you zoom in on that map to your neighborhood, it’s more likely you’ll find a lower cost monitor than an EPA monitor (low cost monitors are $200-300; EPA monitors are closer $25,000). To not much surprise, those lower cost monitors are less accurate than the pricier EPA ones. Sometimes they malfunction and this goes undetected by its operator. Or sometimes they are poorly located and just report wrong data. It’s not that these are useless devices - but we are more skeptical of the data they produce.

That said, these monitors are generally pretty good, and I usually trust them to be generally correct. That’s sometimes not true of other monitoring networks, especially of well-meaning networks that might not have the buy-in from government agencies like the EPA or state governments.

Map as of 6/8/23 showing PM2.5 concentrations in greater Washington DC. Note the extremely pollution conditions uniform across the region except at some locations in Fairfax, VA, Bethesda, MD, and in the Navy Yard. These are likely malfunctioning sensors (or maybe placed indoors instead of outdoors). Map courtesy of Purple Air.

What can I do?

Here are some practical tips to reduce your exposures:

1. Check your local conditions. If AQI conditions are red (Unhealthy), purple (Very Unhealthy), or pants-on-fire maroon (Hazardous), you need to take action. If you are particularly susceptible to respiratory effects (asthma, cardiovascular disease, or as directed by your physician), be even more conservative and take action at orange.

2. Get inside. This is a mostly outdoor phenomenon. Inside doesn’t guarantee safer conditions, and not everyone can go inside (outdoor workers, the unhoused, etc), but usually indoor conditions will be somewhat better than outdoors. Close your windows and doors.

3. Turn on filtration if you have it. Your building HVAC system usually has a filter in it. Or maybe you have a portable room filter available? Or you’re an air pollution geek like me and you have a CR Box that you built? Time to turn those on. And operate them in the room you spend the most amount of time (your bedroom, your place of work)

4. Wear a mask. While most think of mask wearing as a Covid thing, they were first developed to reduce exposures to ambient particles. If you have to be outside, wear a high quality mask like a KN95, KF94, or N95 respirator. Your lungs will thank you.

5. Defer outdoor activities. You’ll [probably be just fine if you skip your daily run for a couple of days. Or maybe run on a treadmill in an air conditioned gym. Avoid outdoor exercise if possible because this increases your respiratory rate, which increases how much pollution you inhale. In general, the mornings are the worst for particulate matter, though check those conditions.

6. Check on others. Even though many people will be okay with breathing polluted air for a little while, not everyone is so lucky. If you have access to clean air in your home, find excuses invite others over. It’ll be fun.

Science worth reading

I’m often asked by students what kinds of science stories I spend time reading - not necessarily for my work and profession, but what science I’m just curious about. I’ll include a few topics that have caught my eye over the past few weeks. Find these interesting too? Maybe yes. Maybe no. Unfortunately, some are behind paywalls.

Mapping the world’s sea grass. Changing climate is forcing aquatic changes, too - sea grasses are really important for ecosystems, and really smart folks across Africa are racing to get them recorded.

Mr. Bean and his EV shenanigans. No idea Rowan Atkinson is weighing in on this topic, but I always find it fascinating when smart people write things that are not as smart as they could be (Atkinson has a degree in electrical engineering and a MS in control systems).

Volcanos erupting in Hawaii. Always amazing to see the power of the earth rear its head. The irony is not lost on me that this represents an air quality danger to the people around Kilauea.

Meow. Having lived in New York for a few years when I was younger, I would have been terrified to know there are this many feral cats roaming around. I like cats, but not this many.

Argentinian (or Spanish) invasion? This has nothing to do with science, but I’m a football fan (the one that almost all countries call football, but we Americans call soccer).

Other science stories that you find interesting? Post them here!