You were probably advised when you were very young to not eat the yellow snow. What about yellow sand? It’s that season again in Japan, and we are again being blessed with the wonderful dirty, gritty sand from our neighbors here in Japan, coating everything in a nice uneven blanket of yellow that seems to get into everything.

And if you live in Japan, you might have also heard of the evil curse of PM2.5 that newspapers and electronics stores love to throw around as a buzzword. This mysterious cloud of gunk likes to come and go as well these days. Although I wasn’t able to pull up some numbers, it seems to be getting worse and worse each year.

Yellow sand and PM2.5 come to Japan by way of wind currents that shift around during the Spring season. March is especially worse for this. During almost the entire month, you can find yellow sand on your bikes and cars. Regular washing doesn’t seem to help that much as well because it just comes back the next day. So, what gives with this yellow stuff? And this mysterious PM2.5 cloud? And is there anyway to combat it?

Asian Dust or as it is called by the Japanese Meteorological Agency, Aeolian Dust, comes to Japan from the Gobi desert in China. It so happens that the Gobi desert is a good 2000km or more away from Japan, which means that this sand somehow manages to get sucked up into the upper atmosphere and then dumped thousands of kilometers away in Japan.

And usually it it is fairly light. You can hardly see it on most days. But, I have seen it come down like rain. So thick, it is like a yellow smog. On those days, you need to stay inside or wear a good mask. Otherwise your throat will be coated with it and you’ll be coughing it up for a week. I know from personal experience when I got caught outside and I had to ride my bike through it for about a kilometer and a half. Big mistake.

I’ve heard from one of my students that is an entomologist (bug scientist) that even small insects get sucked up this way as well and reek havoc on crops in Japan. And the mixture can also include pollution as well as fungi and viruses that somehow amazingly survive the journey. It’s a nasty mess.

The problem has apparently been around for thousands of years. But it has recently been getting worse due to increased desertification in China providing more sand to kick up. And, of course more pollution.

But there is also another little treat that greets us here in March and in other seasons like last fall, and that’s PM2.5. It stands for particulate matter, specifically pieces that are smaller than 2.5 micrometers, which roughly 1/100th the width of a human hair.

Particulate matter of this size are usually made up of toxic organic compounds and heavy metals. Although this may sound like a typical weekend for you, it can have some rather nasty side effects that you might want to look out for.

Normally your respiratory system does a decent job of keeping gunk out of your body. You’ve got nose hairs and mucus and all sorts of tools to trap crap from flowing down into your lungs. However, PM2.5 is too small and manages to bypass all that and get absorbed into your body.

Short term effects include things like aggravated asthma and respiratory problems to even premature death if you have heart problems. Long term effects, of course, cause things like chronic respiratory problems and heart disease.

You can begin to see why a few people are freaking out about it a little. And since the media and electronics stores have been hyping it up, it is something that has been on everyone’s minds of late.

First of all, it’s important to know when a giant cloud of nastiness will be invading your neighborhood. Luckily, the Internet has a few handy tools to help you with that. Surviving in Japan has a great post going over the main websites where you can check latest air quality in your area.

The one thing I would add to that site is a handy little iPhone app that I picked up that has been really valuable if all you need is a quick check. Be sure to set your region in the settings. The app itself might be a little hard at first to get around in if you are not that good at Japanese. The keywords are 汚染 (Osen, pollution) and 黄砂 (kousa, yellow sand).

I’ve found this app to be fairly accurate. It was able to warn me about the big cloud that hit Osaka about a month ago. The color coding is a little weird. Blue is the lowest level, then green, then orange, then red? (not sure, it hasn’t been that bad yet)

On bad days, you have the option of dawning a mask for your morning commute to work or just staying inside. If you wear a regular mask, the kind you can pick up for about ¥100 for 40, you can reduce intake of particles by about half at least according to this site. Using heavier-duty 3M masks cut it way down, but will cost you around ¥100 each.

Air purifiers and air-purifying air conditioners are a real hot item now in Japan. We are guilty of buying into the trend. Mostly because every brochure we see of said devices has a young mother and child playing near the devices, implying that you should buy them to protect your family.

And yeah, I’m a sucker for that. We had to get new air conditioners for our house and I ended up upgrading to the Sharp Plasma cluster-enhanced ones, so that I can be ‘rest assured’ my family won’t be attacked by deadly PM2.5 while they sleep. And now I’m broke, but I feel slightly assured I guess.

So, you might be thinking that’s all good, but what a more permanent solution? How about a future without nastiness in the skies.

Well, as with a lot of issues in Asia, there is a lot non-communication going on about it. The problem obviously needs to be solved in China, but there are a lot of issues with that. First, their economy is tooling down the road of modernization at 1000mph and changing the engine on that is going to prove difficult. Second, it is a really expensive, in terms of money and time, problem to fix.

It’s not like China is going to slough off the problem for much longer. They can’t. If you think the air quality is bad in Japan, it’s a lot worse in China. And people dying of lung cancer is not good for any economy. So my guess is they will at least make some attempts to mitigate the effects.

In 2007, South Korea sent China some trees, but they unfortunately used them to line highways instead blocking the sand. In 2009, South Korea spent 50 million won ($42,000) to plant some 72,000 trees in China, which seems like a small price to pay to attempt to fix things.

Of course, Japan has spent significantly more in foreign aid for China to help prevent pollution, but it is a huge problem that needs a concerted effort. My hope is that relations normalize a bit and everyone can stop disagreeing over some inhabitable rocks, so bigger issues like gunk in the air can be discussed and focused on, but that’s just a little dream I have.

Are you a sucker for air purifiers? Would you or do you wear mask to work? Let me know in the comments below.