Spring is in full bloom, and that means “April Snow” is at its peak.
But what exactly is this white fluff in the air?
The white fluff in the air is a combination of pollen and catkin. Most people know what pollen is – a fine powdery substance of microscopic grains discharged from flowers. The catkins that blanket Beijing, on the other hand, are petal-less flowers that capture or release pollen.
The smallest pollen particles are 5 to 10 microns. Large pollen particles are as big as 160 microns — about twice as big as a grain of sand. Because these particles are big, most of them will get stuck in our throat, nose and lungs, rather than being absorbed into our bloodstream, which smaller PM2.5 particles can do.
In that case, how does pollen affect us?
PM10 particles like pollen can get stuck in our nose, throat, and lungs, causing irritation and inflammation. This leads to respiratory and cardiovascular problems which could cause higher mortality rates.
It gets even worse for people with allergies or ‘hay fever,’ because these people get a second attack. Their body’s immune system overreacts to these particles, triggering cold-like symptoms and even asthma.
Just how many people are affected?
It is estimated that a whopping 40% of the population worldwide has some degree of allergic rhinitis. In general, .
How can we protect ourselves from pollen?
There are a few simple measures we can take to prevent allergic rhinitis:
1. Wear a mask for outdoor protection
Because pollen particles are fairly large, most masks will capture a high percentage of pollen particles (as long as they fit your face well). Our tests show that these common masks do really well at capturing tiny particles (0.3 and 2.5 microns in size) and therefore. Even tests of surgical masks found that they captured close to 100% of particles above 2.5 microns.
The Pitta mask is one popular pollen-specific mask from Japan which is popular in China right now. Our tests found it did well at capturing larger pollen particles. But it did shockingly badly at capturing PM2.5.
If you live in a place with both pollen and PM2.5 pollution, like China, 3M N95 masks are a proven and inexpensive means of protection.
2. Get an air purifier for indoor protection
Plenty of research data shows that any air purifier with a HEPA filter will capture pollen.
HEPA filters can capture virtually 100% of particles over 2.5 microns. Since pollen particles are all larger than 5 microns, it makes sense that air purifiers can do an even better job of capturing pollen than PM2.5.
Make Your Own Low-Cost Pollen Destroyer
Big air purifier companies charge outrageous prices for air purifiers, like this popular IQ Air that costs over US$2,000 in China.
Smart Air is a certified B Corp that is working to spread the simple science behind air purifiers and lower the cost of clean air. Make your own DIY purifier or check out our quiet, empirically backed, no-nonsense purifiers.
Kang Wei is a chemical engineer from the National University of Singapore. He’s currently working on R&D and engineering at Smart Air.