Every year, spring’s blossoms bring with them wave of pollen. For places like Beijing, it’s also the start of the ‘snowy season’, with the hundreds of willow trees producing their fluffy catkin friends and the sniffles that follow. But how can we avoid the uncomfortable coughing and sneezing? Which masks work best for protecting us from pollen? Can surgical masks, single-use face masks, respirators or even Pitta masks filter out pollen?
To answer which masks work best, let’s break this down into two parts:
1. How big are pollen particles?
Pollen particle sizes typically range from 10 microns up to 200 microns — about the width of a human hair. That makes them pretty ‘large’, as far as particles go. They’re bigger than most smog, PM2.5 and soot particles, but smaller in size than heavy dust and sand-like particles.
Looking at individual pollen types, they vary greatly in size. Most trees have pollen that are in the range of 50 – 200 microns. The smallest pollen known measures 9 microns, the pollen of mimosa pudica.
At four times bigger than PM2.5, pollen is much more likely to get stuck in our throat, nose and lungs, as opposed to being absorbed into our blood. That means keeping them out of our throat, nose and lungs, can help to reduce the impact they have on our bodies.
2. Can Masks Filter Pollen-Sized Particles?
Because pollen particles are fairly large, most masks will capture a high percentage of it. Data shows that even surgical masks can capture up to 80% of tiny PM2.5 particles. They even do a great job when wearing them. Since the size of pollen is bigger than PM2.5, surgical masks will do even better at capturing them.
Other masks, such as 3M respirators and masks focused at filtering out PM2.5 do an even better job of capturing particulates. The 3M masks tested by Smart Air were able to capture over 99% of particulates when being worn.
The Pitta Mask vs. Pollen
The Pitta mask is a popular mask in Asia, often worn by celebrities for its cool and stylish looks.
When we previously tested the Pitta mask, we found it scored poorly at capturing PM2.5 particles. It filtered just 64% of particles 2.5 microns in size – that’s even worse than surgical masks. For even smaller 0.3 micron particles, it was useless, capturing 0% of the particles.
However, the Pitta mask never claimed to be able to filter PM2.5 or other small particles. The Japanese Pitta mask brands itself as able to capture “99% of pollen”.
In our tests we only measured particles as large as 5 microns, because that was the limit of our testing machine. However, we can extrapolate the graph above up to 10 microns to work out how well the Pitta mask might capture PM10 particles. Doing so, we can see that the Pitta mask should be able to filter out over 99% of PM10 particles, including pollen.
What else can I do to protect myself from pollen?
1. Get an air purifier for indoor protection against pollen
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 them than PM2.5.
2. 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.
Bottom Line: How to Protect Yourself From Pollen and Hay Fever
Bottom line: Most masks–even surgical masks–filter out a high percentage of pollen particles. At home, air purifiers will reduce pollen particles in the air.
Paddy is the CEO of Smart Air, running operations from Beijing. He has a Masters in aeronautical engineering from Bristol University, UK having specialised in aerodynamics. An advocate for open data, free information and transparent business, he spends his spare time promoting honest business and social enterprise.