Tuesday, 3 January 2017

Air Quality Control

It is December here in China and we are nice and warm in our apartments, but there is a price to pay... It seems during the winter period that a lot of coal is burned to produce energy for our heating. This practice greatly reduces the quality of our air. The Air Quality Index (AQI) is reading 198 today indoors and people around me cough, yet only I am wearing a mask. Becoming a principal and being responsible for 200+ pairs of lungs has turned me into a bit of an AQI nut. The point of this blog post is to share my research over a one year period on air quality and to share the best methods I have found so far to keep our children safe.

AQI is a measure of pollutants in the air. Different countries have different levels at which they consider the air to be dangerous. In this blog post, I will be referring to the AQI in China but, more importantly, I hope to give you an understanding of particles 2.5 aerodynamic diameter per square meter. This term refers to tiny pieces of pollution per square meter in the air you breath. They are dangerous because they can enter the lungs and have been linked to numerous serious diseases mentioned here. Please see the table below for the amount of particle matter size 2.5 ug/m3 that is considered safe and dangerous in China. My advice to you however, is to learn to read the PM 2.5ug/m3 instead of the AQI and base your decisions on this. 
AQI China but note the left column (Source: Grandmaster Kevin via Wikipedia)

After explaining the problem, I would now like to share ways in which we can combat this problem and protect our children. I will start with the home as this is where our children spend most of their time, then move to the classroom, and finally to the entire campus. I will then discuss masks for when you are outdoors or in another polluted environment. One of the devices available now to monitor particles is the Lazer Egg. I find this device to be reliable and have tested it in various environments.
The Lazer Egg can be linked to the Air Matters app to monitor your home.
Here are the two key findings from my research:

1. Indoor air quality is only slightly lower than outdoor air quality on any given day.

2. Good indoor air quality can be maintained with a suitable air purifier and an understanding of the importance of to keeping doors and windows closed.
AQI inside my living room first thing in the morning without air purifiers running.

Our homes are usually one floor apartments. This area can be easily controlled. The key is to have an air purifier running in every room where you want to maintain the air quality. The room should be sealed as much as possible. That means doors and windows need to be closed. You do not need to worry about stagnant air in the apartment. I say this because, as soon as you turn the air purifiers off, the air quality decreases quickly, meaning outside air is coming in constantly. This would not be the case in a properly sealed environment, but I have only seen one of these thus far in my time in China. I discuss this environment below in the campus section.

AQI 220 in bedroom with purifier off.
I have tested a number of air purifiers and recommend the Xiaomi Mi Air Purifier 2. The basic model for 699 RMB works very well for a normal sized room. I have compared this to a Philips air purifier that costs 4500 RMB and the results are every bit as good. It can be controlled from your phone and estimates the air quality. It is not entirely accurate, however, but gives you a good idea. For a double room, a dining and TV room together for example, two purifiers would be required. They should be running 24 hours a day and, most importantly, be in the bedroom where our children sleep for up to ten hours.

AQI down to 17 after 20 mins (Room 12m2)

I have also learned that there are other toxins in the air besides the PM 2.5. A great way to combat these is by having plenty of green leafy plants throughout your home. They purify other toxins out of the air. 


The home is easy to manage, but the classroom is more difficult for a number of reasons. 1. It is usually a bigger room. 2. There are more sets of lungs to care for. 3. Most students and teachers have not been educated on how to control this environment. For a large classroom, a more powerful air purifier is required such as the Honeywell air purifier below. Otherwise at least two of the smaller purifiers are necessary. Again, however, I repeat, if the teacher and students leave the door open to the hallway or open windows, the air quality drops dramatically, very quickly. If the teacher and students diligently keep the door and windows closed and the air purifier on high, the air quality can be kept at a healthy level throughout the day. This particular part of the research was carried out on the highest pollution day of the year so the Honeywell was really put to the test. The classroom was also very large, 80m2. On a day when the AQI is at about 200 the Honeywell will get the classroom down to 40 or lower. They are excellent machines but very expensive. The school in question has rented them from Honeywell. They come to maintain the filters.

The Lazer Egg AQI maxes out at 500, this is another reason to read the PM2.5(ug/m3)
Inside AQI on the worst day of the year so far.
80m2 classroom after Honeywell running for 30 minutes
PM2.5(ug/m3) and AQI after Honeywell running for over an hour

Without quality construction, it is impossible to keep the public areas of a school campus safe (halls, cafeteria etc.). Properly sealed doors and windows are a must, as is a ventilation system that pushes bad air out and pushes good air in. If you are in a workplace without this kind of construction and technology, then just work on keeping your classrooms and offices safe. This can be done by following the instructions above, but requires a lot of reminding (doors closed, purifiers on). There is a school in Beijing that has invested heavily in air quality. It is called The Western Academy of Beijing. Information about their air quality system may be found here. It pressurises the entire building by blowing clean filtered air through large cylindrical sacks throughout the halls. The windows and doors are sealed to high standards and, when a door is opened to enter the building, the pressurised clean air shoots out, preventing the bad air from coming in. They are vigilant about keeping doors closed.

Clean air is pumped into the campus (windows completely sealed)

The inside of the building is pressurised with clean air
Lazer Egg inside the primary school campus at WAB
A dome filled with purified air for children to play inside.

When you have to go out in polluted air, the only way to protect yourself and your family is by purchasing quality masks. Remember that, in a taxi, on a bus, or in any regular building the air quality is as bad inside as it is outside, so keep your mask on if you want to keep the 2.5s out of your lungs! There are lots of masks coming out now that have good filtration of the 2.5 particles, but I have learned that the seal around the face is the key component. 3M masks are the standard in China for adults. They advertise keeping 90-99% of the PM 2.5 out depending on the model. The model that advertises keeping out 99% of the 2.5 is the one you should purchase, but I have not been able to find it yet and have settled for the 3M9001V. 

The other fabric masks such as Cambridge or Vogmask masks have good filtration but a terrible seal. For this reason, I recommend the 3M brand above, for adults. If you have facial hair or do not diligently ensure you form a good seal, you might as well put on one of those medical masks which are completely useless. Follow the directions carefully on the 3M box on how to create and test a good seal. This is very important, especially how to mould the nose band properly. 3M do not manufacture masks for children so for my girls I purchase the Cambridge or Vogmasks as they have child sizes, but the seal is terrible so I do not know if they are effective at all.

I wish I had known all of this information 2 1/2 years ago when I first came to China, but, as always, I am still learning. I hope it is useful for you in keeping your family and students safe.

References & Thanks

Thanks to: Grandmaster Kevin, Kirsten Lalor, Dr. Landon Darelik, David Brooker, The Principal's Training Center Network & The Western Academy of Beijing.

Further reading: http://www.myhealthbeijing.com/