Beijing's AQI: How Bad Is It and What Can Be Done to Protect Your Home?

In the past six years that I have lived in Beijing, air quality has become an increasingly popular topic of discussion. The government can regulate it. They cannot regulate it. How bad is it? Can the kids go outside today? Where can I get replacement air filters cheap? Let’s post the AQI level on WeChat. The conversations can drag on and on. Everyone seems concerned about it, but I’ve met few people who can actually define it. So let’s start from the beginning – what is a safe level of particulate matter?

To find out, I did something dangerous and looked up the World Health Organization (WHO) Air Quality Guidelines (AQG), then I looked up particulates on Wikipedia, and then I curled up in the fetal position for a few hours and hid under the covers wearing a mask with the rooms air filters cranked on high.

As I am sure everyone will click the links and read the source material, I’ll be brief. The WHO AQG set the annual mean for PM2.5 of 10 μg/m3 (10 micrograms per cubic meter of air). That's Ten-Oh 10! That’s the high averaged out for the year. For a 24-hour mean, the limit for PM2.5 is 25 μg/m3. To reach a city average of 7 as it did one day earlier this month, it took winds gusting for 24 hours at 70-80km per hour. On another day, average PM2.5 was well over 200 μg/m3.

So what? The reason this matters is the well-documented health risks of any exposure. Essentially, the WHO said that there is no known safe level of exposure, but 10 μg/m and under was achievable and presented much lower relative health risks. What about an average of say 15 or 20 μg/m? Wikipedia broke it down like this: In 2013, a study involving 312,944 people in nine European countries revealed that there was no safe level of particulates and that for every increase of 10 μg/m3 in PM10, the lung cancer rate rose 22 percent. The smaller PM2.5 were particularly deadly, with a 36 percent increase in lung cancer per 10 μg/m3 as it can penetrate deeper into the lungs.[5]

So who wants to sign up for the long-term health study of exposure levels exceeding PM2.5 of more than 100μg/m3?  

Now that we have some terms defined, next time I’ll define what actions we can take, if any, to make our homes, children, and lives a bit safer with respect to Beijing’s overall poor air quality.

So, if below 10 is the goal, how do you reach that goal at home and how do you know you’ve reached it?

To find out, I invited Charlie Thomson of Environment Assured to come in and test our air quality. We run one IQ Air unit in the living room and three Blue Air units in the bedrooms, so I figured we were doing our part to make the home safe; after all, everyone agrees that you need to get air filters. Charlie laid out three important steps to make the home safe against particulate matter. 

Step 1 – Seal Leaks As Charlie went around our home measuring the particulate levels with our filters running normally, he also measured the levels leaking in from windows, fan vents, duct work, the vacuum, and drains (yes, your drains don’t just smell bad, they also send up PM2.5). It was clear from the readings on his equipment that we had brought the particulate levels down, however the leaks in the home were preventing us from staying below PM2.5 of 10 μg/m3 or even 25 in some areas. So we have some sealing work to do and a vacuum to replace (our 10 year old vacuum is spewing out PM2.5 over 100).

Step 2 – Proper Coverage  In our case, we probably need to add two more machines to ensure we have enough coverage to keep the home safe – an additional unit in the living room and one in the office. The discussion was never about brands but about the necessary number of Air Changes per Hour (ACH). The ideal coverage in a room is to have 5 ACH. This means the volume of air in the room runs through the filter 5 times in one hour. We are happy with the IQ Air and Blue Air units, but if we turn them on high, they both sound like, well, big noisy fans in the rooms. It’s fine to have a machine that can handle a large room, but if it is kept on a low setting, it defeats the purpose. Consequently, since we don’t usually go over setting 4 on the IQ Air, we need another unit in the living room to ensure the air is getting properly circulated.

Step 3 – Maintenance Having air filters is great, and changing the filters according to the manufacture’s specifications is important, but the machines also need to be kept clean. This means vacuuming lint traps and pre filters and even wiping down areas where fine dust can accumulate. Charlie recommended weekly maintenance for optimal performance. It is also a good idea to check seals around the home periodically. Window and door seals in Beijing typically break down after a couple of years and start to leak.

Once we have sealed things up and added two more filter units, Environment Assured will come back and retest to make sure we’ve reached our goal. Then I hope I can relax and breath a bit easier.

To learn more about Environment Assured and the company’s services you can email info@environment-assured.com or call 400 000 8320. If you wait for the options listed in Chinese to finish, someone who speaks English will answer the call.

This article originally appeared on beijingkids.

Photos: TheLugash (flickr) barbourians (flickr)