Sunday, November 25, 2018

Air Quality and Pollution in Hong Kong - My Research Process

The weather is getting cooler in Hong Kong, and "winter" is approaching.  I use that term very loosely because it would be rare for the weather to fall below 40 degrees Fahrenheit here (dropping below 50 degrees Fahrenheit is already newsworthy), and only on the very coldest of days.  However, the cooler weather does signify a change in the air quality here. 

In the past, Michael and I have been, admittedly, pretty cavalier about this.  I knew the air quality was bad and I occasionally checked the AQI (Air Quality Index) but not very religiously.  I purchased a Sharp air filter quite a few years ago, barely changed the HEPA filter, and ran it when I knew the pollution was at its worst.  For nearly three years, we lived in a tiny walk-up apartment without a front door (seriously, just a metal gate) which meant that we essentially had a front row seat to all of the gas exhaust and fumes that were churned out of the taxis and scooters that zipped by our front door morning, afternoon and night.  I got not one but two eye infections.

It has been better since we have moved to our current place, but we have also become a lot more attentive to these issues now that we have Lola.  This week, I decided that it was finally time to do something about it.  So many children in Hong Kong have the "Hong Kong cough" due to irritants in the air.  I started out by canvassing friends and reading articles about what exactly we're trying to "fix" when it comes to filtering our air.  With the caveat that this is all from a layperson's perspective, I still hope it's somewhat helpful (to those who are in a similar predicament) or at least interesting (to those lucky ducks who live in say, Montana, or Auckland).

I knew enough to know that I needed to buy an air filter to help me "purify" the air in our apartment (in my mind I pictured a Brita pitcher but for gaseous elements), but not much more than that.

What I've learned is that PM2.5 is the evil thing that we are most worried about when measuring the quality of air - and then also TVOCs when measuring the quality of indoor air.  PM2.5 refers to those fine particles that are less than 2.5 micrometers in diameter, and are so small as to be invisible to the naked eye, but cause reduced visibility and for the appearance of the air or the to appear "hazy".  They pose the greatest risk to our health and well-being.  TVOCs refer to total volatile organic compounds, and essentially refer to the kind of very bad, no good substances that may cause, or are highly correlative to, damage to our organs and central nervous health system.

Hong Kong (and actually, lots and lots of countries and cities around the world) has a bunch of highly technical, huge PM2.5 particle machines installed throughout the territory, easily accessible to the public via their website (and a handy dandy app) called HK AQHI, which you can use to see just how bad the air quality is in your current area.  The problem, though, is that a lot of places (for example, the entire south side of Hong Kong) do not have any PM2.5 machines.  In addition, if you are really serious about monitoring your air quality, one of these machines does not help you with your individual environment.  What I failed to realize before embarking on this learning/shopping journey is that indoor air can be even more toxic than outdoor air.  Sure, you're worried about pollutants and smoke and dirt and dust, but all of that gets trapped inside your apartment or house, coupled with all of the stale air... not ideal either.

What to do?  Enter the air quality monitor.  These allow you to test the air in your very vicinity - in the rooms you are actually residing in - so that you can determine when to turn on your air filter, when to close your doors, and when it's okay to shut the air filters off and throw the doors open to enjoy the day.  If you're living in very dire conditions then this can probably be done on a visual or sensory assessment, but otherwise it can be hard to tell based on visual cues.

There are very many air quality monitors, which either reside in the air filter that you buy, or which can be standalone.  This monitor will tell you how bad (high) the PM2.5 number is.  From what I've been reading, ideally we should be striving to reach a PM2.5 of 10 ug/m3 or less.  I know plenty of people who do not have a standalone air quality monitor, and plenty of people who rely on the one built into their air filter.  But based on consumer feedback (comparing readings from both) I feel pretty confident that the monitors built into the filters do not achieve the level of accuracy that I want.

Now onto the actual purchasing decisions, because, once you know that there is bad air around you that is potentially very hazardous to your health, the next question is, how do you fix it?

After reading quite a lot of blog posts and articles on this subject, I finally decided, based on many friends' recommendations, to give the newest generation of Xiaomi air purifiers a go.  These blog posts (here and here) did a lot to persuade me.  While the Xiaomi isn't perfect, I was ultimately sold given the footprint, its innovative cylindrical design, the large fan, and the affordable filters.  Everyone tells me it is very quiet and there is even a night/sleeping mode.  It comes with wifi connectivity to link to our phones, but I will not be using it as I don't trust the Xiaomi monitor

I decided to try the Laser Egg 2+ for my particle counter.  It got some bad reviews on the connectivity for the phone app, but I decided to give this one a try because it looked to have the most user-friendly interface, was portable, and was the most reasonably priced (the others I kept hearing about were the Dylos and the Node).  These reviews from g trusted (here, here and here) helped, along with other articles, to sway me.  I also liked that Laser Egg allows you to set the AQI to that of a different country.  For example, if you set it to the US AQI instead of China's AQI, you will suddenly discover that a lot of what was "acceptable" air quality suddenly becomes "unacceptable."   This is not the blatant deceit that you may think at first - developing or industry-heavy countries are genuinely permitted to have more lax AQI indices.

If I really feel like nerding it up, I might carry my Laser Egg around with me to see how the air quality compares at different spots in my daily life.  It could be a very interesting and enlightening experiment.  Yes, this is what it has come to...

So far, I have only had the Xiaomi air purifier for two days and I am still waiting for my Laser Egg.  Once I get the whole kit and caboodle set up, it will be good to check how effective this all is.  Finally, I still need to tape up the "leaks" around our balcony doors as I think that also plays a huge part in how effective the air filter can be.

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