Beijing Air Quality is Officially Beyond “Crazy Bad” — why and what can you do?

BJ PM2.5 air pollution index is beyond "crazy bad"

Screenshot of BJ Air Quality (LongCat Android app) shows that PM2.5 pollution level is 24 times higher than the US EPA healthy level (35 micrograms/m3)

Beijing’s in the international press again and unfortunately, it’s for the color of the sky again.  A year after the US Consulate caught the world media’s eye for labeling air quality reporting results as “Crazy Bad,” this week has had levels of pollution that have made “Crazy Bad” look downright tame.  The New York  Times article has been burning up the airwaves.  We’ve been getting a lot of questions and understandable concern, so I thought I’d put some facts out to share.

If you haven’t been reading the news, reading the US Consulate’s air reporting site, or checking your iphone apps, a quick glance to the skies shows that something is not right. We’ve been shrouded in a gray haze that has far exceeded even the air quality index (normally maxes out at 500, but topped out at 755 two days ago).  By comparison, the air quality index in New York City, using the same standard, was 19 at 6 a.m. on Saturday.)

So what’s the deal?
* For the past week, levels of particulate matter (called PM2.5 or airborne particles measuring 2.5 microns in size or smaller, about 1/30th the width of a human hair) has been hovering between “Very Unhealthy” and “Hazardous”, which are levels 5 and 6 on the Air Now system (which the US Consulate uses). 1 is best, 6 is worst. The levels reached this week are the highest that have ever been measured since the AirNow system began reporting 2 years ago.

Why is this happening?
* Experts don’t agree on any single cause. I had a discussion tonight with a friend who heads up the school of public health at Fudan and is possibly the best known PM expert in China and even he can’t put his finger on a single factor. Most likely, it’s a combination of a few things.
* Farmers burn their crops in the fall, so air quality is usually a problem around this season.  However, I haven’t seen any burning recently around here.
* As temps fall, people increase use of heaters, raising electricity needs, requiring more energy production, which is predominantly coal-driven. Coal = major particulate pollution source. Factories also are a major contributor to this industrial pollution.
* Mother nature. Thermal inversion, windless days, and other meteorological effects combine to create conditions for smog to hold in place rather than blow away. This is the most reasonable cause since cars didn’t suddenly increase and factories didn’t spring up overnight. Quite simply, the weather isn’t getting rid of the crap that is always getting produced.

What does this mean?
* There is a very real, and immediate health effect on almost everyone. In the Great London Smog of 1952, it’s estimated that over only 5 days, 12,000 people died and 100,000 fell ill due to the heavy particulates.
* Most common effects: difficulty breathing, harshness in throat when swallowing, elevated blood pressure, increased chances of asthma attacks, headaches (I get these first)

What can you do?
* Stay inside as much as you can as long as levels are high (ie. in the unhealthy range (>150 micrograms/m3) or limit outdoor exposure to things that don’t increase breathing rate. (Feel free to share any of these links to your school administrator if they don’t have a bad air policy)
* If you need to go out, wear a N95-rated mask, which filters out 95% of all particulates down to 0.3 microns in size. This doesn’t mean the cotton masks that ayis and workmen wear or surgical masks. This is the white mask made by 3M. Contact me if you need some. The World Health Store also carries the Respro type, which is a less disposable type.
* Monitor the air quality outside, which varies by day and time. The US consulate is good for hourly readings and can be found here: . Plenty of free iPhone and Android applications also can be found if you search “China air quality”
* Close your windows. Normally, I encourage ventilating 2-3x per day to rid all the CO2 and chemical buildup, but as long as levels are high, minimize this. In the office place, you may have to be proactive. Culturally, Chinese staff like to keep windows open because of a greater concern about chemicals instead of particulate pollution, which is invisible and has no smell.
* Turn on your filters. On high. See next section.
* Vacuum frequently with a HEPA-filter equipped vacuum and wet wiping or mopping. This will capture and remove settled particulates, which will increase during this time. Vacuuming with a bad vacuum will just suck it in and then spray it out the back, so bad.

So, do filters really work?
* Yes. Just as much of medical science is learned during battle, so do environmental consultants learn the most when air is really bad. Earlier, I measured the PM2.5 level on my terrace with a laser particle counter at 250 ug/m3. (the Consulate was reporting 248). Indoors, where I hadn’t ventilated overnight, the level was 180.
* After I opened the windows, the levels increased to 220. I then turned on my air filter and logged readings every two minutes.
* After 20 minutes, level was 80
* After 40 minutes (total), level was 28
* After 60 minutes (total), level was 17.
* For reference, the Chinese national draft standards for PM2.5 is <75ug/m3 and the US EPA is <35ug/m3.
* So, in one hour, the filter reduced levels from 220 to 17.
* Note: filters do need to be changed. I measured the PM levels at the air vent of the air filter in this test unit and it was about 3ug/m3. Downstairs, the exact same filter, but with a filter that was a month overdue for changing (for shame, I know) read 22 ug/m3. (second note: I have changed that filter)
* The takeaway is that any HEPA-equipped filter is better than none. They really do work, some are quieter, some look better, some use less electricity, some are built to last, but anything that is real HEPA-equipped will help you.

Hope this has helped some — if you want to understand what the Embassy reported numbers mean and how micrograms/m3 differs from AQI, I wrote a blog article about it awhile ago that explains here.   We also work with Alen Air, Blueair, and IQ Air, and can recommend the right types of filters for different situations and budgets.  Since we have the numbers and see these at work on a daily basis, we know how to best use them to keep the PM down.  Drop us a line because folks, if you’ve been looking for a time to finally get a filter, it’s about that time.

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Beijing Air Quality is Officially Beyond “Crazy Bad” — why and what can you do?

  1. Michael says:

    thanx for this very nice article. Do you have any recommendation to measure the air quality?
    Based on your article, I’ve checked laser particle counters and they seem to cost 2,000 USD. Is there a cheaper alternative? Or may be is there a way to rent a particle counter for one day, to do some testing?


    • Louie Cheng says:

      Hi Michael, air quality has a lot of different pollutants. Indoors, the most important measures that we typically use as an indoor air quality testing company are: PM2.5, total volatile organic compounds (TVOC), formaldehyde, benzene, carbon monoxide, radon, and relative humidity. Of these, in China, only carbon monoxide and relative humidity can be tested accurately and reliably with self-test kits or instruments costing less than about US$200.

      Water is better in terms of being able to get good results with home testing kits, but air is not. Check out an earlier blog post about self-test formaldehyde kits available on Taobao.

      We don’t rent instruments without our techs to go along with them — our laser particle counter, for instance, costs US$7000, so we’re a little protective! But we do “rent out” a technician with the knowledge and capability to test all of these for a half day or you can just consider a testing which starts at 2500rmb with full reporting and interpretation of the results.

  2. Marcus Solberg says:


    Where can I buy 3M masks and filters here in Beijing? I don’t really want to buy from Taobao, since I suspect there are many fake ones.

    I would also like to get a sports mask, with filters, for running outside or on the treadmill at the gym (since the air is probably not much better in the gym than outside).

    Also, I’m wondering if having a lot of plants (like big stuff with lots of green) does anything for the air quality?

    Thanks for an interesting article!

    Oh, and one more thing: My vacuum cleaner has a “micro filter” but it’s not hepa. Should I get a new vacuum cleaner or is micro filter good enough?

    Thanks again!


    • Louie Cheng says:

      Hi Marcus,

      Yes, I’ve seen more than a few fake Taobao masks. If they feel like reinforced paper, chances are they are not the real thing. Also if they are too cheap to be believed (<10rmb). The real item feels a bit like double-thich cotton, but tightly woven. Or, if you're near the Hujialou subway stop on East Third Ring Rd, drop by our office for a free testing (we'll check your mask).

      We just restocked a supply of 3M N95 masks in two different styles. The base version is durable, tried and true and runs 30rmb each or 200rmb for 10. The version with a one-way valve that reduces fogging and eases breathing is 40rmb (or 300 for 10)

      World Health Store (WHS) stocks the Respro masks that some people prefer for exercising. I believe they run for about 250rmb.

      Green plants are useful for reducing CO2 and increasing oxygen in limited amounts, but are ineffective for PM reduction.

      Not sure about the "micro" filter on your vacuum. HEPA usually has filter output of <20 ug/m3. Conventional usually around >60ug/m3. Industrial vacs often test at >120ug/m3. For more info read our past blog post here: The HEPA vacuum cleaner — an unsung weapon against air pollution

      Thanks for reading,


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