Category Archives: China public health

China public health

Here are all articles discussing public health in China: air pollution, food safety and many other health issues.

Leave a Reply

Rubber Ducky You’re The One — To Cause Diabetes and Cancer?

My boys are now both over two years old, but they still like the occasional chew on their toys, which are mostly made of plastic. Rubber duckies, Lego men, Brio trains — it’s still a ton of fun to put in their mouths if it makes mommy and daddy really mad. I choose my battles with them, but I try to stop them partly because I’m worried about the chemicals in the plastic. Surely, microscopic parts of that plastic must be getting into their systems? One set of bath toys was very typical, made in China but exported to America, from a company vowing they are “safe and dependable”, with standards that “meet and exceed” US laws. What exactly does that mean? What are these laws? Should I be worried? And just how well can I or any parent protect our children from all environmental harms?

When I think about our modern world’s reliance on chemicals and plastics, I’m reminded of what Donald Rumsfeld called the “known unknowns” – we know that we understand almost nothing about the safety of the 80,000 consumer chemicals created since World War II, because they’ve never been required to be tested on humans. As the WHO states in their 2012 report State of The Science of Endocrine Disrupting Chemicals, “the vast majority of chemicals in current commercial use have not been tested at all.


The chief concern is that some of these chemicals are endocrine disruptors, which are chemicals whose molecular structure is similar to our natural hormones. With this mimicry, they can bind to the same receptors that our natural hormones do, thus altering our normal endocrine activities which control  just about every aspect of our health. We are mostly worried about children because these endocrine disruptors could cause permanent damage during our most sensitive growth spurts: while still developing in the womb, and later during puberty. The most notorious example of an endocrine disruptor is diethylstilbestrol (DES), a synthetic estrogen which was given to many pregnant women in the decades after World War II as a treatment to prevent birth complications. But slowly it became clear that many newborn girls of these mothers were getting a rare vaginal cancer, and DES was banned and declared a carcinogenic — but even right now many of these same “DES daughters” are continuing to have reproductive health problems both for themselves as well as in their own children, which means some endocrine disruptors can permanently alter our DNA, affecting generations.

The US Endocrine Society published an even more damning document, their 2015 Scientific Statement on Endocrine-Disrupting Chemicals, which concludes that

…there is strong mechanistic, experimental, animal, and epidemiological evidence for endocrine disruption, namely: obesity and diabetes, female reproduction, male reproduction, hormone-sensitive cancers in females, prostate cancer, thyroid, and neurodevelopment and neuroendocrine systems.

The prestigious JAMA Pediatrics published their own review of endocrine disruptors in 2012, essentially agreeing with the WHO’s assessment that while hard data on humans isn’t very strong, there’s enough concerning data to conclude that “efforts to reduce EDC exposure as a precaution among pregnant women and children are warranted.” Chemicals such as BPA, PVC and phthalates are most often mentioned as causing harm in boys and girls, associated with infertility, obesity, cancers and neurodevelopmental problems such as behavioral issues and a lower IQ.

Plastic ID Codes and Properties. Source:
Plastic ID Codes and Properties. Click to enlarge. Source:

So what can we all do to protect ourselves? After all, everything we touch almost literally has plastic as part of it. I’ve found a few consumer groups and blogs that offer helpful advice for worried parents. My favorite is The Soft Landing blog, which has a very useful collection of safer product shopping guides. The Pediatric Environmental Health Specialty Unit also offers similar advice. Here’s a small summary of what most are advising:

  • Try to buy products (especially for babies) that are free of BPA, phthalates and PVC (The Soft Landing website has great blog lists).
  • Switch all your plastic food containers to glass.
  • With the Plastic Coding System, avoid numbers 3, 6 and 7 and try to use numbers 1,2,4 or 5.
  • Consider buying organic produce to reduce exposure to pesticides..
  • If you must use plastic cling wrap, only use PE wrap; minimize contact of cling wrap plastic with the food; and try not to microwave with the plastic on it. Especially don’t let the plastic sit on top of liquids, whether cold or hot.
  • Reduce indoor dust exposure by cleaning carpets and dusty surfaces regularly using a vacuum cleaner with a high-efficiency particulate air (HEPA) filter.
  • Always immediately transfer your restaurant leftovers into glass containers at home, and never reheat your leftovers or eat directly from takeaway plastic containers.

We’ve put most of these into practice in our home, so I feel a bit less stressed about this issue.  And the boys’ bath toys? While The Soft Landing blog reassuringly listed them on their list of safer bath toys, their own company rep emailed me to confirm they are “BPA-free, phthalate-free, and non-phthalate PVC”. So I am letting them munch away — for now. Choose your battles…


This post was originally published on my new blog at Please follow my new blog! (and my Facebook page

From Beijing to the Boonies: Moving Right Along

I am leaving Beijing.

After ten gloriously exhausting years in China, I, my wife and my two boys are saying goodbye to China — and hello again to the USA, for new adventures in a rural town in the Seattle area, surrounded by blueberry farms, pine forests, wrap-around water views, white-capped mountain ranges — and crystal clear skies, when it’s not raining.

There. I’ve finally announced it. What a relief. I’ve been staring at my blog’s word processor for weeks, trying to write an all-encompassing opus, an uber-elegy to my roller-coaster years here, trying to capture what it all has meant to me. But I threw away all of my early edits. Sometimes they were too preachy, too treacly, or worst of all: boring. So I decided to lower my ambitions here and just put out something — anything, really — mostly because my time here is quickly running out, and I wanted to give my Beijing patients a few weeks to say goodbye to me here in the clinic, as my last day is now less than a month away (the end of July).

Winslow harbor

So here’s my main point: I wanted to give thanks and express gratitude to all of my Beijing patients over the past ten years. If I don’t see you again this month, it’s been a true pleasure and an honor taking care of you and your families, hearing your stories and sharing my own. I hope I’ve made your lives here in China a bit more healthy and rewarding. And to the millions of readers of this blog and my other publications, I’ve been thrilled and deeply satisfied to share my advice with so many people, especially people across China with my Chinese translations and book.

I suppose I could, or should, go into details about why we’re leaving China after ten years. But in general, it’s a very personal decision we’ve made and we’re very happy about the change — but also appreciative of the many opportunities and benefits we’ve had here. Of course if I wanted, I could regurgitate a boilerplate expat-leaving-China catharsis, but I think that genre is a bit tiresome. And besides, I’ve made it very clear in my 600+ blog articles what I’ve struggled with here, and also how I’ve thrived despite the obvious handicaps of living in Beijing. The final tally, for me, is very much a net positive.

So as I wrap things up here, and clearly end this blog in its current form, I am filled with many emotions, most of them positive, which is where I prefer to stay. I’d like share a quote, from a speech I gave two years ago at the opening ceremony for the International School of Beijing’s pollution-free sports dome:

…On a final note, please don’t ever forget just how lucky you are, to be able to go to a school like ISB. What if you were born in China during the Cultural Revolution, with no schools anywhere for 10 years? Your career dreams never would have come true. Or what if you were born just across the street here in the village, and your public school still lets you play outside on bad pollution days?

All of us — adults and parents and students — every day should be thankful for our health, for our families, and that we have the chance to thrive and make our dreams come true.

I bid everyone farewell, finally ending with a few parting words of wisdom from those wise sages Kermit the Frog and Fozzie Bear:

Movin’ right along in search of good times and good news,
With good friends you can’t lose,
This could become a habit!
Opportunity knocks once let’s reach out and grab it (yeah!),
Together we’ll nab it,
We’ll hitchhike, bus or yellow cab it!

Buh-bye, Beijing…

Safe Salmon in China? Yes!


I love the unique taste of salmon, which is fortunate for me as it’s truly one of nature’s superfoods. Salmon is packed with heart-healthy omega-3 oils EPA and DHA, protein and vitamin D and also is low in dangerous metals such as mercury. I oftentell people to eat oily fish such as salmon at least once a week to dramatically decrease their risk for heart disease. A 2006 review study in JAMA  shows that a daily dose of only 250-500 mg of omega-3 fatty oils can lower your risk of sudden death from heart disease by 36%, and from all-cause mortality by 17%; more than 500 mg daily actually provides very little extra benefit. And as 100 grams (3 ounces) of farmed salmon has over 2 grams of omega-3 (more than wild salmon has), even one serving a week may be enough because the healthy oils can remain in our tissues forweeks. This is all great news, right? But when I tell my patients in Beijing this fantastic news, they usually reply the same way: “I’d love to eat more fish here, but I never know which store I can trust.”589px-Salmon_sashimi

When my wife and I first arrived in Beijing nine years ago, we first bought our fish and other meat from the large international supermarkets Carrefour and Walmart, mostly because we assumed (for better or worse) that these stores would have superior quality control and safety standards, especially with imported foods. And that worked well for many years, especially as these markets slowly started to sell more organic options. Later on, we discovered the German-run Metro 麦德龙 hypermarket, and we immediately switched almost all our meat and produce purchases there, due to their outstanding logistics and traceable food chain. In other words, we trust them, and trust is a really big deal here in China. Metro’s salmon is mostly from farmed ponds in Faroe Island, a very safe area in the north Atlantic which is antibiotic-free and also certified by the non-profit Aquaculture Stewardship Council (ASC). Ikea, just up the street from Metro, also has an impressive selection of imported frozen salmon from Scandinavian waters, again all certified by the ASC or MSC (Marine Stewardship Council), and at very reasonable prices. Both stores sell their salmon for ~60-70 RMB/500g. So for those of you who don’t trust your fish in Beijing: there’s my answer.

omega-3 Fatty Acid Fish Safety Doses
Comparison of omega-3 and mercury levels in various fish

We still love Metro and Ikea but our #1 choice now for salmon is the monthly group buy, called GroupBuyByBianca, organized by the staff formerly from the Chef Too restaurant. Once a month they’ll trek to Beijing’s wholesale fish market; choose farmed salmon from Norway, Canada, or Faroe Island; de-bone and vacuum pack and then deliver to your door in chilled containers. It’s a fantastic service, and we usually get half a salmon every couple of months which we store in our freezer. Bianca and the team also sell imported cod and other meats in season. To sign up and order, follow their WeChat ID “GroupBuyByBianca” or email [email protected]. The cost depends on market prices but recently is usually ~45RMB/500g plus 10% and a flat 65 RMB processing fee.

Our other newer options for buying fish and meat are again online. The first is the wonderful local organic farm TooToo, which I’ve mentioned before as a very trustworthy, internationally certified local organic farm with a terrific distribution chain, easy online payment, professional delivery service and unbeatable value of organic produce. It’s an awesome resource for Beijingers — plus their website at has English and Chinese! You can buy 200g bags of Norwegian salmon for 36-50 RMB each. Besides salmon, they now offer a large selection of meats from many different sources — check out their long list of imported fish here. We’ve had particular success with shellfish from Europe — mussels from Scotland and shrimp from Ecuador were delicious.


Where? Cost (RMB) per jin Notes
Ikea 69/500g ASC certified, Atlantic
Metro market 60-70/500g ASC (Faroe Island: Bakkafrost)
Carrefour market 128/500g Faroe Island
Jingkelong market 78/500g online store 90/500g (36 RMB/200g) Norway
Group Buy by Bianca ~70/500g (~95/kg+10% + 65RMB) Farmed: Faroe Island, Norway or USA
April Gourmet 123/500g (245/kg) Norway


Besides TooToo, there are now a bewildering number of players in China selling foods online via apps and websites, with ridiculous amounts of investments from all the big internet players and finance companies. One such store my wife uses often is called yiguo (易果) at We liked them initially for their imported fruits but they also have a decent selection of meat, including a special section for imported beef. Other large sites like yihaodianWomai and’s grocery store are notable because they both have their own supply chains and distribution centers, which in theory could provide consumers better quality and more traceable products (with quicker deliveries, I’ve noticed). Amazon China also has their own online grocery store. All of these e-markets carry a big selection of imported foods of all types, far more than you would ever see in any local market.

Many expats get their salmon and meat from the small international markets such as April Gourmet or Jenny Lou’s, and that’s fine of course, and it’s certainly convenient for many on the way home from work. I just think the prices can be a lot higher than other options (see the comparison chart below), and I also worry about low sales volumes in small markets in terms of food safety. Many people also buy salmon at local markets like the popular Sanyuanli market, but I personally feel they have extremely inadequate food safety there; most vendors’ meats sit in the open air at room temperature, uncovered, on wooden slabs, with flies buzzing around. Do I really need to break down how many violations of basic food safety I just mentioned in that one sentence? I wouldn’t recommend buying meat from any market anywhere in the world if it’s sitting at room temperature for more than two hours.

Notice the ASC certification label…

Besides making your own salmon, eating in restaurants is definitely the next best option. All you sushi lovers can easily get your weekly omega-3 fix with even a few slices of salmon. Beijing is blessed with plenty of excellent Japanese restaurants and salmon dishes. Our favorite sushi place is a small Japanese market called yuqing (鱼清) just next to Yotsuba along the Liangma canal waterfront across from the Four Seasons Hotel; you can choose your raw fish from their shelf and the chef will prepare it right there for you to eat in the store.

What about the big percentage of readers who take a daily supplement of fish oil, including myself? This indeed has been long recommended even by the American Heart Association, but unfortunately the most recent studies, much larger than earlier studies, disturbingly show very little benefit from the supplement. There must be something else besides omega-3 in the actual fish that provides the heart-healthy benefit. Anyway, when my supply runs out, I won’t be continuing that anymore.

So there you have it; I hope I’ve convinced some of you that healthy fish = healthy heart. And for Beijingers, it’s not nearly as hard as you may have thought to add safe salmon into your diet, even at a reasonable price. For those of you in China out of the tier one cities or not near a good market, now there are plenty of online options to get salmon delivered right to your door. If you’re really worried about trust, sustainable fishing, and seafood free of chemicals and antibiotics, just stick with vendors that have ASC, BAP or MSC certification stickers on the fish packaging — Ikea and Metro would be your safest bets.

In terms of general value, here’s a nice graph from the JAMA review showing relative money spent on different types of fish to get your daily 250 mg of omega-3:

Estimated Costs of Consuming the equivalent of 250 mg/d EPA + DHA From Fish


My Quest For The Ideal Air Purifier Is Over.

Update January 2016: My data below speaks for itself, but people should be aware of possible quality problems reported here.

I think I’m done testing air purifiers. Yes, I’ve said this before, and I admit I often enjoy crunching the numbers, but I think I mean it now. The only possible way I could be persuaded to test another model would be an amazing breakthrough in technology. But it would still have to be reasonably affordable, even under 1,000 RMB per machine. Crazy, no? Actually, it’s not, because I sold all my IQAirs and my Blueair and switched to six air purifiers which cost me a total of 5,200 RMB. That’s right; a total of 5,200 RMB, for six new machines. I hardly doubt I need to remind most of you that’s half the price of only one of the many popular machines on the market now. And as this article will show, I’ve proven that these new machines are keeping my family’s indoor PM2.5 under 10 ug/m3, which is the goal of the World Health Organization and thus should be everyone’s goal (read more about that here). So why would I even want to test anything else?

As to which machine, many readers probably already know my answer because I started to test them last year: the Xiaomi 小米空气净化器 at 899 RMB, covering 48 square meters (apparently there’s a newer, smaller model as well for only 699). I initially blogged about Xiaomi last year discussing my test results of indoor air purifiers under 1,000 RMB. After last year’s testing, I had replaced two imported models in bedrooms with the Xiaomi purifier, and my bedroom air has been just fine since the switch. Just a few weeks ago I made the really big leap, returning two large air purifiers in my front rooms with three Xiaomi purifiers (I needed one extra as the coverage was comparatively less). And for the record, I am getting no promotional money or free anything from Xiaomi.

In our nine years in China we’ve always used well known imported air purifiers to cover our front rooms, which are essentially one large open space covering 83 square meters. But the price gouging in China always galled me. So after last year’s testing of purifiers under 1,000 RMB, I was always thinking, why can’t I see if I can also replace these big machines in the front rooms with something of more value yet equally effective? The timing was perfect as we’ve had multiple December days way over 200, 300 — and the worst two days of pollution I’ve ever seen in Beijing in my nine years here, our 2015 Airpocalypse with readings over 600 and an eerily dark, yellow sky in the afternoon of December 1st.

Let’s jump right in to the only thing that matters: hard data. And maybe the most important test was Airpocalypse 2015. So here’s the bottom line: data from our Laser Egg PM2.5 monitor showed an outdoor average PM2.5 concentration of 465 ug/m3 over those couple days, and inside the front rooms only 25 ug/m3. That’s an astonishing 95% steady improvement over the worst pollution you’ll pretty much ever see here, and although it’s not at my ideal of 10 ug/m3, it’s still far below the 35 that most Chinese environmental teams shoot for anyway, and the 95% reduction is certainly way below the usually recommended 80% goal. And the machine’s weren’t even on the top, super-noisy speed but the middle speed, which is still fine for general conversation and TV watching. Here’s the graph from the Laser Egg app, with the red line showing outdoor PM2.5 and the blue line showing my living room PM2.5 (the left side axis is PM2.5 concentration in ug/m3 and the bottom axis is just the number of data entry points):

Red line: outdoor PM2.5 concentration (ug/m3). Blue line: indoor PM2.5 (Laser Egg PM2.5 monitor)
Red line: outdoor PM2.5 concentration, US Embassy (ug/m3). Blue line: indoor PM2.5 (Laser Egg PM2.5 monitor)

On more “normal” days the data was much closer to, and usually under, my aggressive goal of PM2.5 concentration under 10 ug/m3. Here’s the data from earlier November:

Red line: outdoor PM2.5 concentration, Beijing average (ug/m3). Blue line: indoor PM2.5 (Laser Egg PM2.5 monitor)

Even a quick glance at the graph above tells me everything I need to know: my living room air (the blue line) is generally exactly around 10, and always under 20 even as the outdoor air climbs up. And as Beijing’s annual average is 70-90 ug/m3, my three Xiaomi machines easily get me to my goal of 10 during those typical days — and at a nice auto setting with very comfortable sound level. For calculated averages over this week using the Excel spreadsheet data from the Laser Egg, my front room average was 6.1 ug/m3 when outdoor air was a relatively clean 61; 9.8 during heavier days averaging 136 outside; and a still respectful 14.4 when outdoor air tanked for a couple days at 220 (that’s an impressive 93% reduction).

You notice there are a few spikes on the blue line, but all of those are easily explainable as with any other air purifier I’ve had: either the windows were open while we were using our laundry dryer, or we were cooking, or the machines were accidentally off for a while and no one had noticed.

Here’s one more graph from my bedroom, again demonstrating even more clearly than last year’s test that a Xiaomi on quiet setting is perfectly effective, and easily just as effective as any machine I’ve ever tested, including all the far more expensive models. The calculated average PM2.5 concentration was 8.0 ug/m3, again nicely below my goal of 10. It was 8.6 ug/m3 when the outdoor air was a horrible 224 over two days; and 7.4 ug/m3 on two clearer days, when the outdoor air average was 69:

Bedroom data
Bedroom data, 4 nights (red line: outdoor PM2.5 concentration. Blue line: bedroom data)

So let me be perfectly blunt to those in China who say that an indoor PM2.5 of 10 ug/m3 is impossible and too expensive: I say that’s nonsense, especially now, certainly on the money side. A goal of 35 ug/m3 still gives everyone a 15% increased mortality risk, as the WHO specifically mentions in their Air Quality Guidelines. I do realize this is a sensitive concept for some readers, as many people have spent a lot of money on air purifiers, or even work for those companies. And it’s fair to point out that these Xiaomi replacement filters don’t last as long as others (three months, although they’re only 179 RMB), and their HEPA filter at 99.3% (rated H11) is not as efficient as most other higher-end machines’ filters, and maybe the machine’s solidity isn’t so great, and perhaps they may break down sooner than other machines. We simply don’t know yet, as these are new machines only a year on the market — which in itself should give people some pause. Also, the built-in sensor is quite inaccurate and pretty much useless to follow — but I’ve never found sensors ever reliable on any air purifier, and I always control all of them manually anyway (and none of the major brand machines ever had a sensor anyway). The sensor’s more concerning issue is that it thinks that a PM2.5 concentration of 75 ug/m3 and under is safe. That’s simply too high, and even the Chinese government rating of 35 would be more proper. I of course think 10 is best, but for a machine made in China I would think 35 is reasonable. So if people are using a Xiaomi and relying only on the sensor on auto speed, then indeed they still may be inhaling not great air. This again is why everyone, using any type of air purifier, should not be relying only on any machine’s auto setting ever (my personal opinion). You need to get a separate monitor and use that to test your air.) And yes, Xiaomi is mostly a cell phone company first.

But let’s be very clear here: I’ve mentioned many, many times that anyone living anywhere in polluted areas, whether China or India or Los Angeles, has an ultimate goal to get your indoor air pollution under the World Health Organization’s goal of PM2.5 under 10 ug/m3. The scientific data is very clear; any PM2.5 over 10 starts to have health effects. So people in polluted areas absolutely must have air purifiers indoors, where you spend 90% of your lives. At the very least, put one in your bedroom. And for heaven’s sake, make sure your children’s rooms are all protected.

So you’re more than welcome to get any air purifier machine you want, as long as you’re reaching your goal of PM2.5 under 10 ug/m3, and routinely monitoring your air afterwards (perhaps with the new Laser Egg, only 499 RMB) to make sure all is working fine. In terms of which air purifier is best, again I’ve mentioned often that all that anyone needs for indoor protection is a good filter attached to a good fan. I’ve tested many models over many years, in real world circumstances in my homes, and no particular model at any price point ever was so obviously better than the rest. This is why I am perfectly comfortable with my current setup.

And this is why I am done with testing. Probably…

Checking Your Indoor PM2.5, Cheaply, With The Laser Egg

UPDATE January 4, 2016: Here’s a great review article about PM2.5 monitors: click here; they praise the Laser Egg but also discuss its limitations.
laser-eggI’ve mentioned often that I feel it’s important for people who use air purifiers to make sure your investments are working well. For me, this means always keeping your indoor air PM2.5 concentration under 10 ug/m3 (read my explanation here). The only way to know this is to have a PM2.5 monitor to check your air. We can spend so much money on air purifier machines — but how are we sure they’re on the correct speeds, or in the best part of the room, or that the filters aren’t clogged and need to be replaced early? And how do you know if you need to increase their speed when the AQI is airpocalyptic?

You certainly can’t rely on the built-in PM2.5 sensors that many air purifiers have, as the vast majority I’ve seen are inaccurate and basically useless. No, the answer has always been simple — and complicated. You’ve always needed to buy a separate PM2.5 monitor, but the best ones are wildly expensive. For a few years I’ve been using a popular, more economical choice from America called Dylos, but their data was uncommonly difficult to download and convert to something we layman could understand.

Now, finally, we’re starting to see some reasonable options, and I’m thinking specifically of the new Laser Egg, an air quality monitor from Beijing-based environmental company Origins, set up by an expat couple. Many of you are already using this Laser Egg, which is available for a wonderfully reasonable price of 499 RMB. I’ve been testing a few of these Eggs for a few weeks, and I can finally say that consumers now have a real option for testing your air at home (or work, or schools, etc etc).

laser-egg-appI have some highlights about this Laser Egg:

  1. The Egg already has saved me tens of thousands of RMB in air purifier costs, as I’ve recently replaced my home’s air purifiers with a far more economical machine (the Xiaomi), and the Laser Egg data proves that these new machines are very effective. (I will blog about this soon).
  2. Their app (Breathing Space) is very useful, as you can sync all of your Eggs to your home wifi, and you can access their data anytime, anywhere in the world.
  3. The app also shows the local outdoor air, so you can immediately compare indoor versus outdoor air. Very useful.
  4. You can choose to monitor the AQI from China or from the USA, or even better, the raw concentration of ug/m3. I always use concentration because I can quickly glance and see if it’s under 10 or not. Plus it’s the most evidenced based, as 10 ug/m3 is the official recommendation by the World Health Organization, and then you don’t have to deal with the politics of AQIs, which are totally different in every country.
  5. You can also use the app to export the data to your email, and create snazzy Excel graphs like the one below. For example, the Egg’s weekly data spreadsheet has 5-minute interval data on PM2.5, PM10, humidity and temperature. Data geeks like myself will love it.
  6. Its battery charges by USB so you can unplug and stuff in your bag and walk around town with it, checking out your favorite stores and also the outdoor air anywhere.
  7. You can keep it on 24/7, in sleep mode, and always access the data via your app or the screen.
  8. The app also can send you instant messages warning you if your air is suddenly getting worse. For example, I was at work and got a cell phone pop-up warning that my front room air was worsening, which I confirmed on the app’s graphics. I called my wife at home and she realized that all our Xiaomi purifiers had been shut off after a power outage. I turned them all back on (using another app from my air purifier), and sitting in my office I watched the app to see my home’s PM2.5 improving minute by minute. How cool is that?
  9. You can also rig it to check pollution masks, sort of. See the video I made below, using the Laser Egg to test an incredible new pollution mask I’m helping to design, called Freeair. It’s a battery-powered outdoor pollution mask that delivers pure air via a tiny fan and an astonishing new filter, classified ULPA (Ultra-Low Particulate Air), far superior to N95, N99 or HEPA filters. It filters basically 100% of PM2.5 and also filters much smaller ultrafine particles by 99.99999%. As you see in the video, literally every molecule of pollution is filtered out. You’ll definitely be hearing more about Freeair soon.
  10. You can quickly check for leaks around doors and windows. You all have already sealed your windows and doors with the very inexpensive rubber strips, yes? If not, read this and then come back. Anyway, one horrible night with AQI over 400 I noticed from the Laser Egg app that my baby’s bedroom PM2.5 was strangely high. And sure enough, the rubber sealing was coming off a part of a window. I resealed it, and voila! Happy baby.
  11. The Laser Egg looks pretty cool, actually.

So how reliable is the Laser Egg, and is the price too good to be true? For accuracy, you can check out the company’s own comparison testing with the US Embassy’s monitor, but perhaps you’d rather see more independent tests such as this reviewer’s comparative testing with much more expensive sensors. It’s in Chinese but just from his photos you see they’re generally the same. I’ve discussed the Egg with some pollution experts in Beijing and they’re generally supportive but mention that humidity can mess with the numbers a bit, and also putting Eggs side to side will show slightly different numbers. But in general, on a consumer level, it certainly does what it says it does.

I personally think the Egg could be improved, but it’s accurate enough for me and very impressive for a first version. And right now I definitely have stopped using the Dylos and will only be using the Egg from now on. If you’re interested in the Egg, you can buy on their website here or also via their Wechat directly (ID: originstech). I’ve also seen it behind the cash registers at April Gourmet and Jenny Lou’s. Think Christmas stocking stuffer…