{"id":50744,"date":"2016-07-01T17:25:39","date_gmt":"2016-07-01T09:25:39","guid":{"rendered":"https:\/\/www.chengduliving.com\/?p=50744"},"modified":"2016-07-01T17:32:30","modified_gmt":"2016-07-01T09:32:30","slug":"pollution-questions-answered","status":"publish","type":"post","link":"https:\/\/www.chengduliving.com\/pollution-questions-answered\/","title":{"rendered":"Chengdu’s Air Pollution: Questions Answered by Local Specialists"},"content":{"rendered":"
Chris: The three cities listed here all have very unique characteristics, but we will try and provide a simple answer. London, as most may have guessed, is not even close to any large Chinese city in terms of PM2.5 yearly averages. London\u2019s yearly average levels, according to research done by King\u2019s College, are around 15 \u00b5\/m3 (15 micrograms per cubic meter). The next best in the group, in a very distant second place, would be Chengdu, coming in 4x worse at around 80 \u00b5\/m3. Beijing would bring up the rear with an average of around 100 \u00b5\/m3. The numbers vary depending on where you test in the city and during which timeframe, but this should help to illustrate the point.<\/p>\n
<\/p>\n
One thing the yearly averages don\u2019t tell you is how the pollution is spread out between good days and bad days. Chengdu is very consistent in its poor air quality. Most days in Chengdu are just not good, having a medium level of pollution, which would be considered unhealthy but not at hazardous levels. Very rarely will Chengdu have great days though, where PM2.5 levels are within WHO or EPA standards. The good news for Chengdu is that it does not have many hazardous days and the majority of these are concentrated in the winter months. Beijing is quite different in that it is anything but consistent. There will be days where levels are below what would be seen in any major western city. Two days later, however, it might feel like being stuck in an elevator full of people smoking.<\/p>\n
Chris: The first step would be to learn a little bit about pollution patterns in the city. To put it simply, the air is always bad by international standards and tends to be the worst in winter and best in the summer.<\/p>\n
The next step would be to evaluate where you will be spending the majority of your time. One of the most common questions we are asked is which mask we would recommend for outdoors? This is a good question and one that should be asked. However, a better question should be \u201cwhat should I be doing the other 23 hours a day that I am not spending outdoors?\u201d This question should then further be broken down into what should be done at home, which is an environment entirely in your control, and what should be done at the office\/school\/factory where I spend my days, an environment that can also be controlled to an extent.<\/p>\n
At home you should be keeping windows closed almost all the time. Very rarely are levels outside low enough that opening windows is safe. Nonetheless homes need to be ventilated regularly to help avoid stuffy indoor environments and indoor pollutant build-ups (chemicals such as formaldehyde from furnishings etc) as well as to encourage air circulation which can help reduce mold growth (a largely unrecognized issue in China). Your home should also be cleaned regularly with either a HEPA vacuum or a wet mop so that PM2.5 particles can be physically removed, not just sprayed around the room if you were to use a regular vacuum. The PM2.5 particles will inevitably make their way inside through the opening of the front door, leakage in the building and also being brought in on your clothes and shoes.<\/p>\n
The most important item that every home should have will be an air filter. We could write a whole separate article on how to choose a suitable model, but suffice it to say that it needs to deliver enough filtered air for the space (see the Cubic Meters an Hour CMH that is listed for the model and the CADR rating). Ideally, you would have filters in every room or, if not possible, have a filter running in the room you are in and then moved into the bedroom before bed. Last point on this is to run your filters on high when first turned on for at least an hour and, ideally, keep them on a medium speed afterwards.<\/p>\n
<\/p>\n
Controlling the environment at work will be a bit more of a challenge but, seeing as you will most likely be there 8-10 hours a day, is a necessary undertaking. The first step would be to speak to your company and ask them for a copy of a testing report for the office. This is legally required by Chinese law and looks mainly at chemicals like formaldehyde and benzene, giving either a pass or fail rating along with the tested value. This report will not give you the full picture as it may have been done years ago and does not look at PM2.5 or CO2. Additionally, we have found that quite a few companies never undertake this basic testing as enforcement is quite lax. Whether it be the outdated data, lack of PM2.5 or CO2 testing, or due to an absence of any testing whatsoever, this presents a good opportunity to ask for a professional testing company to come in and provide a full report and monitoring services to provide a complete and accurate picture of the work environment. As a business owner or GM this is not a time when you want to look at saving on costs by not testing or trying to \u201cself-test\u201d with gadgets purchased off of Taobao. It is becoming increasingly common for informed employees to call out their companies for lack of testing and, if there are actually problems with the space, even threatening lawsuits for providing an unsafe work environment.<\/p>\n
Chris: At the moment the majority of our customers are Fortune 500 companies, almost all western. We do work with a few Chinese tech companies like Tencent (QQ, WeChat) and Alibaba, but these are usually the exception to the rule. One of the reasons we see Chinese tech companies using our services is that they are often competing directly with their western counterparts to hire the best employees. Besides salary, a comfortable working environment is usually a top priority for anyone spending 10 or more hours a day in an office.<\/p>\n
<\/p>\n
For any company thinking about this type of service it will consider how much money needs to be spent and how much benefit will it receive because of this investment. The money spent is easily calculated. What is more difficult to determine are the benefits that will be accrued as most of these cannot simply be measured in terms of hard currency. How much is it worth that someone chose to work here because of the Indoor Air Quality? How much is it worth that people are staying because of it? How much is being saved by having fewer sick days? How much is it worth that people are more productive with cleaner air and lower levels of CO2? How much is it worth if this system can be used as a marketing tool to give people a better impression of the company? The list goes on and on, but the main takeaway is that most of the value in doing something like this cannot be measured with a number, but needs to be looked at in the greater scheme of things over months and years.<\/p>\n
Graeme: This is perhaps the most common misunderstanding. AQI stands for \u201cAir Quality Index\u201d and normalizes all air quality into a 0-500 scale, with 0 being the best and 500 being the worst. This was popularized by the US Embassy and is used most often because it is easy to remember and does not have units. API or \u201cAir Pollution Index\u201d is used by the Chinese government and is a similar index, but categories correspond to different levels of pollution, so the two cannot be compared.<\/p>\n
Finally, mass concentration refers to how much weight in micrograms of a certain size of particulate in a cubic meter (ug\/m3). Of these, the mass concentration is most useful because it is directly correlated to health standards. The WHO sets 25 ug\/m3, the US EPA sets 35 ug\/m3, and China sets 75 ug\/m3 as the maximum limit for healthy air over a 24hr period.<\/p>\n
Importantly, the China AQI index is lower than the US one, and therefore categorzies the same pollution levels in mass concentration to a less serious health status. The following pictures illustrate that at the same mass concentration (59ug\/m3) the Chinese index rates it as \u2018Light\u2019 whereas the US one rates it as \u2018Unhealthy\u2019. Therefore, we advocate for using mass concentration in order to make like-for-like comparisons.<\/p>\n
The following image also helps summarize the differences between the indexes:<\/p>\n
<\/p>\n
Chris: While this has changed quite a bit over the last few years, the majority of residents do not regularly check either PM2.5 or AQI readings. Those that do check tend to be younger individuals who own smart phones.<\/p>\n
The standard for most people is still looking out the window at the sky and taking a guess. If the sky looks particularly gray or smoggy they will assume it\u2019s a bad day. This isn\u2019t to say that their behavior will change in how they handle the pollution, simply that they assume it\u2019s a bad day.<\/p>\n
The problem with this is that it is simply an unreliable way to gauge pollution levels outside. There are days where there are blue skies but pollution levels will be unhealthy even by China\u2019s lax air pollution standards. On the flip side there will also be days where one would guess pollution levels would be high because of an overcast sky but in fact levels are low and maybe only dangerous for people particularly sensitive to pollution.<\/p>\n
<\/p>\n
An even larger problem, and this is the area in which we operate, is indoor pollution. Most people in Chengdu operate under the completely false belief that if you are inside you are fine. This is not the case. Yes, most time being indoors offers a level of protection from the outside air, but we have seen plenty of instances where indoor levels of PM2.5 are far greater than outside. PM2.5 particles are brought indoors through open windows and doors, building leakage and on peoples clothes and shoes. Unless removed by using a HEPA vacuum or a wet mop these particles will stay in the indoor space, settling on the ground, on top of surfaces and suspended in the air.<\/p>\n
Through real-time and long-term monitoring that we have done at about a dozen Grade A office buildings we will quite often see indoor PM2.5 levels much higher than outdoor levels during the hours of 7pm to 7am and on weekends. The reason for this is threefold:<\/p>\n
Through monitoring data, we have found that the protection level from a building can vary greatly and can offer anywhere from 20% to 50% protection on its own. In a residential building you will most likely have a low level of protection from the old walk up apartments (6-7 story gray buildings) of around 20% and up to 40% protection in high end apartments that are new. In an office building things are sealed tighter and protection levels may be in the 30% to 50% range based on the age of the building and the grade of office.<\/p>\n
This reduction is critical, but all too often people are sabotaging this by having windows open, smoking indoors and not cleaning properly. It does not matter if you are in the nicest office building in the city, if you are not cleaning properly PM2.5 levels will remain high in the space.<\/p>\n
While not technically pollution in the traditional sense, most people do not tend to think too much about the materials and furniture around them. Yes, when a renovation has been recently completed most Chengdu residents are very concerned about odors and chemicals. The typical approach taken means leaving the space left unoccupied for months or a year and involves the rinds of various fruits and placing them around the space with little carbon bags and maybe even coffee grounds. This is not an effective approach as it wastes time and accomplishes very little (though carbon pouches can be effective in small enclosed spaces such as cabinetry). However, a year or two after completion there will be little attention paid to this. Paint, carpet, flooring, glues, furniture and a host of other items can continue to \u201coff-gas\u201d and put harmful chemicals into the air for years to come. If there is no odor it doesn\u2019t mean there isn\u2019t a problem. If there is an odor, it does not mean that there is a problem: it depends on the odor threshold of the target chemical and the related exposure threshold as well as the olfactory detection disparities of individuals. That is why IAQ is a complex mix of people perceptions, human behavior and building operations and mechanical systems. So when it comes to indoor air pollution a well-planned investigation is required and not just a round of air tests.<\/p>\n
Graeme: Any official outdoor monitoring station that is maintained by a Chinese environmental monitoring station is pretty accurate and can be used as an outdoor reference. The US Consulate also maintains an outdoor monitoring center, but this should not be used if there is a closer one. Generally, readings are fairly representative if within 1-2 kms. If beyond that, consider setting up a local outdoor monitoring center.<\/p>\n
<\/p>\n
Graeme: Hourly outdoor air quality data is now available widely throughout China. This data is republished by many different free applications. We favor apps that allow you to see historical trend data, and those that publish both AQI and mass concentration. Our favorites:<\/p>\n
Graeme: There are a lot of different air quality monitors out on the market. A handheld device that purports to measure PM2.5, for instance, can range from a 500 rmb domestically produced model to an imported model from the US that runs 30,0000 rmb. The main difference is the experience and reliability that usually translates to data which is accurate and stable, across a range of likely conditions.<\/p>\n