2013 January 12 Saturday
Beijing Air Quality Highly Toxic
The US embassy in Beijing has an air quality monitoring device on its roof. The scale is supposed to stop at 500 with anything above 300 considered hazardous. The US embassy just reported 755. It has since gone higher than the NYTimes reported. From the Beijing US Embassy's air quality twitter feed here's a higher peak at 845 or is it 755? Anyone know how to read it?
01-12-2013 20:00; PM2.5; 886.0; 755; Beyond Index
The 755 might be the ozone number.
Do not live in Beijing. If you find the career advantages of some time in Beijing to be too great to turn down get a really good air filtration system. The hard part is getting a system that can remove the smallest particulates. The smaller they are the harder they are to remove.
One wonders what Western corps do about their air filtration and whether their employees get air filtration systems at home.
What I'd like to know: how well can air filtration systems filter out smaller particulates? How much dangerous stuff can get thru a HEPA filter?
By Randall Parker at 2013 January 12 09:14 PM
So I used to work at a medical-scientific institution which used laboratory mice (some immune-compromised) and fruit flies in a locality well-known for severe smog. To guard the health of the experimental organisms (the little critters are surprisingly sensitive) and to prevent smog poisoning from confounding the results of medical experiments, it was necessary to filter the air in the vivariums. It is possible but costly to filter out even very small particulates (like diesel soot), oxides of nitrogen, VOC's, ozone, etc. The better the filters, the more electricity it takes to force air through them, and the more it costs to maintain and replenish the filters (much of the gunk is adsorbed using activated charcoal after particulates are removed partly by electrostatic precipitation and partly by mechanical filtering through small-pore membranes). Of course it was necessary to maintain positive pressure of filtered air in the building(s) to exclude unfiltered air, so that meant sealed windows and gasketed doors with a "snow lobby" type arrangement.
Visitors accustomed to the odor of smog used to complain that the filtered air "smelled funny," because it did not smell at all!
So if you want effective air filtering, you can have it-- it will just cost a lot to set up and run. Like, I dunno, ten times a normal air-conditioning bill? If there is too much CO2 in your air (not common) you will have to spring for costly chemicals to absorb it because you cannot catch CO2 on activated carbon.
Smaller particles should be more vulnerable to electrostatic air filtration mechanisms. But I think that before investing in a killer air filtration system that eliminates all particles and toxins from your air, it would make sense to spend time on a cost-benefit analysis and figure out which of the contaminants and toxins are really likely to kill you. Maybe reducing particulates by 95% would be sufficient.
So my cousins have 3 air purifiers in their 8 room apartment in a pretty much hermetically sealed fully air-conditioned modern high rise. They drink imported bottled water from a water cooler in their utility room and keep a second bottle in the bathroom for brushing teeth and bathing their child. They eat imported food mostly from New Zealand. My impression is that in addition to all the ex-pats the local rich and powerful also live this lifestyle or go more opulent. Obviously the Hu Tong (sp?) dwellers are taking it on the chin but it you are from a g-20 place and you are being sent to China it is to live the 1% lifestyle.
HEPA filters don't seem to do much in a non-sealed room. An easy airborne dust detector is a strong flashlight in a dark room. I could not tell any real difference in air quality in a room with the filter running and not running except in the immediate vicinity of the filter. One time I collected a bunch of dust particles using Scotch tape to pull it off of horizontal surfaces. What I found was that the vast majority of the particles were carpet fibers. Another interesting thing I found was that the outside air had noticeable fewer particles than the inside air on a typical day.
I think the IQ Air brand of air filters will do the job for an affordable price. I've got a Honeywell HEPA unit. But not living in a severely polluted place. Maybe I'll eventually pop for the IQ Air unit anyway.
Wow, radical. A friend in Beijing tells me her hotel doesn't even have an air filter. I am worried for her. She wears a mask when she goes outside. Beijing is on my list of cities I do not want to visit. I wonder how Shanghai's air quality compares.
Imported food: sounds expensive.
Imported water: You can get pretty good water filters. That doesn't seem necessary.
Was the filtering unit up to the size of the place? Was it high enough in quality? They differ quite a bit in how well they work. You can find independent ratings. I think Consumer Reports may have rated some.
Carpet fibers: sounds like a reason to not have a carpet. My place has a carpet. But I wish it didn't.
Hopefully this is not too far off topic but one thing I have always wanted to do is build a house with a controlled atmosphere. The house would be kept at a slight positive pressure from a fan pulling in filtered outside air. The house would have wood and tile floors instead of carpeting.
If the house were sealed well enough, it would be possible to warm or cool the incoming air with exhaust air through an air to air heat exchanger, thus saving on the energy costs. I am surprised that home builders have not seized on the opportunity to build "allergy free" homes. Maybe I had an original idea. Or, maybe its been tried and it didn't work too well.
"Was the filtering unit up to the size of the place? Was it high enough in quality? They differ quite a bit in how well they work. You can find independent ratings. I think Consumer Reports may have rated some."
My filters are Honeywell units and they do work. I ordered the units appropriate for the room sizes. In my case, the dust sources are obviously bypassing the filter. Most of my dust comes from the carpet. Just the slight airflow over it is enough lift the dust from it. This dust is mainly synthetic fibers. Take away the carpet fibers and the filters may be doing a good job. I don't know. I think if a person puts a filter in close proximity to their work area and their bed they will get some benefit.
"If the house were sealed well enough, it would be possible to warm or cool the incoming air with exhaust air through an air to air heat exchanger, thus saving on the energy costs. I am surprised that home builders have not seized on the opportunity to build "allergy free" homes. Maybe I had an original idea. Or, maybe its been tried and it didn't work too well."
It's a good idea. Residential HVAC, in the USA at least, is a joke. People don't understand or care about ventilation and air quality so they only want to pay as little as possible. (while spending the money on more floorspace for example)
"a pretty much hermetically sealed fully air-conditioned modern high rise."
I wonder what the O2 and CO2 levels are in their apartment. a pretty much hermetically sealed fully air-conditioned modern high rise.