3 hour reading is already bad. 24 hour reading is plain evil.
How much does a pm2.5 reader costs?
Well, that minister who said that the 24-hr PSI reading is more important has a point too since the effects are also cumulative in nature. Just that personally it really smoothen things out too much and for this year 2014 kind of ON/OFF haze it really serves no purpose. Healthy individuals I guess 99.9% no issues, but not for those in the sensitive group, including pregnant women (ie nobody in her right mind would want to even be a passive smoker).
For me I am quite ngeow for 2014, my youngest kid is just 9 months old, just luckily not below 6 months when development + body resistance is most critical. In March there was a short period of 1 week haze though, even with an air purifier in the room, he occasionally sneezed more when he was brought out into the living room.
March 2014 24-hr PM2.5
Cumulative in nature...
It's been 1 month already, the light haze started since Sep 1st and for most of the time....offhand, i'd guess about 70-80% of the time the 24-hr PM2.5 hovers just slightly below the Unhealthy limit for the Sensitive group? There were a few spikes, they never showed up on NEA 3-hr PSI figures, they showed up on my PM2.5 monitor. Unfortunately it's not an accurate one, I could only derive relative readings/comparisons. But yes they showed up alright + backed up visually (not the other way round).
Right now, it reads 24-hr PM2.5(µg/m3) 39 ug/m3 for West, which reflects as AQI PM2.5 of 109 (and actually still rising as of now even though Batam became visible since 3 hours ago). AQI is directly comparable to what China is using, which is the same AQI.
Pollutant Concentrations
For comparison, Beijing's 24-hr PM2.5 (today) is just 37.62ug/m3. The only difference is that it recorded the spike for 1-hr PM2.5. Just now for 2-hrs, NEA published did not, though the spike was not a lot.
1-hour PM2.5: 73.92μg/m3,
24-hour PM2.5: 37.62μg/m3.
Last weekend before F1 or during F1 hrs (depending on which part of the island you are located, the small but dense cloud does take time to travel even though SG is small), somebody else posted in another thread a measured a peak of 250 ug/m3 and nominally 160-170ug/m3 of PM2.5. That works out to be an AQI of 300 for the peak and about AQI 200 nominally.
That was by a BRAMC PM2.5 air quality monitor, it's not gonna be accurate, but it does give you a decent idea.
PM2.5 monitors are cheapest on taobao. You'd need to do international forwarding via the official forwarders. There is a dedicated taobao support thread here in EDMW....lots of help there.
The guy in another thread used this BRAMC PM2.5 air quality monitor. This is LED based, and also has either a formaldehyde sensor in it or a VOC/Volatile Organic Compound sensor in it.
BRAMC
Other models, just for info
pm2.5
However, I would recommend a laser based sensor, the cheapest run about rmb700.
http://detail.tmall.com/item.htm?sp..._id=&am_id=&cm_id=140105335569ed55e27b&pm_id=
But seriously, also no point getting a PM2.5 monitor now, since the $$$ is better spent on getting air purifiers and the haze is ending. Unless your bonus high 5-figures gao gao.
For healthy persons who are not allergic/susceptible to extended light haze, then it's really a moot point.
I guess such "gadgets" are really useful for those who are chronic asthmatic esp the young kids/babies. I know someone who has a neubiliser on standby 24/7 now coz she went into A&E a few times last year.
It's no joke for some.
