One cannot judge whether it is sandstorm or smog by visual inspection.
The harmful effects of the two to health are quite different. Sandstorm consists of larger particles (usually bigger than 10 micron), which can be easily filtered out.
In smog the harmful effect comes from ozone and PM2.5 (particles of size less than 2.5 micron) which cannot be handled by filtration.
PM2.5 comes mainly from industry and ozone cannot be produced by sandstorm.
Read this, it is mainland website: http://www.ecns.cn/cns-wire/2014/05-22/115420.shtml
我們把地球當敵人，9 項居住指標已超標 4 項
Dear Chan Sir,Chanlunlun 寫:Yes we may be destroying our environment but no in such a degree that we will soon kill our planet. Earth is still in good shape. It;s a pity that mass media always exaggerates in order to attract eyeballs.lightning 寫:！點解又改咗完全相反嘅意思？
人類活動破壞環境連4歲小朋友都知，點會唔岩？
Take Peking for example, the so called "smog" may not all entirely originate from air pollution. Actually quite a part of "smog" comes from water vapor in air and tiny sand particles blowing in from northern deserts. They are part of the nature.
Of course pollution plays a part, but not as a terrible part as some movie/media said.
From the discussion below:
http://aqicn.org/faq/2015-02-08/visual- ... -to-hanoi/
(Hanoi user suspects the AQI number in Hanoi much better than that of Beijing, given similar visibility reduction observed.) I think it is safe for us to say, at least in Hanoi, the water droplets are EXCLUDED from PM calculation.
I personally don't see any technical troubles to do so, dozens of methods can. One of the simplest I was wondering is just heat the air sample a few degrees above dew point can evaporate the water droplets into water vapor, which is gas itself, should not be detected as micro-meter size particles by any PM measuring means.
No matter whether the air pollution problem is caused by smog or dust particles.Air pollution is still a problem in many other urban areas around the world besides the Mainland China.Although I 'm not always fully accept to what the mass media say but at least I definitely don't believe to somebody say air pollution is not a problem especially in the Mainland China 's urban cities. It is obviously opposite to the real situation as the links you share are point out to the air pollution problem in urban cities.
To sum up. Air pollution is really a problem in the Mainland
China as everybody known and it is caused by human activities
at a certain degree.
To sum up. Air pollution is really a problem in the Mainland
China as everybody known and it is caused by human activities
at a certain degree.
The news we heard from TV and official meteorological reports is not just based on visual inspection but from the precise data they
have collected.
bbsdma 寫: Dear Chan Sir,
From the discussion below:
http://aqicn.org/faq/2015-02-08/visual- ... -to-hanoi/
(Hanoi user suspects the AQI number in Hanoi much better than that of Beijing, given similar visibility reduction observed.) I think it is safe for us to say, at least in Hanoi, the water droplets are EXCLUDED from PM calculation.
I personally don't see any technical troubles to do so, dozens of methods can. One of the simplest I was wondering is just heat the air sample a few degrees above dew point can evaporate the water droplets into water vapor, which is gas itself, should not be detected as micro-meter size particles by any PM measuring means.
Sorry!I can't help to give some comments again.
The information you give seems to be no relationship to what the main topic talking about and it can not reflect anything from real.
誰在線上
正在瀏覽這個版面的使用者：沒有註冊會員 和 15 位訪客