Visual recognising the Air Quality Index - a case applied to Hanoi

Posted on February 8th 2015
Share: aqicn.org/faq/2015-02-08/visual-recognising-the-air-quality-index-a-case-applied-to-hanoi

Earlier this week (of February 2015), we got several inquries from Hanoi citizen wondering about the Air Quality Index which was displayed on the Hanoi page (city/vietnam/hanoi).

The main reason for the inquiry was that the Air Quality Index displayed on the World Air Quality Index project was around 50 (green AQI) level, while the outdoor visibilty in Hanoi looked like this:


For reference, on the same day in Beijing where the Air Quality Index in Beijing was arround 180 level, the visibility looks like this picture:



One interresting comment on the above picture for Beijing is that the right-part of the picture is having a worst visibility than the left part. This is actually completely normal, pollution is not always uniform, and depending on the wind direction, one part of the city can have relatively good air quality while the other part can be much worse.

oOo

When comparing the visibility for Hanoi and Beijing (see pictures on the right for a comparitive zoomed view), there is no doubt that Air Quality for both cities is at similar level, and, for sure, than if the Beijing AQI is about 180, then it is very likely than Hanoi AQI is much higher than 50.

However, please note that, sometimes, the poor visibility is due to high humidity rather than air pollution (smog). The easiest way to differenciate between humidity and smog is by checking the haze color. If it is yellow or grey, then very likely this is due to smog. But if it is a clean white, then most likely what you are seeing is water vapor (i.e. humidity).

In case you still have some doubts, you can also refer to the Air Quality forecast for your region: The forecast always starts with the current day, so you can check from the first frames of the forecast animation the AQI level for your city.

oOo

When you notice such issue with reported Air Quality - then, please, drop us an email and we will do the necessary to check, verify the data, and contact the relevant local EPA to get the issue fixed.

The problem with Hanoi actually happened to be an issue with the monitoring station itself emitting too low values. Once the problem was well identified and acknowledged, it took no time for the local Hanoi EPA (Environment Protection Agency) to fix the issue and get the monitoring station working normally again. Many thanks again to the Hanoi EPA for the effort and quick action.


Click here to see all the FAQ entries
  • Nitrogen Dioxyde (NO2) in our atmosphere
  • Ozone AQI Scale update
  • Kriging Interpolation




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    대기 품질 및 환경 오염 측정에 관하여 :

    대기 품질 지수 단계에 대하여

    AQI지수구분구간의미
    0 - 50좋음대기오염 관련 질환자군에서도 영향이 유발되지 않을 수준
    51 -100보통환자군에게 만성 노출시 경미한 영향이 유발될 수 있는 수준
    101-150민감군영향환자군 및 민감군에게 유해한 영향이 유발될 수 있는 수준
    151-200나쁨환자군 및 민감군(어린이, 노약자 등)에게 유해한 영향 유발, 일반인도 건강상 불쾌감을 경험할 수 있는 수준
    201-300매우나쁨환자군 및 민감군에게 급성 노출시 심각한 영향 유발, 일반인도 약한 영향이 유발될 수 있는 수준
    300+위험환자군 및 민감군에게 응급 조치가 발생되거나, 일반인에게 유해한 영향이 유발될 수 있는 수준
    (Reference: see airkorea.or.kr)

    대기 품질과 오염에 대해 더 많은 것을 알아보려면 위키피디아의 공기품질 문서(영어)을 보거나 공기 품질과 건강에 대한 AirNow 가이드(영어)를 참조해보세요.

    베이징 의사 Richard Saint Cyr MD의 건강 관련 팁을 보려면 www.myhealthbeijing.com 에 블로그를 확인하세요.


    Usage Notice: All the Air Quality data are unvalidated at the time of publication, and due to quality assurance these data may be amended, without notice, at any time. The World Air Quality Index project has exercised all reasonable skill and care in compiling the contents of this information and under no circumstances will the World Air Quality Index project team or its agents be liable in contract, tort or otherwise for any loss, injury or damage arising directly or indirectly from the supply of this data.



    설정


    언어 설정 :


    Temperature unit:
    Celcius