How does the outdoor air quality AQI look?

The health hazards of air pollution have been defined by the International Agency for Research on Cancer IARC as the first-level carcinogen (see: [We should prepare for cancer earlier】), and was put on the top of the agenda by the World Health Organization. As ordinary people, how can we help ourselves prevent health hazards? The author believes that understanding air quality is the first step.

According to the Environmental Protection AgencyAir Quality Monitoring Network, Which is forAir quality index(Air Quality Index, AQI) Is defined as follows:

According to the monitoring data,Ozone in the air (O₃),Fine suspended particles (PM_2.5),Suspended particles (PM₁₀),Carbon monoxide (CO),Sulfur Dioxide (SO₂) andNitrogen Dioxide (NO₂) Concentrations and other values are converted into the sub-indicator values of different pollutants based on their degree of impact on human health, and thenThe maximum value of each sub-indicator on the day is the air quality index value (AQI) of the station on the day.

Next, the Environmental Protection Agency will give different risk levels and colors according to the level of indicators, and give corresponding activity recommendations. The risk levels are as follows:

From the above we can know:

Air quality index AQI ≠ PM 2.5

That is,Even with the same AQI value, the pollution type it represents may be different. Different regions will have different common air pollution (due to different sources of pollution) due to factors such as the type of industry, traffic conditions, geographical location, etc. However, generally speaking, fine suspended particulates (PM 2.5) and suspended particulates (PM 10 ) Is still the most common factor affecting AQI.

If Taiwan’s air quality is defined as a “good” standard for PM (Particulate Matter), it willThe World Health Organization's recommendations on outdoor air qualityFor comparison, although there is a partial gap, it is still close; on the whole, the long-term goal isReduce the annual average of fine suspended particles (PM 2.5) and suspended particles (PM 10) to 10 μg/m³  And 20 μg/m³ .

On average, in Taiwan’s metropolitan areas, even in northern Taiwan metropolitan areas with better outdoor air quality, PM is still oftenNot goodLevel.

So I suggest that if you are used to using mobile phones, you canDownload the app about air quality monitoringFor those who are unfamiliar, consider using a computer to check today’s air quality when going out to decide whether to wear a mask (generally masks cannot be blocked by 100%, but only have the effect of reducing exposure), or change the activity schedule (such as: When the air quality is poor, avoid outdoor exercise schedules).

[The author’s small step] I believe everyone has seen that when the fog is heavy, there will be obvious light and shadow trajectories under the light of car lights or flashlights, and the same principle can also be applied to simple evaluationAerosolThe air concentration. If you are walking on the road when it is not raining and you look up during the day, the sky seems to be enveloped.Evenly distributed haze, Or see it at nightObvious light and shadow trails appear under the street lights, Then it usually represents the air of the momentAerosolThe concentration is high, it is recommended to wear a mask!