HCMC enjoys good air quality Tuesday

The air quality index (AQI) in Vietnam’s biggest city during Tuesday morning stayed at an average level of 33, according to the Switzerland-based air quality monitoring facility, IQAir AirVisual.

For the AirVisual's AQI, the higher index means worse air pollution.

An index of 33 puts HCMC's air quality in the "good" range, which means the air quality is "satisfactory", and there is little or no risk from air pollution.

By around noon, the index rose to "moderate" range, when sensitive people are recommended to avoid outdoor activity.

AirVisual measured the average air quality level of the city at 49 on Monday, which was also in the "good" range.

AirVisual measured the city's PM 2.5 concentration on Tuesday morning at 8µg/m³, which is 1.6 times the WHO annual air quality guideline value, and by noon at 13µg/m³.

PM2.5 is defined as ambient airborne particulate that measures up to 2.5 microns in size, just a fraction of the width of a human hair. Their microscopic size allows these particles to be absorbed deep into the bloodstream upon inhalation, potentially causing health effects like asthma, lung cancer, and heart disease.

Exposure to PM2.5 has been linked to negative health effects like cardiovascular disease, respiratory illness, and premature mortality.

American site AccuWeather rated HCMC's air quality as "excellent" on Tuesday with an AQI of 17.

It measured the PM2.5 level in the city at 9µg/m³, saying the air quality is ideal for most individuals and that people should "enjoy your normal outdoor activities."

HCMC has entered the dry season, with the highest temperature in the day rising to 34-35 Celsius degrees.

The AQI of Hanoi on Tuesday stays at 98, within the "moderate level" as measured by AirVisual, which recommended people to "close window to avoid dirty outdoor air" and sensitive groups to reduce outdoor exercise.

It measured the capital's PM2.5 at 34.6µg/m³, which is 6.9 times the WHO annual air quality guideline value.