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Air Pollution|Concentrations of many pollutants rebound under the epidemic, ozone concentration is the second highest in 10 years

2022-01-28T09:22:43.178Z


Hong Kong is shrouded in haze from time to time, and the air quality varies from time to time. The Environmental Protection Department announced today (28th) the air quality in Hong Kong in 2021, indicating that the overall air quality has a clear trend of improvement. The EPD described the air quality last year as


Hong Kong is shrouded in haze from time to time, and the air quality varies from time to time.

The Environmental Protection Department announced today (28th) the air quality in Hong Kong in 2021, indicating that the overall air quality has a clear trend of improvement.

The EPD described air quality last year as "the best in the past 10 years".

However, the concentration of many pollutants rebounded significantly compared with 2020 last year, and also exceeded the final WHO target.

The nitrogen dioxide (NO2) content was 2.6 times higher than the WHO standard.


In addition, the air pollution at roadside monitoring stations is seriously exceeding the standard, and the exceeding standard in Mong Kok is nearly doubled.

The ozone concentration of pollutants has also increased compared with last year, and the ozone concentration of general monitoring stations is the second highest in 10 years, only second to the level of 2019.

The Environmental Protection Agency explained that the ozone concentration is still on the rise for a long time, mainly due to the regional photochemical smog problem.


▼Last year's 7.23 multi-regional air quality health index exploded▼


The Environmental Protection Department announced today that the concentrations of air pollutants nitrogen dioxide (NO2) and ozone (O3) increased last year compared to 2020, although respirable suspended particles (PM10) and fine suspended particles (PM2.5) were recorded at general monitoring stations. Concentrations are the same as in 2020, but roadside monitoring stations are up.

In terms of nitrogen dioxide, the average annual concentration of nitrogen dioxide at general monitoring stations is 36 micrograms per cubic meter, an increase of nearly 10% over last year. Although the data is in line with the local target of 40 micrograms per cubic meter, it is 2.6 higher than the final target set by the WHO. times.

As for the nitrogen dioxide concentration at the roadside monitoring station, it exceeded the local target, reaching 70 micrograms per cubic meter.

Liang Qiming: Excessive nitrogen dioxide is mainly due to road vehicle emissions

Leung Kai-ming, assistant director of the Environmental Protection Department (air quality policy), pointed out that the concentration of nitrogen dioxide at roadside monitoring stations exceeded the standard, reflecting that the main source was local emissions, and he believed that the main cause was road vehicle emissions.

In addition, ships are also the main source of emissions, so nitrogen dioxide in areas such as Tsuen Wan also exceeds the standard.

When asked if there was still an epidemic last year, why did the nitrogen dioxide also exceed the standard?

He responded that nitrogen dioxide is mainly due to automobile problems, so various electric heavy-duty vehicles, including double-decker buses, will be tested in the next 2 to 3 years.

He also emphasized that the impact of the epidemic in Hong Kong in the first half of 2020 is greater than that of the whole of 2021, and the air quality in 2021 will still improve compared to 2019. , scientifically, it is meaningless to look at short-term factors.”

Tap Mun has the highest ozone concentration in Hong Kong

In terms of ozone, the average annual concentration of ozone at general monitoring stations last year was 55 micrograms per cubic meter, an increase of nearly 6% over last year and the second highest in 10 years. The average annual ozone concentration at roadside monitoring stations was 31 micrograms per cubic meter.

Liang Qiming explained that ozone is formed by photochemical reactions of nitrogen oxides (NOx) and volatile organic compounds (VOC) in the air under sunlight.

As the emission of vehicles in Hong Kong continues to decline, the reaction between nitric oxide and ozone has been reduced, so the consumption of ozone has also decreased, and the concentration of ozone has shown an upward trend.

Leung also pointed out that the ozone concentration in Tap Mun is the highest in Hong Kong, reflecting that ozone is a regional problem.

He predicts that ozone will continue to rise for a long time, mainly due to the unresolved problem of regional photochemical smog. "If one day all roadside electric vehicles are converted to zero emission, the roadside (ozone concentration) will continue to rise to the tower gate. That kind of thing is bound to happen, so don't make a fuss about it."

He stressed that ozone has no major health risks and should be a short-term indicator.

When asked about the distance between the air quality targets in Hong Kong and the final targets of the WHO, Leung emphasized that the current standards have reached the mid-term targets of the WHO, but because there are still automobile emissions, he has repeatedly stated that "no city in the world has reached the final targets. ".

As for the review of air quality objectives, the Chief Environmental Protection Officer (Air Science) of the Environmental Protection Department, Liu Wanpeng, pointed out that it depends on the implementation of various blueprints and the regional air quality.

He bluntly said that he is very optimistic about the improvement of air quality in Hong Kong, and "targets the ultimate goal of the WHO".

Air Pollution 2021|The concentration of nitrogen dioxide on the roadside exceeds the limit by 6 times. The concentration of suspended particulates in Tuen Mun is the highest in Hong Kong. CUHK Yan Honglin: To reduce emissions, we must change our travel habits. We should assess the health risks of different air pollution levels. At the end of this year, the proposed route will be added. The government will update the air blueprint within the year, and the group will approve the emission reduction work. It will be very slow to advocate air pollution black spots.

Source: hk1

All news articles on 2022-01-28

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