CAN Impact 2020 - Air Monitoring and Analysis


We have enjoyed more clean air days in Hong Kong over the past few years. According to the Hedley Environmental Index, the total number of clear days is increased from 109 to 214 between 2016 and 2020. CAN is excited to see the air quality has improved this year but the increasing ground-level ozone pollution becomes an alarming threat to our health.

Clear Days 2016-2020

Pandemic and Air Quality

2020 is the year of pandemic. The global economy, outbound travel and public health systems have been badly affected by the COVID-19 pandemic and lockdown. The coronavirus seriously hit the quality of health care and disrupts our social life worldwide.

Meanwhile, it seems that the nature gets a break from human activity due to the coronavirus pandemic. A dramatic decline in pollution level is observed in many big cities. The change in air quality has a direct link with the decrease in traffic flow and economic activity.


Analysis of air quality in Hong Kong

Hong Kong followed a similar pattern. Clean Air Network analyzed air data collected by air pollution monitoring stations operated by the Environmental Protection Department. Roadside air pollution level reached the lowest in the first quarter compared to the same period in the last four years (2016 -2020). More detailed analysis can be found on our first half of 2020 Air Quality Review.

However, the city experienced a rebound of roadside air pollution from July to September 2020 after the social distancing policies were eased. It is a worrying trend because a recent study has found that tiny air pollution rise linked to an 11% increase in death from COVID-19. Furthermore, the ozone pollution level has reached a 20-year high.


NO2 Measurement Report

We conducted NO2 measurement projects in Central District, Sham Shui Po and West Kowloon over the past year. The findings showed that the NO2 level recorded at the bus stops mainly exceeded the annual safe level recommended by WHO. Commuters and students who queue at the bus stops are at risk as they are exposed to the dangerous level of roadside air pollution daily.

CAN Impact 2020 - Air Monitoring and Analysis SSP Report 2020March

Central Roadside pollution NO2 measurement report (March 2020)


Clean Air Paws Researcher

With the support from Paws Hero, we are happy to team up ten lovely furry friends being our Paws Research Team. The paws researchers help us collecting air data while walking in different routes in their neighborhoods since November. The measurement would raise public awareness of air pollution and its health threats of both human and animals.

But the global pandemic is teaching an expensive lesson in public health. Environmental problems can make us vulnerable to diseases and disasters. If we don’t make any changes to avoid pollution and environmental destruction, there is a huge cost to our economy and our lives.


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Story posted on
26th Dec, 2020


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