Volunteers help installing roadside test tube sampling

Thank you for the great support from our volunteer team!

With the help of volunteers, the diffusive samplers of the NO2 Diffusion Tube Action were set up around Shum Shui Po area on 19 October.


Volunteers were divided into groups and they installed the tubes near school campus, parks, bus stops and crossroads for 2 weeks.


The tubes were collected and these street samples were ready to be sent to UK for further analysis. The diffusion data would be used to find out the roadside nitrogen dioxide levels.



More about NO2

When fossil fuels such as coal, oil, gas or diesel are burnt at high temperatures, Nitrogen Dioxide (NO2) forms. Marine vessels, power generation and road transport are the top three sources of Hong Kong’s nitrogen oxides emissions.

As an air pollutant, NO2 has several correlated activities. At short-term, concentrations exceeding 200 μg/m3, it is a toxic gas which causes significant inflammation of the airways. NO2 is also the main source of nitrate aerosols, which form an important fraction of PM2.5 and, in the presence of ultraviolet light, of ozone.

Epidemiological studies have shown that symptoms of bronchitis in asthmatic children increase in association with long-term exposure to NO2. Reduced lung function growth is also linked to NO2.


*NO2 Diffusion Tube Action is part of the “Let Our Children Breathe” program.

Story posted on
6th Nov, 2019


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