Photo: Wikimedia Commons
Photo: Wikimedia Commons

A green group has warned that ozone concentration has hit the highest level in 20 years in Hong Kong and a government action plan to curb roadside pollution is unlikely to hit its 2020 targets.

The Clean Air Network compared roadside pollution data from the first half of this year with the previous two years in its latest half-yearly air quality review and found a generally rising trend in the average concentration of ozone in Hong Kong.

In the first half of this year, it reached an all-time high of 46.92 micrograms per cubic meter, almost double the level in 1997. The concentration of ozone is more severe in the eastern side of the city, Ming Pao Daily News reported.

Tap Mun, an island in northeastern Hong Kong, recorded the highest ozone concentration at 74.37 micrograms per cubic meter.

Ozone can lead to shortness of breath, coughing and inflamed airways.

Meanwhile, nitrogen dioxide (NO2), the main pollutant generated from transport, ranks the highest in Kwai Chung, Sham Shui Po and Tsuen Wan.

The green group analyzed data from three roadside stations in Central, Causeway Bay and Mong Kok and they showed reductions in concentrations of NO2, PM2.5 and PM10 (measures of particulate matter) from the year before.

However, the downward trend was not quick enough to meet projections for 2020 roadside pollution targets set in 2013 by the government’s Clean Air Plan. That year, the government set the target of a 40% reduction of 2012 roadside pollution levels by 2020.

The green group cited the Hedley Environmental Index from the University of Hong Kong’s School of Public Health, claiming that unhealthy air caused 867 premature deaths in Hong Kong between January and June of this year and inflicted an economic loss of HK$10.4 billion (US$1.32 billion).

The group urged the government to make a new action plan projecting to 2020 and onward to improve both ambient and roadside pollution.