Hong Kong enjoys a breath of fresh air but it’s not enough to meet annual quality goals

Lower concentrations of harmful pollutants were recorded last year, including the tiny particulates that can penetrate deep into the lungs – but roadside- ­dominant nitrogen dioxide ­remains a headache for the city, with most figures failing annual air quality targets.

And while ambient concentrations of hazardous ozone fell for the second consecutive year, they are proving stubbornly hard to cut having increased 15 per cent since 1999.

The preliminary air quality ­data for 2016 was released by the Environmental Protection Department yesterday.

At roadsides, concentrations of respirable suspended particulates (PM10) dropped by 15 per cent, fine suspended particulates (PM2.5) by 12 per cent, and ­sulphur dioxide (SO2) by 10 per cent.

Similar drops were recorded at general stations. Fewer hours and days of high health risk air were ­recorded at both ambient and roadside stations last year.

But although roadside concentrations of nitrogen dioxide (NO2) – a product of fuel combustion – fell by 17 per cent, the ­average annual concentration of 82 micrograms per cubic metre of air was still more than double the annual air quality objective target of just 40.