The ozone level in Tung Chung has worsened in the last five years, but the presence of all other major pollutants has declined, according to government figures.

Air quality data released to Legco today show ozone levels increased 9% between 2013 and 2017, but level PM2.5 particulates fell 19% and  sulphur dioxide is down 36% (see below).

Responding to a question from People Power member Raymond Chan, Environment Secretary Wong Kam-sing said the high ozone level was a result of “the influence of regional pollution.”

Chan said a number of Tung Chung residents had told him they felt local air quality had deteriorated in recent months and feared the opening of the Macau bridge would make the air even worse.

But Wong said apart from ozone, the level of air pollutants in Tung Chung was within government air quality targets.

Source: EPD

But he admitted that no assessment of the air quality impact of the HK-Macau bridge had been made since 2009. The 30-kilometre main bridge is due to open in May.

Wong said a Highways Department study prior to construction had concluded that “air quality at sensitive receivers in the vicinity” of the bridge would comply with government targets.

He said there was no plan to further review Tung Chung air or the effects of traffic crossing the new bridge.

But he said the EPD would continue to monitor the air quality across Hong Kong, including Tung Chung, and was also reviewing the current air quality objectives (AQOs).