Breathe easier, Hong Kong is on course to hit global air pollution target
Cleaner shipping fuel and a campaign to phase out dirty old vehicles are two of the reasons for the improvement, but more still needs to be done
A report on Hong Kong’s efforts to improve air quality is expected to show “significant progress” towards hitting international targets in cutting pollutants over the past 4½ years and by 2020, the city’s No 2 environment official says.
Annual average concentrations of PM10 – specks of respirable particulates smaller than 10 microns that can enter deep into the lungs – dropped from around 53 micrograms per cubic metre in roadside readings in 2012 to under 40mcg last year.
Roadside levels of nitrogen dioxide (NO2) fell from 120mcg to 80mcg.
The report assessing the Clean Air Plan, laid out in 2013, projects a drop in PM10 to around 30mcg by 2020, the third of three interim targets for the pollutant set by the World Health Organisation, but still a notch above the ultimate level of 20mcg.
NO2 is forecast to drop to about 65mcg. The WHO’s only standard for NO2 is 40mcg. Projections for other pollutants such as PM2.5 will be known when the report is published in a few weeks.
“There has been a significant impact on the air quality of Hong Kong in terms of [bad air] days and reduction of pollutants,” environment undersecretary Christine Loh Kung-wai told the Post. “The things we have set out to do, we have done them all.”
She said most progress was made in shipping emissions, not least because sulphur dioxide (SO2) emissions fell from 16,480 tonnes in 2012 to 11,460 last year – largely due to legislation in 2015 requiring ships to switch to a cleaner fuel at berth – but also because the city had influenced mainland China to follow suit.
“The result had exceeded what we expected,” she said.
A new emissions control area for Pearl River Delta waters is expected to be set up by the mainland in 2019, requiring all ships in regional waters to burn low-sulphur fuel, not just at berth.
That measure is expected to lower local levels of SO2 to 5,120 tonnes by 2020.
Hong Kong will have to amendment its legislation on the fuel switch before 2019 to dovetail with mainland law.
Despite the improvements, most pollutant levels are still far above the WHO’s ultimate air quality targets. Roadside and ambient pollution hover at unsafe levels and smog-inducing ozone remains a major headache in the region.
Just last week, air quality monitoring stations in the city hit “very high” or “serious” health-risk levels for the third time this month as a result of higher regional pollution.
Environmental groups concede that some policies such as a HK$11.7 billion plan to phase out old polluting commercial vehicles that run on diesel have helped to improve roadside air, but there would be diminishing returns as vehicles aged.
Dr Cheng Luk-ki, head of scientific research at Green Power, said many long-term polices such as curbing the growth in cars remained unfilled and was making traffic congestion and pollution worse.
Patrick Fung Kin-wai, chief executive of the Clean Air Network, said: “There has been insufficient coordination between policy bureaus on this.”
Loh admitted more work was needed and acknowledged that most pollutant levels were still far above the WHO’s ultimate targets, which were cited in the 2013 plan as one for “constant reference”. “We know it’s not enough.”
While ozone pollution fell slightly last year, it has rebounded to levels seen 20 years ago.
Loh said the hazardous secondary pollutant – formed by reactions of primary pollutants under the sun and the cause of most of Hong Kong’s high pollution days – was more challenging to control and required further scientific research and cooperation between the Hong Kong and Guangdong governments.
She added that there was a limit to what Hong Kong could do in this respect.
“The ability for Guangdong [to reduce primary pollutants] is much greater than ours,” she said.
The Hong Kong government is currently conducting a five-year review of the city’s air quality objectives, which are benchmarked against a selection of WHO guidelines.
The guidelines feature three interim targets and one ultimate target, which serve as a reference for governments to conduct air quality management and policymaking.