• Tue
  • Dec 23, 2014
  • Updated: 2:20am
NewsHong Kong

Worst smog of the year prompts Hong Kong government health warning

Low pressure system sends pollution levels rocketing across the city on the worst day of the year so far for air quality

PUBLISHED : Monday, 09 June, 2014, 3:03am
UPDATED : Sunday, 15 June, 2014, 3:11pm

Hong Kong choked on its smoggiest day of the year so far yesterday as a trough of low pressure left the city coping with pollution that represented a "serious risk" to health.

At 7pm and 8pm, all 12 of the city's general pollution monitoring stations and all three roadside stations recorded pollution levels posing a "very high" or "serious" risk to health. All but two general stations and all of the roadside stations were at level 10+, the highest level on the government's Air Quality Health Index (AQHI), introduced last year.

At 2pm, the Tung Chung general station recorded 24-hour concentration levels of PM2.5 - fine suspended particles small enough to lodge deeply into the lungs - at 128 micrograms per cubic metre, more than five times the maximum safe level set the by World Health Organisation. Ozone concentration hit 269, against a WHO maximum eight-hour mean level of 100.

Watch: How to deal with Hong Kong's smog

Ozone concentration was even higher elsewhere, hitting levels of more than 300 in areas including Central and Western, Tsuen Wan and Yuen Long, which all recorded 10+ AQHI readings.

An AQHI level of 10+ triggers a warning from the Environmental Protection Department for people with heart disease or respiratory illnesses to avoid outdoor activity, especially in areas with heavy traffic.

A department spokesman said the city was experiencing higher regional ozone pollution and that health risks were now high. Weak winds were not able to disperse pollutants, the spokesman added.

The deteriorating air quality came as a trough of low pressure affected southern China.

Professor Wang Tao, chair professor of atmospheric environment at Polytechnic University, said high levels of air pollution were typical during low-pressure systems.

"Weak horizontal winds and descending air create 'stable conditions', rendering pollutants in the city and nearby unable to move," he said. "People tend to pay more attention to PM, while the dangers of ozone pollution, which is actually getting worse, tend to go unnoticed."

Ozone is not emitted but produced through chemical reactions between nitrogen oxides from power plants and car emissions, and volatile organic compounds.

Most of Hong Kong's ozone pollution is a mix of background pollution from external and local sources. Long-term exposure to ozone is linked to asthma, bronchitis, heart attacks and even death.

Clean Air Network chief executive Kwong Sum-yin said days with multiple 10+ recordings occurred in January during a northeast monsoon, but yesterday would have marked the most polluted day so far this year.

The Observatory forecasts showers and squally thunderstorms today. Shortly after midnight this morning, the Environmental Protection Department's website was predicting "moderate to very high" health risks from pollution this morning, with a "low to moderate" risk in the afternoon.

Watch: The dangers of air pollution - videographic



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This article is now closed to comments

And still the ships in HK waters are belching out black smoke !
On Saturday morning, I watched a large container ship depart Kwai Chung belching black and grey filth that gradually spread out over Tsuen Wan and Kwai Chung. It hung there long after the ship had departed. When are we going to see some action to stop this industry choking us!
I was born in HK... have lived here my whole life.... have 3 small kids. I love this place but days like yesterday really make me wonder if we should be packing up and moving on. the simple fact is that simply living in hong kong will shorten their lives. heartbreaking.
While our politicians argue about occupying this and that, when will they spend their time on we the people? We the people want clean air, clean ocean and clean water. When will the politicians spend time talking about the environment, clean energy like solar and wind, clean transport like electric buses and cars. What's more important to our politicians? Our lives or their glory?
Not only "people with heart disease or respiratory illnesses" are affected by bad air quality, but also elderly and children. Considering the severe impact on our health, AQHI of high and above (red, brown and black) should have the same public attentation as for example typhoon signals. High AQHIs should be shown on TV screen. And a severe AQHI (10+) should have the same measures as typhoon signal 8.
Hong Kong being such a small speck land mass shouldn’t continue producing electricity by burning fossil fuel. The viable alternative is importing electricity from Guangdong. Not it is a novelty since China Light is already building nuclear plants and importing electricity from across the boarder. Hong Kong Electric still stands firm with added resolve by persuading its customers and stockholders with negative views about importing electricity.
Hong Kong Electric may be the largest single source of air pollution for Hong Kong. It is meaningless to boost our electric rail transit as our major transport and pushing for electric cars running in our city while the electricity they consume comes from a polluting source.
Hong Kong Electric should refrain from self-interest only.
All worried about decline in retail sales, mtr, and arts
But when it comes to air and education, such a deafening silence - how shameful.
When we consume less, then there will be fewer containers shipping goods to us, and fewer ships and less dirty diesel burnt. We the people are testing the limit of our planet and is challenging the earth's limit everyday. Sooner or later, the earth will be so polluted that we will all die from starvation or diseases.
Dont forget those ugly and polluting container ships.
Survival of the richest....but perhaps not with poisonous air.
This is a great comment, except everyone is affected by the pollution not just kids and the elderly. I had a migraine yesterday for the first time in ages because I had to travel into Mongkok with all this c**p in the air.
There needs to be a movement amongst residents whereby if a reading is high in the morning they should ring in sick. The government are in the pocket of big business and what does big business need to keep running... human capital. Maybe the idiots running this place would actually do something if their pals started losing money.



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