Air-pollution levels at all three of Hong Kong's roadside stations hit "very high" readings yesterday, prompting calls for Chief Executive Leung Chun-ying to deliver bold initiatives to reduce smog in his policy address on Wednesday.
At 4pm yesterday, the Environmental Protection Department's roadside station in Causeway Bay recorded an air pollution index of 153. The reading was 119 in Central and 111 in Mong Kok.
A reading of between 101 and 200 means the pollution level is very high and that people with respiratory illnesses may notice a mild aggravation of their condition, according to the department's air pollution index.
The 11 general stations also recorded "high" pollution levels at 4pm, ranging from 67 in Tap Mun to 91 in Kwun Tong.
"We are now affected by a dry continental air stream with high regional background pollution. The wind is light," a department spokesman said yesterday.
"The very high roadside air pollution index is caused by the trapping of air pollutants emitted by motor vehicles, coupled with high regional pollution."
The president of the environmental group Green Sense, Roy Tam Hoi-pong, called for bold initiatives in the policy address. He said the main reason vehicles emitted so many pollutants was that they were not properly maintained.
"The government requires vehicles to be examined once a year at present. I think vehicles should be examined every six months," he said.
He also said the government should discuss ways to tackle air pollution with the Guangdong government, as winds often blow pollutants generated by factories across the border.
Melonie Chau Yuet-cheung of Friends of the Earth said the government must deal with the phasing-out of diesel-fuelled cars in the policy address.
She said that "80 per cent of all roadside pollutants were caused by these old vehicles" still running on the city's roads.
But she said recent warmer temperatures were a factor in the raised figures.
Chau also said wider co-operation would be needed between the local and Guangdong authorities in the long run.