Air pollution levels remained high yesterday, with concentrations at all 11 general monitoring stations exceeding World Health Organisation guidelines, Greenpeace said.
Readings at the three roadside stations - in Causeway Bay, Central and Mong Kok - were 'very high' throughout the day, with the air pollution index hitting a high of 135 in Causeway Bay at 11am.
Among the 11 general stations, Kwai Chung fared worst at 93.
An air pollution index of over 100 indicates the pollutants pose immediate health risks, especially to people with respiratory or heart illnesses.
Between 3pm and 4pm, Greenpeace said all 11 general stations had either one or two pollutants above WHO guidelines. The three roadside stations, known for marking very high levels of pollution, also exceeded the guidelines. Respirable suspended particles and sulfur dioxide were the key pollutants.
At the same time, the Observatory recorded low wind speeds. This showed that the air pollution was produced locally, Greenpeace campaigner Prentice Woo Wai-muk said, adding that the government should no longer blame mainland sources.
