The Environmental Protection Department issued health warnings on Wednesday after pollution readings in five districts reached “serious” risk levels.

At 6pm, Tuen Mun, Yuen Long, Tai Po, Tsuen Wan and Kwai Chung in the New Territories recorded a ‘10+’ reading, the highest risk level, Wen Wei Po reported.

Kwun Tong and Mong Kok in Kowloon, as well as Sha Tin in the New Territories, had a reading of ’10’, while other areas across the city – except Grass Island – recorded a ‘9’, which means the health-risk level was ‘very high’.

The department explained that higher than normal levels of nitrogen dioxide and ozone have been recorded in the territory since Wednesday morning, and light wind hindered effective dispersion of air pollutants, according to a statement by the department.

With the Observatory forecasting light winds to continue, pollution levels are expected to remain higher than normal over coming days.

Children, the elderly and people with existing heart or respiratory illnesses are advised to reduce physical activities outdoors.

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