Hong Kong atmosphere is cleaner during the demonstration days

The wave of protests in Hong Kong over the past few days has caused no trouble for travel, but the blockade of many roads in crowded areas has made the sky more clear.

According to Hong Kong Environmental Protection Agency (EPD) data, air quality in Causeway Bay, Mong Kok and Central District is higher than normal days. The risk of health effects due to environmental pollution in all three areas is lower than normal. Except for Mong Kok district, the low level continued to maintain yesterday.

Pedestrians enjoy the fresh air while reading Connaught Street in Hong Kong Central District.(Photo: Felix Wong / SCMP)

Nitrogen dioxide is an air pollutant that is released from vehicles. In Causeway Bay, nitrogen dioxide levels have decreased from 125 micrograms / m3 (at 10 pm on September 28) to 60 micrograms / m3 (after 9 am). Meanwhile in Mong Kok, the concentration dropped from 126 micrograms / m ³ to 70 micrograms / m3 for more than a night. In the Central District, the level of pollution decreased after protesters began to occupy the Harcour Road.

Kwong Sum-yin, executive director of the Clean Air Network, said the protests made congested road traffic inadvertently improved air quality in many areas. EPD spokesman confirmed that traffic volume decreased in many areas while reducing air pollution levels.

According to Kwong, this temporary improvement shows that government regulation for low-emissions areas will be effective. Accordingly, polluting vehicles will be prohibited from moving in crowded streets. Bus companies have been encouraged to use more "green" means to reduce pollution, but are not effective.