AIR pollution soared to unhealthy levels in some areas last month, the Environmental Protection Department (EPD) reported yesterday.
Low winds and stable weather were the aggravating factors because they trapped the pollutants and prevented them from dispersing, the EPD said.
Readings at Mongkok, where the only street-level air quality monitoring station is found, showed nitrogen dioxide levels exceeded the health safety limit of 150 micrograms per cubic metre over 24 hours.
High levels of the pollutant can cause respiratory problems, including an increased risk of infection.
Raymond Leung Pak-ming of the EPD, who is responsible for monitoring, said the area was troubled by high vehicle emissions and weather conditions made these worse.
Pollution readings at two other EPD monitoring stations did not exceed the health limits, although they were high.
The EPD will soon publish a technical memorandum detailing its air quality standards and how it determines whether factories breach these standards.
