SHENZHEN will have more smoggy days ahead because of unfavorable weather conditions, according to environmental officials.

    The average PM2.5 concentration was 48 micrograms per cubic meter this month, nearly double the level in September, according to the latest report released by the city’s environmental commission.

    The Air Quality Index, a measurement of air pollution that the city adopted last year, reached “good” and “fairly good” levels on 90 days in the third quarter, according to the report.

    The average PM2.5 level was 29 micrograms per cubic meter in the first nine months of the year, the fourth-lowest among 74 major cities in China.

    But the city’s air quality will become worse in the next two months because Shenzhen usually has less precipitation and more winds from the north in fall and winter.

    Environmental experts said winds from the north bring pollutants from neighboring cities and less precipitation prevents them from being dispersed.

    In addition, strong sunlight makes it easier for pollutants to undergo photochemical reactions and produce PM2.5 particles and ozone, causing hazy days, experts said.

    The city will continue its efforts to reduce air pollution, which include eliminating vehicles that pollute heavily and controlling pollution from ships docked at ports and from heavy machinery.

    (Zhang Yang)