TIANJIN — North China’s Tianjin municipality saw its PM2.5 concentration drop 31 percent year on year in October and November following a spate of antipollution efforts, local authorities said on Dec 6.

The average reading of PM2.5, airborne particles smaller than 2.5 microns in diameter that are more damaging to health, was 58 mg per cubic meter during the two months, the Tianjin Environmental Protection Bureau announced.

The concentration in November in particular fell 49 percent year on year, said Deng Xiaowen, head of Tianjin’s environment monitoring center.

The improvement was a result of a series of well-targeted measures, according to Yang Yong from the Tianjin Environmental Protection Bureau.

Authorities in Tianjin, which borders Beijing, have shut down 9,081 highly polluting plants and ordered another 9,873 to improve pollutant treatment capacity this year.

The city also plans to ban indiscriminate coal burning by the end of 2018 with 1.21 million households switching from coal-fired to gas and electric heating sources.

Authorities in Tianjin and neighboring Hebei province, home to several of China’s most polluted cities, previously ordered heavily polluting industries, including steel, casting and coking, to restrict production and cut emissions during the winter heating period.

The Beijing-Tianjin-Hebei region sits in the heart of the North China Plain where air pollution, particularly winter smog, often occurs as a result of the high concentration of industrial and vehicle emissions, limited air circulation and the burning of coal.

More residents are increasingly worried about the health impacts, particularly of PM2.5. The smaller particles pose a greater health risk as they can get deeper into the lungs than larger particles.

China has set a target to reduce the average PM2.5 level by at least 15 percent in the cities around the Beijing-Tianjin-Hebei region between October 2017 and March 2018, compared to last year’s level.