SHANGHAI- Average levels of hazardous floating particle pollution in 338 Chinese cities dropped by 5.3 percent in October from a year earlier, the environment ministry said on Friday, as it prepares for another winter campaign against polluters.

The Ministry of Ecology and Environment data showed that PM2.5 - lung-damaging particulates of less than 2.5 microns in diameter - fell to an average of 36 micrograms per cubic metre over the month, nearly reaching the state standard of 35 micrograms.

The average per cubic metre over the first 10 months of the year stood at 37 micrograms, down 7.5 percent from the same period of 2017. China's biggest smog build-ups usually occur between November and March, when predominantly coal-fired winter heating systems are turned on throughout its northern regions.

The most polluted city in October was Anyang in central China's Henan province, the ministry said. Over the first 10 months as a whole, the major coal-producing city of Linfen, Shanxi province, was the most polluted, followed by Tangshan in Hebei province, China's biggest coal-producing city.

Special anti-pollution measures are starting to kick in throughout northern China, with cities under pressure to cut industrial production by as much as 50 percent to meet air quality targets over the winter.

(Reporting by David Stanway; Editing by Tom Hogue) ((david.stanway@thomsonreuters.com; +86 21 6104 1799; Reuters Messaging: david.stanway.thomsonreuters.com@reuters.net))