Beijing's neighbors major source of PM 2.5

Neighboring regions are one of the major contributors to the Chinese capital's PM 2.5 pollution - particulate matter with a diameter less than 2.5 micrograms that can go deep into the lungs and is extremely harmful to health - according to recently updated research by the city's environmental watchdog.

As much as 28 percent to 36 percent of Beijing's PM 2.5 pollution is contributed by neighboring regions, including Tianjin and Hebei province, according to the PM 2.5 source-identification study released by the Beijing Environmental Protection Bureau during a news briefing on Wednesday.

The study was jointly conducted by the bureau, the Beijing Environmental Protection Monitoring Center, the Chinese Research Academy of Environmental Sciences and Peking University, the bureau said.