The Tokyo governor Naoki Inose sent message to newly elected Beijing mayor Wang Anshun a few days ago saying Tokyo Metropolitan Government was willing to cooperate with Beijing in the field of air pollution, said Yuta Okazaki, from the Economic Section of the Japanese embassy in Beijing.
Okazaki, who specializes in the environment, was speaking at a meeting chaired by Chinese environmental NGOs Friends of Nature and Nature University Monday.
Speakers at the meeting, which discussed pollution prevention control measures, also included representatives from Greenpeace and other Chinese environmental experts.
"The normal levels of PM2.5 pollution in Japan are around 20 to 30 micrograms per cubic meter, but it's gone up to 60 and 70 in many western areas in recent months," Okazaki said, noting that this was especially the case a few days after January 12, when the Beijing air quality went "beyond index."
Some residents of western Japan were concerned about the pollution and considering to move to the other part of the country, he said.
The National Institute for Environmental Studies (NIES)of Japan conducted the research by analyzing the chemical content of the pollution to discover the source, Okazaki said.
Toshimasa Ohara from NIES said cold winds could blow pollution from China to Japan and South Korea, raising PM2.5 levels, the South China Morning Post reported Friday. Zhang Kai, a campaigner with Greenpeace, said that air pollution is a complex issue, and the source of atmospheric pollution is hard to track.
"Things like the amount of coal burning and the terrain all contribute to the atmospheric pollution in a region [not just air transfer between places]," he said.
Zhang said that PM2.5 particles of 60 to 70 micrograms per cubic meter might have a comparatively high effect on health if it is an average annual figure.
"Otherwise, its impact would be rather low," he said.
Zhang said he sees no necessity for technical cooperation between China and Japan over pollution, since it is the increase in domestic vehicles and coal burning that are the main causes of the pollution.
Yue Xin, an environmental expert from the Chinese Research Academy of Environmental Sciences, said research would be needed to confirm whether pollutants from China have impacted Japan.
"I haven't seen evidence of cooperation of the Chinese and Japanese environmental authorities during the recent period of high pollution," said Yue.