Japan, South Korea concerned that China's smog will affect them
South Korea and Japan are concerned that winds will carry smog cloud eastwards; both willing to help bring down pollution levels
Julian Ryall in Tokyo and Audrey Yoo
South Korea and Japan have sounded the alarm about potentially hazardous air pollution from northern China, which is expected to worsen this winter.
In South Korea, local media have called recent smog an "air raid", while in Japan, residents of Chiba prefecture have been told to stay inside as toxic fine-particle pollution blanketed parts of the region to the east of Tokyo.
The concern now is that the autumn westerly winds will once again bring elevated levels of particulate matter and pollution to Japanese and South Korean cities. And that will get worse when Chinese power plants start burning massive amounts of coal for heating during the winter months.
In recent weeks, parts of northern China, particularly Harbin , have all but ground to a halt because of smog containing contaminant levels up to 50 times that deemed safe by the World Health Organisation.
Japanese media have also reported that Japanese working in major cities in China are so concerned about the impact of air pollution that they are sending their families back to Japan.
The Japanese embassy in Beijing held a meeting for Japanese residents on October 28, with a doctor telling those present, "The options are to go on vacation, change your residence or find a new job somewhere free from the pollution," the Mainichi newspaper reported.
Watch: Beijing's smog from atop the Forbidden City
The alert in Japan was the first since the national government in March ordered local authorities to issue warnings to residents about dangerous levels of pollution.
On Monday the average hourly density of PM2.5 before 7am stood at 127 micrograms per cubic metre in the city of Ichihara, beyond the official daily limit of 70mcg. PM2.5 particles are 2.5 microns or less in diameter and lodge deep in the lungs.
The new levels were introduced after smog enveloped Fukuoka, Nagasaki and of other cities in western Japan in spring.
Television coverage has shown pictures of hazy skies over the capital and pedestrians wearing masks over their faces and mouths.
"It seems to have been okay here so far, but I have been watching the news and it is worrying," said Kanako Hosomura, a housewife from Yokohama, south of Tokyo. "I bought face masks back in the spring because of what was happening then and I'll buy some more now just to be safe.
"But I hope we do not have a problem here because the children do not want to be indoors all day long, but they cannot go to the park when it is very bad."
In South Korea, mask sales from one of the country's biggest online retailers, Gmarket, jumped 481 per cent from October 24-30, compared to the same period last year.
South Korea's environment ministry said that to cope with the smog, Seoul plans to cooperate with China on environmental technology.
The Chinese government has invited a team of Japanese experts to visit in an effort to identify ways of reducing the problem at its source, with the usually stridently nationalistic Yomiuri newspaper even suggesting that the problem might be a way for the two sides to bury the hatchet over other issues.
"Environmental protection is an important task that Japan and China must carry out together, despite their feud over the Senkaku Islands," the paper said in an editorial, adding that exchanges of experts, "apparently indicates a sense of urgency shared by both countries about air pollution in China.
"We believe that Japan's environmental know-how - the technological solutions to its own past air pollution problems - will do much to improve the situation in China."
Additional reporting by Reuters