Stay indoors and refrain from airing out rooms when toxic smog from China is in high concentration, the Environment Ministry has advised in provisional guidelines.
In a meeting Monday in Tokyo with about 130 municipalities nationwide, the ministry asked prefectural and major city authorities to increase the number of monitoring posts for PM2.5 — the health-threatening particulate matter found in smog that covered 25 percent of China in January. Kyushu and other parts of western Japan are already being affected.
Particles less than 2.5 microns in diameter, or 2.5 millionths of a meter, can be absorbed into the lungs, leading to heart and lung disease.
With spring winds expected to carry pollution and yellow sand from China, the government will accelerate efforts to analyze the impact on people’s health.
The ministry’s planned provisional guidelines were shown to a separate expert committee that also met Monday. The ministry proposed three options for the planned provisional guidelines, based on which warnings against PM 2.5 will be issued to residents.
The first of the options calls for adopting the present standard, which sets the daily average limit on the amount of small particles at 35 micrograms per cubic meter of air. The second is for setting a different single figure, and the third option calls for introducing multiple figures, depending on which people would be advised to take different steps against PM 2.5.
The ministry plans to compile by the end of this month provisional guidelines for alerting the public in the event of high concentrations of toxic smog.
Meanwhile, the ministry will also check the effectiveness of face masks and electronic air cleaners.
At the meeting of the municipalities, the ministry also explained measures listed under the emergency action program it announced Feb. 8, including a plan to create guidelines for municipalities to issue alerts in case of high concentrations of toxic smog.
The ministry set a target of increasing the number of monitoring posts for PM2.5 to some 1,300 by the end of March but has yet to reach half the figure due to municipal fiscal shortfalls, among other reasons.
China’s national standard for PM2.5 is 75 micrograms per cubic meter daily and the government is aiming to establish an average of 35 micrograms annually.
Beijing far exceeds these levels, but efforts are under way to reduce annual PM2.5 concentrations to 60 micrograms per cubic meter by 2015 and 50 micrograms by 2020 in order to meet the national standard by 2030.
On Jan. 12, Beijing recorded PM2.5 levels of more than 900 micrograms per cubic meter.
The particles are generated by burning fossil fuels, wood and using pesticides and contain various elements, including nitrates, sulfates, organic chemicals as well as pollen fragments.
It is believed that explsure to PM particles has a significant association to premature death from heart or lung disease. They can also increase the risk of heart attacks, asthma attacks and bronchitis.