Mitaka City

Beware of Photochemical Smog

Occurs most on days when the temperature is over 20°C and there is little wind

Every year in the Tokyo area, there are photochemical smog alerts from around May through September, and there are more smog alerts in the Tama area than in central Tokyo. Smog alerts and warnings are announced through the disaster prevention radio, the City website, safe security e-mails, bulletin boards at public facilities, etc. Please note that as a rule, smog alerts are cancelled after sunset.

◇ When There Is a Smog Alert or Warning
・ Refrain from stepping outside and from outdoor activities.
・ If your eyes and throat start hurting, wash your eyes and gargle immediately.

・ The status of current photochemical smog alerts can be confirmed via the website of the Bureau of the Environment of the Tokyo Metropolitan Government. (URL:
・ Photochemical smog is reportedly caused by air pollution such as automobile exhaust. To prevent air pollution, it is a good idea to limit the use of cars and ride your bicycle or take public transportation instead, such as a train or bus.

Inquiries: Environmental Policy Section, Ext. 2525


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Mitaka Municipal Office 1-1-1, Nozaki, Mitaka, Tokyo 181-8555, Tel: 0422-45-1151 (Main Switchboard) How to Get Mitaka Municipal Office

Hours: Weekdays, 8:30 a.m. to 5:00 p.m. (Closed: national holidays and during the December 29 through January 3)