28 prefectures issued photochemical oxidant smog warnings in 2007
A record number of 28 of Japan's 47 prefectures issued photochemical oxidant smog warnings in 2007, including Niigata and Oita prefectures, which issued warnings for the first time, the Environment Ministry said in a report Tuesday. The number of people who reported health problems due to the smog, which causes symptoms such as eye and throat pain, reached 1,910 in 14 prefectures, the ministry said. Warnings were issued in Saitama on 32 days, the highest number, followed by Kanagawa on 20 days, and Chiba and Tokyo on 17 days.