An acidifying substance containing ozone, which is produced by photochemical reaction of nitrogen oxide (NOx) or volatile organic compound (VOC) as ultraviolet ray of the sun, is called "photochemical oxidant", and the concentration of the photochemical oxidant is The higher it is called "photochemical smog". Due to photochemical smog, health damage such as eye irritation and sore throat occurs.
出典：環境省ホームページ「各都道府県における注意報等発令延日数及び発令都道府県数の推移」(http://www.env.go.jp/air/osen/oxidant/days_adv.pdf)より表を加工し、利用しました。 なお、英訳は当サイト側が行ったものです。
Source: Ministry of the Environment home page "of warning, etc. issued
total number of days and the number of issued prefectures in each prefecture
transition" and from Table (http://www.env.go.jp/air/osen/oxidant/days_adv.pdf)
We processed and used it.English translation was done by this site.
As you can see from the graph, the number of days differs depending on
the year, but when you look at the approximate curve, you can see that
the number of days of issuance has increased slightly.
When the photochemical smog warning is issued, it is desirable to take
measures such as avoiding outdoor exercise, refraining from going out, closing the window of the house.
