Air purifiers are on show at a school facilities fair in Beijing. (File photo: China Daily)

The National Health Commission issued a guideline on Tuesday suggesting kindergartens, primary and middle schools be equipped with air purifiers to reduce concentration of PM2.5, Beijing Daily reported.

Kindergartens, primary and secondary schools, as well as fitness clubs, were also advised to install fresh air ventilators so the concentration of CO2 wouldn’t be too high. Schools should suspend outdoor activities and avoid strenuous exercise indoors, the guideline suggested.

Three citizen groups, including elders, children and pregnant women, patients with chronic diseases as well as long-term outdoor workers are regarded as particularly vulnerable to air pollution, according to the guideline.

The guideline indicated individuals, especially vulnerable groups, should learn to use protective tools to reduce health risk under exposure to smog.

The elderly, children, pregnant women and those suffering from heart and lung disease are advised to stay indoors in moderately or heavily smoggy weather, the guideline read.

Vulnerable person who have to go out should wear respirators after consulting doctors, in order to prevent the inhalation of smog. They are also suggested to change clothes and wash their face, nasal cavity and skin exposed to the air after coming back indoors.

In smoggy weather, horizontal visibility is reduced to within 10.0 kilometers and the sky turns muddy and turbid, which may cause discomfort to the eyes, throat and skin. It may also do harm to mental health, leading to negative feelings or even depression, the report said.