二氧化硫、氮氧化物以及可吸入颗粒物这三项是雾霾主要组成，前两者为气态污染物，最后一项颗粒物才是加重雾霾天气污染的罪魁祸首。它们与雾气结合在一起，让天空瞬间变得灰蒙蒙的。颗粒物的英文缩写为PM，北京监测的是PM2.5，也就是空气动力学当量直径小于等于2.5微米的污染物颗粒。这种颗粒本身既是一种污染物，又是重金属、多环芳烃等有毒物质的载体。

Sulfur dioxide, nitrogen oxides and other breathable particulates are the main components of "haze." The first two are gaseous pollutants, and the last one is the main culprit of haze weather pollution. They are combined with fog, making the sky instantly gray. Particulate matter is abbreviated as PM. Beijing monitors PM 2.5, a pollutant particle whose aerodynamics equivalent diameter is less than 2.5 microns. This particle is not only a pollutant, but also a carrier of heavy metals, polycyclic aromatic hydrocarbons, and other toxic substances.

今天，我园开展了“正确预防雾霾，健康从我做起”的安全课堂。

Today, SCL launched the "correct prevention of haze, health from me" safety classroom.

老师们向孩子们详细介绍了雾霾形成的原因，雾霾天气可能引发的疾病，以及如何采取措施避免雾霾对人体的伤害。

The teachers gave the children a detailed account of the causes of haze formation, possible diseases caused by haze, and how to take measures to avoid these negative health effects.

通过学习，我们知道了：在雾霾天气要尽量减少外出，有效预防雾霾对健康的影响；要做好户外活动防护措施，佩戴专业口罩，减少户外有氧锻炼；在室内要关闭门窗，并注意饮食，多食清淡食物多饮水。

 When the Air Quality Index number is high, we know to minimize time spent outdoors, wear professional masks, and reduce outdoor aerobic exercise. When indoors, we know to close the doors and windows, and to eat lightly as well as increasing water intake.