Observe life, talk about the air pollution you feel, and express your own opinions

Feeling air pollution: factory emissions, car exhaust, farmland burning, forest fires, cooking smoke (including roadside barbecues), dust (including construction sites), etc.

Viewpoint: 1. Overview of air pollution

Even when the sky is clear, the atmosphere around us is not as clear as it appears on the surface. The air is filled with invisible solid, liquid and gas substances in different forms: such as pollen, bacteria, smoke, moisture, etc. The so-called air pollution means that the air contains one or more pollutants, the amount, nature and duration of which will harm human, plant and animal life, damage property, or interfere with a comfortable living environment, such as odorous exist. In other words, as long as the amount, nature and time of a certain substance's existence are enough to have an impact on humans or other living things and property, we can call it an air pollutant; and the phenomenon caused by its existence is air pollution. Before we can understand what substances put into the air cause pollution, we need to understand what clean air is made of. The composition of clean air is shown in Table 1: What we usually call "air pollutants" are nitrogen dioxide and ozone. Substances such as sulfur dioxide and carbon monoxide are present in very small amounts in clean air; however, when polluted, certain types of these specific substances increase in large amounts. In other words, abnormal increases in certain substances in the air produce air pollution.