Why does heavy fog affect traffic?

The foggy weather has a great influence on traffic. In foggy weather, planes cannot take off and land, and cars and ships are prone to traffic accidents due to poor visibility. Fog reading agricultural production also has certain harm. If it is foggy for several days, it will make crops lack light, affect growth and induce diseases. If wheat meets fog for more than 3 days at heading, it is easy to cause scab. Fog is also harmful to human health. According to the measurement, the proportion of substances harmful to human body, such as acid, alkali, salt, amine, phenol, dust, pathogenic microorganisms and so on. The content contained in fog drops is dozens of times higher than that of ordinary atmospheric water drops. If people move in the fog, they will inhale these harmful substances in the fog, which will induce or aggravate many diseases such as tracheitis, pharyngitis and conjunctivitis.