What are the effects of drying clothes in foggy weather?

Fog is composed of water molecules evaporated from the ground surface condensed by the influence of cold air and fine water droplets (fog droplets) suspended in the air. The radius of these tiny droplets is only 0.001 mm to 0.05 mm. It is difficult to see a single droplet clearly with the naked eye. Only the hundreds of millions of droplets gathered together can form a fog that can be seen clearly by people. If the visibility is less than 10,000 meters, it is light fog, and if the visibility is less than 1,000 meters, it is heavy fog; if the condition of the sky above the head can be distinguished, the fog is discernible fog, and if the condition of the sky above the head cannot be discerned, the fog is indiscernible fog. From late autumn to early winter, the temperature gradually drops, and the climatic conditions are more suitable for the generation of fog, so this is the season where fog occurs frequently. The fog formation time is generally from early morning to 8 o'clock in the morning, but the earliest appearance time of autumn fog can be from 21:30 to 22:00 in the first half of the night. The fog is most dense in the morning and takes different lengths of time to dissipate. Affected by terrain, some areas have thick fog and long foggy days.

Since fog droplets are formed by the cooling and saturation of invisible water vapor in the air, the size of the fog is related to the amount of water vapor in the air. The greater the air humidity, the more condensation nuclei (smoke particles, dust, etc.), the stronger the cooling effect, the more condensed fog droplets, and the fog is likely to become larger and thicker. Because the air in cities is extremely rich in dust, there are many buildings near the ground, and the wind speed is lower than in suburbs, fog is more likely to form in cities than in rural areas. The modern urban atmosphere is polluted to varying degrees. The tiny water droplets in the fog dissolve and adsorb some pathogenic microorganisms and other harmful substances on the surface. The most important sources are from two aspects: First, harmful industrial dust and exhaust gas. Fog days mostly belong to denatured cold high-pressure weather systems, with low wind speeds and often accompanied by strong temperature inversions, which are not conducive to the diffusion of pollutants in the atmosphere. The extremely small fog droplets cause acids, alkalis, phenols, and Pathogenic substances harmful to the human body, such as amines, benzene, salts, and heavy metal particles, accumulate and spread everywhere, unable to diffuse or dilute. Moreover, various harmful substances tend to react more frequently with each other, and the new toxic substances generated are more toxic than the original ones. Some pollutants are more harmful to the body. Therefore, fog intensifies air pollution, accelerates the diffusion and spread of various pathogenic sources, intensifies the invasion of diseases into the human body, and induces various diseases such as lungs, trachea, bronchus, throat, nostrils, eyes, skin, etc., as well as cancer, An important factor that causes mutagenesis or promotes cancer. The second is that the hydrocarbons, nitric oxide and nitrogen dioxide in the atmosphere emitted by cars react chemically under the action of sunlight to produce light blue composed of ozone, nitrogen oxides, formaldehyde, acetaldehyde, phenol and other oxidants and heavy metals. Photochemical smog will not only aggravate the haze, but also irritate people's eyes and mucous membranes, causing headaches, vomiting, and breathing disorders. It can easily induce chronic respiratory diseases, cause abnormal lung function in children, and even cause death in severe cases.

Because of this, among various disease-causing meteorological factors, fog poses the greatest threat to human health, and the months with the most foggy days are also responsible for bronchitis, laryngitis, pneumonia, rhinitis, conjunctivitis and In seasons where allergic diseases are common, the excess mortality rate among patients with pneumonia, lung cancer, etc. is as high as over 40%. As for the hidden harm caused to the body by inhaling certain harmful substances, it is even more immeasurable.

In order to prevent fog from harming health, people living in cities should take active protective measures during foggy seasons to minimize the harm of fog to health. In particular, patients with respiratory and cardiovascular diseases, as well as people with allergies, people with weak constitutions, the elderly and children, should pay more attention to reduce activities in foggy environments and avoid being in foggy environments as much as possible. Exercising or working in an environment for too long.