You know why the collars and cuffs of shirts are polluted more than other places on our clothes. Of course the reason is, that these places are constantly rubbing about our body in the process of wearing. They are in tight contact with the skin of the hands and neck. But this is not the main reason. Is there no other place where the same thing happens, for example, on the shoulders or under the belt, in the place where the shirt is tucked into trousers. We wash ourselves and the purity of the body is the same everywhere.
The pollution of the cuffs and collars is affected by the environment. A lot of dust flies in the air. This dust and flies under the collars and cuffs, and then already rubbed under the sock. Watch how your shirt gets soiled if you spend the whole day indoors or you move around the city. Of course, in the office, the shirt will keep its freshness longer than in the open air. And absolutely, it does not depend on the purity of your body, although there are exceptions. By the cuffs of his shirt, we can determine the air we breathe. And it's not at all difficult to guess that he is not so clean. Although this air is not perfect, but also not dangerous.

By the way, excellent was a show about white collars ... image source