Why do some people's hair turn green in some houses in Anderslov, a small Swedish town?

The main reason is that the hot water pipes and hot water reservoirs in the new house contain copper. When hot water accumulates in the reservoir for a long time, a small amount of copper will enter the water body and stay on the hair after bathing, making the hair slightly green. As long as you wash your hair with cold water in the shower, you can avoid "dyeing". This phenomenon is very common in new houses. With the use of hot water pipes, it will gradually decrease until it disappears, which is harmless to the body. The above explanation was published in a newspaper in southern Sweden.