Can copper pipe produce verdigris when used for a long time? Is it harmful to human body?

In 1754, ELLER published an ancient paper on the judgment of the non-toxicity of copper. Subsequently, ARW AND GAUTIER also published a research paper on the statement that copper is toxic in 1883. In many other literature we can also see a large number of negative reactions to the toxicity of copper.

At present, there are articles citing the explanation in Cihai to prove that verdant is toxic, apparently this statement is too simple and one-sided, and the version of Cihai has been too old, not revised for many years. In fact, the 1988 edition of The Encyclopaedia of Japan, published in Japan, has a very detailed definition: "[7] Basic copper carbonate CuCO 3.Cu(OH) 2(patinosa), a beautiful green protective film formed on the surface of copper by prolonged exposure in outdoor environments to sulfur compounds contained in the urban atmosphere. The main composition is basic copper carbonate, copper and sulfur compound reaction generated copper sulfide continue to oxidize the formation of material. There is not enough sulfur in the atmosphere to prevent oxidation and a dark red protective film forms on the surface of the copper. In coastal areas the patina contains basic copper carbonate and is used as a colouring for eaves because of its beautiful hue. It had been mistaken for toxic, but no toxicity was found after sanitation.

In 1962, a laboratory of Tokyo University Medical College began to conduct a 3-year study on "copper and hygiene", and came to the conclusion that copper was non-toxic through animal experiments (acute toxicity, chronic toxicity). They said, "Because verdigris is insoluble in hot and cold water, it is not absorbed into the body. Even if excessive verdigris into the stomach, it will cause vomiting because of the stimulation of the gastric mucosa caused by verdigris, which is eliminated before being absorbed by the human body. In animal experiments, the experimental method is difficult to check because it is insoluble in water, so we had to break the verdigris into fine powder and particles, and then make it suspended in 2% Arabic rubber, and put it into the body with a probe from the mouth to determine its lethal amount to test.

Copper water pipe as the first choice of five-star hotel water supply pipe, has become the world standard, and because in the building, the whole water supply system is a closed system, the inner wall of the copper tube is not directly in contact with the atmosphere, so the inner wall of the copper tube is not the formation of verdant. At present, the world's five-star hotels almost 100% is the use of copper water pipes, China is no exception, China's zhongnanhai buildings and some key cultural relics protection of modern buildings, very early has chosen copper pipes as water supply pipes, the guests or owners who live in the building has never occurred the event of verdana poisoning.