Electronic structure and elemental properties of cadmium. (Greg Robson/Creative Commons, Andrei Marincas Shutterstock) According to the data of Dartmouth University, German historical chemist Friedrich Strohmeyer discovered cadmium in 18 17, although German scientists K.S.L.Hermann and J.C.H.Roloff independently discovered cadmium in the same year. In both cases, cadmium exists in zinc oxide, which is usually used as a local medicine. According to the chemicals, KDSP "KDSPE" KDSPS "Stulhmeyer is checking the pharmacy in Germany. He found that several pharmacies in hildesheim used zinc carbonate instead of zinc oxide for external use. He took several samples of zinc carbonate and heated them to convert them into zinc oxide. He noticed that some samples were yellow. The samples were tested for iron or lead pollution, because these are typical culprits leading to color change. No trace of these two elements was found. After further investigation, Strohmeier found traces of unknown elements. He isolated this new metal and suggested replacing the Latin name of calamine (zinc carbonate) with the name of the new element "cadmia".
According to Chemicool, Strohmeyer also found cadmium in many other zinc compounds, including some samples that were considered pure zinc. He estimated that pure zinc and its compounds with cadmium were between 0. 1 and 1%. According to the research of Dartmouth University, when the exploitation and production of cadmium and other metals increased greatly, cadmium was toxic until the industrial revolution in the middle of19th century. Almost at the same time, cadmium was used in some drugs, and many people who took these drugs were eventually poisoned, which is part of the reason why Strohmeier and others were sent to inspect pharmacies in 1945. After the cadmium pollution incident in Japan caused the residents in Toyama Province to get sick and suffer from bone and joint pain, people's research and supervision on cadmium went deeper. It was found that the cadmium content in water used to irrigate nearby zinc crops increased. When crops, especially rice, transmit the increase of cadmium level to people, metals can reduce the calcium content and bone density in bones to a sufficient degree, and in some cases, even simple exercise can lead to fractures.
The source of cadmium is not rich in cadmium. Chlorite is the only mineral containing cadmium. It is most common in a small amount of zinc ore, such as sphalerite.
Cadmium deposits are distributed in Colorado, Illinois, Missouri, Washington and Utah, as well as Bolivia, Guatemala, Hungary and Kazakhstan. However, almost all cadmium used is a by-product of zinc and copper treatment, as well as lead ore. Today, according to the Mineral Education Union, cadmium is usually produced where zinc is extracted rather than mined. Major producers of cadmium include China, Japan, South Korea, Mexico, the United States, the Netherlands, India, Britain, Peru and Germany. "KDSP", "KDSP" and "KDSP" use cadmium "KDSP" in 1927, and the international conference on weights and measures redefines rice according to the wavelength of red cadmium spectrum. This definition was later changed. According to the Mineral Education Alliance,
Cadmium is used in rechargeable nickel-cadmium batteries and can be found in many devices, including mobile phones, cordless power tools, cameras, computers, emergency power supplies and lamps. It is also used in nuclear reactor rods because it absorbs neutrons and maintains the control ability of nuclear fission reaction. According to the data of ATSDR, about 83% of electrolytic cadmium is used for batteries, 8% for pigments, 7% for paints and coatings, 65,438+0% for plastic stabilizers, and 65,438+0% for non-ferrous alloys, photovoltaic devices and other uses.
Who knows? According to Chemicool, the content of cadmium in the earth's crust is one billion 150, and zinc usually has very similar chemical properties. According to the Jefferson Laboratory, the name of cadmium comes from Latin cadmia and Greek kadmeia, which is the ancient name of calamine (zinc carbonate or ZnCO3). According to the International Cadmium Association, cadmium is used as a pigment in red, orange and yellow paints because these colors shine in natural cadmium sulfide. According to the data of International Cadmium Association, Vincent Van Gogh is an outstanding user of cadmium pigments, and he has used various red, orange and yellow pigments produced by him. According to the data of the International Cadmium Association, Germany was the only supplier of cadmium before the First World War. According to the data of US Geological Survey (USGS), cadmium exists in zinc ores, and the ratio of zinc to cadmium ranges from 200: 1 to 400: 1. Cadmium is toxic and can lead to cadmium poisoning. Lenntech believes that health and environmental impact cadmium will lead to a variety of health effects, including stomach pain, severe vomiting, diarrhea, fractures, psychological disorders, cancer, as well as reproductive system, central nervous system, immune system and possible DNA damage.
According to the ATSDR, people and animals are mainly exposed to cadmium through food, water and smoking. Those who are directly exposed to cadmium will also be exposed to cadmium through inhalation.
According to the ATSDR, the cadmium content of green leafy vegetables, potatoes, grains, peanuts, soybeans, sunflower seeds and tobacco leaves is very high, usually 0.05 to 0. 12 mg per kilogram of agricultural products. Generally speaking, non-smokers have an average cadmium content of 0.38 micrograms per liter of blood. In some smokers, it was found that every liter of blood contained 65438 0.58 micrograms of cadmium. Lentek believes that cadmium is mainly concentrated in the kidney and liver, which can stay in the body for many years and slowly leave the body through urine and feces.
Cadmium waste produced by industry is mainly concentrated in soil, and a small amount enters the air through burning fossil fuels, and water enters the air through industrial waste. Cadmium can be absorbed by plants through soil and enter the food supply. Organisms living in soil, such as earthworms, are easily affected by cadmium poisoning, which seriously affects the whole soil ecosystem.
Marine organisms, especially those living in fresh water, include mussels, oysters, shrimps and lobsters, while fish are often prone to cadmium poisoning.
At present, because cadmium is a known carcinogen, many studies are deeply discussing how cadmium affects health. besides