CÁDMIO um metal muito TÓXICO e muito USADO. Por que o CÁDMIO é TÓXICO? O que é CÁDMIO?

This metal is one of the most toxic in the world and also one of the most used, Cadmium hey Engineering lovers, most people are aware of the dangers of lead or mercury in their homes and even in the water supply. We have tests to detect lead in our bodies and even filters to remove some heavy metals from drinking water. But perhaps while you are eating a piece of carrot directly picked from the ground, there is perhaps a hidden danger, or rather, a dangerous metal that you should be careful about ingesting, cadmium.

Well, cadmium is a natural metal, like silver or platinum that is found in nature, usually in zinc ores. It is a chemical element with symbol Cd and atomic number 48 and is chemically similar to the other two stable metals in Group 12 of the periodic table, zinc and mercury. It is soft, silvery white in color with a bluish tinge that diminishes when exposed to air or moisture.

It is considered a rare metal, ductile and malleable, which means you can shape it easily and is resistant to corrosion and has a lower melting point than most other transition metals. It is found in small quantities in ores such as sphalerite, which is a zinc ore, and greenockite. One of the important properties of cadmium is its ability to absorb neutrons, which makes it useful in nuclear applications, such as in nuclear reactors and radiation control materials.

Because cadmium has a low melting point of 321 degrees Celsius and is resistant to corrosion, it is a popular choice for coating steel for industrial purposes and is also an efficient conductor of electricity. It is also used to stabilize paint pigments ranging from yellow to brown, steel coating, batteries, solar energy, and barrier material in nuclear fission reactors. But okay, let's start from the beginning, when was cadmium discovered?

It was discovered in 1817 by German chemist Friedrich Stromeyer. He was working with samples of sphalerite, which is a zinc ore, when he noticed the presence of a new metal. Stromeyer isolated the metal and identified it as a new element, which he named cadmium, in reference to the ancient Greek word "kadmeia", which relates to a region of Asia Minor known for its abundance of zinc ores.

After its discovery, cadmium was initially used on a small scale in pigments to color glass and ceramics. However, its use ended up expanding over time into various industrial applications due to its unique properties, such as its ability to resist corrosion and absorb neutrons, making it useful in several areas, mainly in the battery industry. And where is cadmium found in the world?

The most important cadmium deposits in the world are generally associated with deposits of zinc ores, as cadmium is often found as a by-product of this type of mining. As China is currently the largest producer of zinc in the world, it automatically also becomes the largest producer of cadmium in the world by table. It has large deposits of zinc ore in several regions, including Shaanxi Province, Sichuan Province and the Xinjiang Autonomous Region.

Canada is another major producer of zinc and cadmium, where the Newfoundland and Labrador regions are especially known for their zinc ore deposits that contain cadmium as a by-product. Although not one of the largest producers of zinc, the United States still has deposits of zinc and cadmium in several regions, including the Zinc Triangle region of Missouri and the Franklin Furnace region of New Jersey. But where is cadmium most used?

Some rechargeable batteries, such as nickel-cadmium (NiCd) batteries, as the name suggests, contain cadmium. Although these batteries are less common today due to environmental concerns, they can still be found in some older electronic devices. This type of battery was very common in the past, widely used in a variety of electronic devices, from cell phones to digital cameras and power tools.

However, over time, Several reasons have led to the decline in the use of NiCd batteries and the preference for alternative battery technologies such as lithium-ion batteries. If you are a little older, you must remember that batteries were addictive, right? This is because the batteries used at the time were nickel-cadmium, and they were prone to the so-called "memory effect".

This means that if the battery was not completely discharged before being recharged, its total energy storage capacity would gradually decrease. This limited the efficiency and useful life of the batteries and required special care from users. But they also had a relatively low energy density compared to other battery technologies, such as lithium-ion batteries.

In other words, they stored less energy in relation to their weight than other batteries. But cadmium has gained strength with the solar industry. This is because cadmium telluride (CdTe) solar cells have become the second most common photovoltaic technology, behind crystalline silicon.

They have a low production cost compared to monocrystalline and polycrystalline silicon. This is partly due to the abundance of cadmium telluride, as well as the simplified manufacturing process for this type of cell. Unlike silicon photovoltaic cells, cadmium-based solar cells perform better at high temperatures and this makes them an attractive choice for regions with hot, sunny climates.

But wait, what does the carrot I said at the beginning of the video have to do with cadmium? Well, it is important to say that exposure to cadmium can have several adverse effects on human health, especially when it occurs at high levels or chronically. It is mainly known for being toxic to the kidneys.

When you have prolonged exposure to cadmium this can lead to problems such as kidney dysfunction, kidney failure and an increased risk of kidney stones. But it's not just ingestion, but inhaling cadmium vapors or dust can irritate the lungs and lead to respiratory problems such as chronic bronchitis and emphysema. And when you have prolonged exposure to inhaling cadmium vapors, this can increase the risk of more serious lung diseases.

It can end up accumulating in the bones over time, replacing calcium and weakening the bone structure and this can lead to problems such as osteoporosis and increase the risk of fractures. Not to mention the damage to the liver, interfering with its normal metabolic functions and leading to liver problems such as hepatitis and cirrhosis. It can also affect the central nervous system, causing symptoms such as headaches, dizziness, weakness and fatigue and in severe cases of cadmium poisoning, permanent neurological damage can occur.

In some studies, evidence has been presented that exposure to cadmium may increase the risk of certain types of cancer, including lung, prostate and kidney cancer. Therefore, it is classified as carcinogenic to humans by the International Agency for Research on Cancer, IARC. But if you're wondering what a carrot has to do with cadmium, it's because some studies show that there is an increased concentration of cadmium in vegetables such as carrots and even curly lettuce.

This is due to the increased use of fertilizers and pesticides, some of which have significant amounts of cadmium in their composition and eventually end up in our food. If you've come this far and liked the video, take the opportunity to subscribe. If you're not already subscribed, leave your like and turn on the notification bell.

If you find our content interesting, consider becoming a member to help us continue producing content here at platform and be remembered in our videos. So, did you know about the properties of cadmium? Have you ever had an electronic device that used a Nickel Cadmium battery?

Did you know about its negative effects on health? Leave it here in the comments and I want to know. Here you have two video options that you might like and that are worth checking out to expand your knowledge.

And if you want to contribute with us, Leave your like, subscribe to the channel, activate the bell and consider becoming a member of the channel.