5 metals that are dangerous for humans and why

Heavy metals are natural components of the Earth’s interior. They have an unusually high atomic weight and density, five times greater than water. They can neither be destroyed nor degraded, and due to their extensive use in industrial, domestic, agricultural, medical, and technological equipment, they have slowly entered our bodies via air, water, and food. We have been extremely careless in dealing with these metals and have ignored their potential effects on the environment and human body. It is high time we raise awareness about these metals, which can lead to poisoning in humans.

This naturally occurring metal has caused environmental degradation and public health problems in many parts of the world. In industries, lead is mainly used for the production of lead-acid batteries for motor vehicles. It can also be found in other products such as pigments, paints, solder, stained glass, lead crystal glassware, ammunition, ceramic glazes, jewelry, toys, kohl, and sindoor. Younger children are especially affected by the toxic effects of lead and can suffer permanent consequences. Exposure to lead in adults increases the risks of high blood pressure, cardiovascular problems, and kidney damage.

Mercury is released into Earth’s air from various sources, including volcanic eruptions, weathering of rocks, and human activities. The main source remains human activities like burning coal, industrial processes, waste incinerators, and mining of metals. Once mercury is released, it is transformed into methylmercury by bacteria. It finds its way into our food chain through bioaccumulation in fish and shellfish. Mercury in our system impacts the central and peripheral nervous systems. The inhalation of mercury can affect our nervous, digestive, and immune systems.

Inorganic arsenic is found in the groundwater of various countries, including Argentina, Bangladesh, Cambodia, Chile, China, India, Mexico, Pakistan, the United States of America, and Vietnam, according to the World Health Organization. Drinking such water or consuming crops irrigated with such water is how arsenic enters our body. Along with that, arsenic is used as an alloying agent industrially. Both inorganic and organic arsenic are detrimental to our health, with the former being more toxic than the latter. Prolonged exposure to arsenic can cause poisoning, and cancers of the bladder, lungs, and skin.

This bluish-white metal occurs naturally in the earth’s crust and is mainly found in zinc ores. It was first discovered in Germany in 1817 and was used for its ability to produce brilliant colors of yellow, orange, and red. However, it soon came to be used in the production of nickel-cadmium (Ni-Cd) batteries and anti-corrosion coating on iron and steel. Cadmium exposure is common in industry workers and can even cause cancer. It affects the body’s cardiovascular, renal, gastrointestinal, neurological, reproductive, and respiratory systems.

Thallium can be found in pure form as well as mixed with other metals in alloy. It can also be found with bromine, chlorine, fluorine, and iodine to form salts. It exists in two chemical states: thallous and thallic. Thallium is mainly used in the production of electronic devices, switches, and closures. Until 1972, it was also used in the manufacture of rat poison but was later banned as it had adverse effects on humans too. Thallium can affect the nervous system, lungs, heart, liver, and kidneys.