Thorium's Pollution Potential: Is It Safe Or Not?

Thorium is a naturally occurring radioactive metal found in soil, rock, water, plants, and animals. It is formed by the radioactive decay of uranium and is used in various industrial processes, such as the production of ceramics, welding rods, and nuclear reactions. While it is present in the environment at low levels, human activities such as mining and industrial processing can lead to increased exposure and environmental contamination. This is particularly true for individuals living near thorium-mining areas or certain legacy industrial facilities, as well as workers in processing plants, who may face elevated health risks, including an increased risk of cancer.

Thorium is a naturally occurring radioactive metal found in soil, rock, water, plants and animals

Thorium (chemical symbol Th) is a naturally occurring radioactive metal discovered in 1828 by Swedish chemist Jons Jakob Berzelius. It is found in small amounts in most rocks and soils, where it is about three times more abundant than uranium. Soil contains an average of around 6 parts per million (ppm) of thorium. It is also found in water, plants, and animals. Thorium is formed by the radioactive decay of uranium and is present in minerals such as monazite, thorite, and thorianite. It is a weakly radioactive, silvery-white metal that tarnishes olive grey when exposed to air, forming thorium dioxide.

Thorium has various applications due to its unique properties. It has been used in lantern mantles for its brightness, welding rods for improved burning, and ceramics for its colouring properties. Additionally, thorium tetrafluoride is used in multilayered optical coatings as an anti-reflection material. Mag-Thor alloys, or thoriated magnesium, have been utilized in some aerospace applications, although concerns over radioactivity have led to a phase-out of their use. Thorium also has potential as a fuel for generating nuclear energy.

While thorium is widespread in the environment, most people are not exposed to dangerous levels of the metal. However, individuals living near thorium-mining areas or facilities that manufacture thorium products may have increased exposure, especially if their water source is from a private well. Inhalation of thorium dust has been linked to an increased risk of developing lung and pancreatic cancer, and exposure to thorium has been associated with an elevated risk of bone cancer.

Thorium-based power reactor fuels have been explored for electricity generation, but they are not ideal for creating fissile material usable in explosive devices. The use of thorium as a primary energy source has been considered, but challenges remain due to the handling difficulties and detectability issues associated with its strong gamma radiation field. Nevertheless, thorium's abundance in nature and its potential as a nuclear fuel continue to make it an intriguing prospect for future energy exploration.

Thorium is used in household items like ceramics, welding rods, and gas lantern mantles

Thorium is a naturally occurring radioactive metal found in soil, rock, water, plants, and animals. It is formed by the radioactive decay of uranium. While thorium has various applications, including use in the nuclear industry, it is also used in some household items.

Thorium is used in the production of ceramics, with its colouring properties making it useful in ceramic glazes. Uranium was historically used in the glaze of some older ceramic wares, but this has been replaced in modern times with safer alternatives. However, some older ceramics may still contain thorium, and a radiation counter is required to confirm its presence.

Thorium is also used in gas lantern mantles, also known as "Welsbach mantles" or "Auerlicht", invented by Austrian chemist Carl Auer von Welsbach in 1884. The mantles are produced by dipping a meshed fabric into a solution of thorium nitrate, drying it, coating it with lacquer, and then fashioning it into either a soft or hard mantle. When fuel is burned inside the mantle, the heating causes the thorium to emit an incandescent glow.

In addition to the above, thorium is also used in welding rods, which burn better with small amounts of added thorium. While thorium is present in the environment and most people are not exposed to dangerous levels, those living near thorium-mining areas or facilities that manufacture thorium products may have increased exposure. It is recommended that household items containing thorium, such as older ceramics and gas lantern mantles, be retired from use to avoid unnecessary exposure.

People who live near thorium-mining areas or facilities that manufacture thorium products may be exposed to higher levels of the metal

Thorium is a naturally occurring radioactive metal found in soil, rock, water, plants, and animals. It is formed by the radioactive decay of uranium. While it is widespread in the environment, most people are not exposed to dangerous levels of the metal.

However, people residing near thorium-mining areas or facilities that manufacture thorium products may be exposed to heightened levels of the metal. This is due to the potential release of thorium into the air, water, or soil during the mining and refining processes. If not properly controlled, wind and water can introduce thorium waste products, such as mill tailings, into the wider environment.

The primary routes of exposure to thorium are inhalation, intravenous injection, ingestion, and absorption through the skin. Inhaling thorium dust has been linked to an increased risk of lung and pancreatic cancer, with evidence suggesting a higher likelihood of bone cancer as well. Thorium may enter the body through contaminated water sources, especially if an individual's water supply comes from a private well.

Additionally, household items such as older ceramic wares with uranium and thorium glazes or gas lantern mantles may contain thorium. While these items generally do not pose serious health risks, it is recommended to discontinue their use as a precautionary measure.

It is important to note that analytical laboratories can test water for thorium content, and radiation counters can be used to detect the presence of thorium in ceramics.

Thorium has been linked to an increased risk of lung, bone, and pancreatic cancer

Thorium is a naturally occurring radioactive metal found in soil, rock, and water. It is formed by the radioactive decay of uranium. While most people are not exposed to dangerous levels of the metal, those living near thorium-mining areas or facilities that manufacture products with thorium may have increased exposure, especially if their water comes from a private well.

Intravenous injection is another primary method of exposure to thorium, and studies have found that patients who received intravascular injections of Thorotrast, a contrast agent used in medical radiology until the 1950s, had an increased risk of liver tumors. Once injected, Thorotrast remains in the body, resulting in lifelong exposure to thorium.

In addition to injections and inhalation, thorium exposure can occur through ingestion and absorption through the skin. More than 2.5 million people worldwide were exposed to thorium in Thorotrast between 1930 and 1950. While household items containing thorium, such as older ceramics and gas lantern mantles, generally do not pose serious health risks, they should be retired from use to avoid unnecessary exposure.

Thorium waste from rare earth processing can contaminate the environment and pose health risks to exposed organisms

Thorium is a naturally occurring radioactive metal found in soil, rock, and water. It is formed by the radioactive decay of uranium. While thorium is widespread in the environment, most people are not exposed to dangerous levels of the metal. However, people residing near thorium-mining areas or facilities that manufacture products with thorium may experience increased exposure, especially if their water source is a private well.

Thorium is also a byproduct of rare earth processing. Rare earth processing is an environmentally hazardous operation due to the production of mountains of toxic waste, with high risks of environmental and health hazards. For every ton of rare earth produced, the mining process yields 13kg of dust, 9,600-12,000 cubic meters of waste gas, 75 cubic meters of wastewater, and one ton of radioactive residue. The Bayan-Obo mine in China, the largest rare earth mine globally, has produced over 70,000 tons of radioactive thorium stored in a tailing pond. This pond lacks proper lining, allowing its contents to seep into the groundwater, which will eventually reach the Yellow River, a primary source of drinking water.

Thorium-containing waste generated during rare earth processing requires careful waste management. If not properly controlled, wind and water can introduce the tailings into the wider environment, leading to contamination. This contamination can occur through dust drift or tailing dam bursts, posing severe threats to exposed organisms in the environment.

Exposure to thorium, especially through inhalation or injection, can result in adverse health effects. Studies have found an increased risk of liver tumors among individuals who received intravascular injections of Thorotrast, a contrast agent containing thorium. Additionally, inhaling thorium dust increases the risk of lung and pancreatic cancer. Thorium exposure also elevates the risk of bone cancer, as thorium may be stored in bones for many years.

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