Ionizing Radiation: Air Pollutant Or Not?

Ionizing radiation is a type of energy released by atoms in the form of electromagnetic waves or particles. It can be naturally occurring, such as in soil, water, and vegetation, or human-made, such as x-rays and gamma rays. While ionizing radiation has beneficial applications in medicine, industry, and research, it also poses health risks, including skin burns, acute radiation syndrome, and an increased risk of cancer. As air pollution continues to be a significant health concern in certain parts of the world, particularly in industrializing countries, it is important to understand the role of ionizing radiation as a potential air pollutant and its impact on human health.

Ionizing radiation is a type of energy released by atoms

When moving at relativistic speeds (near the speed of light), these particles have enough kinetic energy to be ionizing. For example, a typical alpha particle moves at about 5% of the speed of light, while an electron with 33 electronvolts (eV) (just enough to ionize) moves at about 1% of the speed of light. Alpha particles are helium nuclei ejected from the nucleus of an atom during radioactive decay, and energetic electrons are called beta particles. Natural cosmic rays are primarily made up of relativistic protons but also include heavier atomic nuclei like helium ions and HZE ions.

Ionizing radiation has many beneficial applications in medicine, industry, agriculture, and research. For example, in medicine, it is used in x-ray machines and computed tomography (CT) scanners. However, as the use of ionizing radiation increases, so does the potential for health hazards if not properly used or contained. Ionizing radiation can cause cell damage to living tissue and organ damage, and in high acute doses, it will result in radiation burns and radiation sickness. Lower-level doses over a more extended period can cause cancer.

External exposure to ionizing radiation can occur when airborne radioactive material, such as dust, liquid, or aerosols, is deposited on the skin or clothes. This type of radioactive material can often be removed from the body by washing. Exposure to ionizing radiation can also result from irradiation from an external source, such as medical radiation exposure from x-rays. People are exposed to natural sources of ionizing radiation, such as in soil, water, and vegetation, and indoor sources such as secondhand smoke from tobacco.

It can cause health issues such as skin burns and cancer

Ionizing radiation is a type of energy released by atoms that travel in the form of electromagnetic waves (gamma or X-rays) or particles (neutrons, beta or alpha). People are exposed to natural sources of ionizing radiation, such as in soil, water, and vegetation, as well as human-made sources, such as x-rays in medical devices. Radon, a naturally-occurring gas, emanates from rock and soil and is the main source of natural radiation. Every day, people inhale and ingest radionuclides from air, food, and water.

As the use of ionizing radiation increases, so does the potential for health hazards if not properly used or contained. Ionizing radiation can cause health issues such as skin burns and cancer. Acute health effects such as skin burns or acute radiation syndrome can occur when doses of radiation exceed very high levels. Skin reddening (erythema) is an example of a deterministic effect with a threshold dose of approximately 300 rad (3 Gy). When ionizing radiation interacts with cells, it can cause damage to the cells and genetic material (i.e., deoxyribonucleic acid, or DNA). If not properly repaired, this damage can result in cell death or potentially harmful changes in the DNA (i.e., mutations).

Low doses of ionizing radiation can increase the risk of longer-term effects such as cancer. The probability of an adverse health effect occurring is proportional to the radiation dose received. Studies have shown that radiation exposure increases the chance of getting cancer, and the risk increases as the dose increases. The higher the dose, the greater the risk. The US Environmental Protection Agency (EPA) bases its regulatory limits and non-regulatory guidelines for public exposure to low-level ionizing radiation on the linear no-threshold (LNT) model, which assumes that the risk of cancer due to low-dose exposure is proportional to the dose, with no threshold. In other words, cutting the dose in half cuts the risk in half.

It is important to note that the health effects of radiation depend on various factors, including the type of radiation, the radiation dose, the duration of exposure, the distance from the source, and individual sensitivity due to age and sex. While the risk of adverse health effects from air pollution is generally low for healthy individuals with limited exposure, those with pre-existing heart and lung disease, children, and older adults are more susceptible to the negative impacts of air pollution, even in the short term.

Radon, a naturally-occurring gas, is the main source of natural radiation

Radon is a naturally-occurring, colourless, odourless, and tasteless gas that is the main source of natural radiation. It is produced when uranium, thorium, or radium, which are radioactive metals, break down in rocks, soil, and groundwater. Radon occurs in significant quantities in three different chemical variations, or isotopes, but only two of these present a risk. Radon-222, a product of uranium-238 or radium-226 decay, is the most dangerous. It has a long decay rate, allowing it to accumulate indoors, and it is quite common due to varying concentrations of radium-226 in certain building materials.

Radon-220, a product of thorium-232 decay, often acts with radon-222 to be the main contributor to radiation exposure for the public. The primary danger comes not from radon itself, but from its decay products, known as radon daughters. These decay products can attach themselves to airborne dust particles, which can stick to the lungs and cause damage to lung tissue. Radon and its daughters are often the largest contributor to an individual's background radiation dose.

Radon is a contaminant that affects indoor air quality worldwide. The United States Environmental Protection Agency (EPA) has found that radon is the second most frequent cause of lung cancer, causing 21,000 lung cancer deaths per year in the United States. About 2,900 of these deaths occur among people who have never smoked. Radon is particularly concentrated in indoor workplaces, including offices, workshops, mines, and tunnels. Underground workplaces may have elevated radon levels due to geological conditions or limited ventilation.

Radon levels may also be high in groundwater, especially in areas of granite rock. Water from underground sources may contain significant amounts of radon, depending on the surrounding rock and soil conditions. Radon is released from water when the temperature is increased, pressure is decreased, and when water is aerated. The optimum conditions for radon release and exposure in domestic living occur during showering.

Ionizing radiation is used in medical devices, including x-ray machines

Ionizing radiation is a type of energy released by atoms in the form of electromagnetic waves or particles. It is a powerful form of energy with many beneficial applications in medicine, industry, agriculture, and research. The use of ionizing radiation in medicine includes diagnostic testing and treatment.

The medical use of ionizing radiation for diagnosis or treatment accounts for 98% of the population dose contribution from all human-made sources and represents 20% of the total population exposure. Annually, more than 4.2 billion diagnostic radiology examinations and 40 million nuclear medicine procedures are carried out worldwide.

While ionizing radiation has many beneficial applications, it is important to recognize the potential health hazards associated with its use. Exposure to high doses of ionizing radiation can alter body cells and DNA, leading to serious health issues such as skin burns, acute radiation syndrome, and an increased risk of cancer. Therefore, the use of ionizing radiation in medical devices must be carefully regulated to ensure it is properly used and contained.

To summarize, ionizing radiation is a powerful tool in medicine, with applications in diagnostic testing and treatment. Its use in medical devices, such as x-ray machines, has revolutionized healthcare. However, the potential risks associated with exposure to ionizing radiation must be carefully managed to ensure the benefits outweigh the risks.

Alpha and beta particles are types of ionizing radiation that can be harmful if ingested or inhaled

Ionizing radiation is a type of energy released by atoms in the form of electromagnetic waves or particles. It has many beneficial applications, including uses in medicine, industry, agriculture, and research. However, as the use of ionizing radiation increases, so do the potential health hazards if it is not properly used or contained.

Alpha and beta particles are types of ionizing radiation. Alpha particles are made up of two neutrons and two protons, while beta particles are small, fast-moving particles with a negative electrical charge that are emitted from an atom's nucleus during radioactive decay. Beta particles are more penetrating than alpha particles but are less damaging to living tissue and DNA. They can travel farther in air than alpha particles but can be stopped by a layer of clothing or a thin layer of a substance such as aluminum.

While alpha particles pose no direct or external radiation threat, they can pose a serious health threat if ingested or inhaled. The health effects of exposure to alpha particles depend on how a person is exposed. They lack the energy to penetrate even the outer layer of skin, so exposure to the outside of the body is not a major concern. However, inside the body, they can be very harmful. If alpha-emitters are inhaled, swallowed, or get into the body through a cut, they can damage sensitive living tissue and DNA. The way these large, heavy particles cause damage makes them more dangerous than other types of radiation. The ionizations they cause are very close together, and they can release all their energy in a few cells, resulting in more severe damage.

Beta particles are capable of penetrating the skin and causing damage such as skin burns. Beta-emitters are most hazardous when they are inhaled or swallowed. Some beta particles are emitted by certain unstable atoms, such as hydrogen-3 (tritium), carbon-14, and strontium-90.

In summary, alpha and beta particles are types of ionizing radiation that can be harmful if ingested or inhaled. The health effects of exposure depend on the type of particle, the route of exposure, and the amount of radiation. It is important to properly contain and shield oneself from these particles to prevent adverse health effects.

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