Lead shielding refers to the use of

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

as a form of

radiation protection Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Exposu ...

shield A shield is a piece of personal armour held in the hand, which may or may not be strapped to the wrist or forearm. Shields are used to intercept specific attacks, whether from close-ranged weaponry like spears or long ranged projectiles suc ...

people or objects from

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infr ...

so as to reduce the effective dose. Lead can effectively attenuate certain kinds of radiation because of its high

density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

and high

atomic number The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of its atomic nucleus. For ordinary nuclei composed of protons and neutrons, this is equal to the proton number (''n''p) or the number of pro ...

; principally, it is effective at stopping

gamma ray A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

s and

x-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

Operation

Lead's high density is caused by the combination of its high atomic number and the relatively short bond lengths and atomic radius. The high atomic number means that more

electron The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...

s are needed to maintain a neutral charge and the short bond length and a small

atomic radius The atomic radius of a chemical element is a measure of the size of its atom, usually the mean or typical distance from the center of the nucleus to the outermost isolated electron. Since the boundary is not a well-defined physical entity, there ...

means that many atoms can be packed into a particular lead structure. Because of lead's density and large number of electrons, it is well suited to scattering x-rays and gamma-rays. These rays are

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless particles that can ...

s, a type of

boson In particle physics, a boson ( ) is a subatomic particle whose spin quantum number has an integer value (0, 1, 2, ...). Bosons form one of the two fundamental classes of subatomic particle, the other being fermions, which have half odd-intege ...

, which impart

energy Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and l ...

onto electrons when they come into contact. Without a shield, the electrons within a person's body would be affected, which could damage their

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

. When the radiation attempts to pass through lead, its electrons absorb and scatter the energy. Eventually though, the lead will degrade from the energy to which it is exposed. However, lead is not effective against all types of radiation. High energy electrons (including

beta radiation A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus, known as beta decay. There are two forms of beta decay, β− decay and � ...

) incident on lead may create

bremsstrahlung In particle physics, bremsstrahlung (; ; ) is electromagnetic radiation produced by the deceleration of a charged particle when deflected by another charged particle, typically an electron by an atomic nucleus. The moving particle loses kinetic ...

radiation, which is potentially more dangerous to tissue than the original radiation. Furthermore, lead is not a particularly effective absorber of

neutron radiation Neutron radiation is a form of ionizing radiation that presents as free neutrons. Typical phenomena are nuclear fission or nuclear fusion causing the release of free neutrons, which then react with nuclei of other atoms to form new nuclides— ...

Types

Lead is used for shielding in x-ray machines,

nuclear power plant A nuclear power plant (NPP), also known as a nuclear power station (NPS), nuclear generating station (NGS) or atomic power station (APS) is a thermal power station in which the heat source is a nuclear reactor. As is typical of thermal power st ...

s, labs, medical facilities, military equipment, and other places where radiation may be encountered. There is great variety in the types of shielding available both to protect people and to shield equipment and experiments. In gamma-spectroscopy for example, lead castles are constructed to shield the probe from environmental radiation. Personal shielding includes lead aprons (such as the familiar garment used during dental

x-rays An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

thyroid The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans, it is a butterfly-shaped gland located in the neck below the Adam's apple. It consists of two connected lobes. The lower two thirds of the lobes are connected by ...

shields, and lead gloves. There are also a variety of shielding devices available for laboratory equipment, including lead castles, structures composed of lead

brick A brick is a type of construction material used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a unit primarily composed of clay. But is now also used informally to denote building un ...

s, and lead ''pigs'', made of solid lead or lead-lined containers for storing and transporting radioactive samples. In many facilities where radiation is produced, regulations require construction with lead-lined plywood or drywall to protect adjoining rooms from scatter radiation.

Wear

A ''lead apron'' or ''leaded apron'' is a type of

protective clothing Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electr ...

that acts as a radiation shield. It is constructed of a thin rubber exterior and an interior of

in the shape of a hospital apron. The purpose of the lead apron is to reduce exposure of a hospital patient to

s to vital organs that are potentially exposed to

ionizing radiation Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, ionize atoms or molecules by detaching ...

during

medical imaging Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to revea ...

that uses x-rays (

radiography Radiography is an imaging technology, imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiog ...

fluoroscopy Fluoroscopy (), informally referred to as "fluoro", is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a surgeon to see t ...

computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

). Protection of the reproductive organs with a lead rubber apron is considered important because

changes to

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

cells of the patient may pass on genetic defects to the offspring of the patient, causing serious and unnecessary hardship for child and parents. The

gland is especially vulnerable to x-ray exposure. Care should be taken to place a lead apron over the thyroid gland before taking dental radiographs. Aprons used for dental imaging should include thyroid collars. However, in poorer or loosely regulated countries, possibly due to the cost of such equipment (approx. 40 USD), no such lead protection is given to the patients themselves, though the operators do get out of the x-ray room for their own safety. The correct thickness of lead-equivalent (Pbeq) wear will depend on how long and how often the person is working in an exposed environment. The minimum requirement is to wear 0.25 mm Pbeq when not behind lead shielding. In a theatre using

(e.g. orthopaedics, cardiology or

interventional radiology Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as Fluoroscopy, x-ray fluoroscopy, CT scan, computed tomography, magnetic resonance imaging, or ultraso ...

) 0.35 or 0.5 mm lead may be appropriate because of the higher KV employed, and on proximity to the primary beam.Livingstone RS, Varghese A, Keshava SN. A Study on the Use of Radiation-Protective Apron among Interventionists in Radiology. J Clin Imaging Sci 2018;8:34 File:Lead Apron worn by Dr Danny Sands.jpg, A rubber coated lead apron protects organs from exposure to x-rays. File:Mikael Häggström at radiology in 2019.jpg, Thyroid gland protection File:X-ray of the pelvis of a 22 months old male - Lauenstein.jpg,

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

of the hips with a testicle shield File:Tablier plombé contre les effets négatifs des rayons X dans un hôpital au Bénin 07.jpg, Lead apron against the negative effects of X-rays in a hospital in Benin

References

External links

{{Commons category, Lead radiation shielding
lead protection from radiation
Protective gear Radiation protection Nuclear physics Nuclear safety and security Radiobiology Lead Medical equipment

Operation

Types

Wear

See also

References

External links