question: How does a large radiation source cause surrounding objects to become radioactive too?
comment: The clothes themselves aren't radioactive, per se, but they are contaminated with radioactive material. Particles, dust, even individual atoms of radioactive material can cling to the surface of things they come into contact with. As those contaminants decay they release radiation, but they can also be dislodged or transferred to people who come into contact with them, so they pose both a direct and indirect risk of harm from radiation.
passages: Here is a list of radioisotopes formed by the action of cosmic rays on the atmosphere; the list also contains the production mode of the isotope. "These data were obtained from the SCOPE50 report, see table 1.9 of chapter 1".
  
  Section::::Natural.:Activation products from cosmic rays.:Transfer to ground.
  
  The level of beryllium-7 in the air is related to the sun spot cycle, as radiation from the sun forms this radioisotope in the atmosphere. The rate at which it is transferred from the air to the ground is controlled in part by the weather.
  
  Section::::Natural.:Activation products from cosmic rays.:Applications of dating.
   Section::::Studies of low level radiation.
  
  Section::::Studies of low level radiation.:Very high natural background gamma radiation cancer rates at Kerala, India.
   Earth is constantly bombarded with primary cosmic rays, high energy charged particles — mostly protons and alpha particles. These particles interact with atoms in atmospheric gases, producing a cascade of secondary particles that may in turn interact and reduce their energies in many reactions as they pass through the atmosphere. By the time the cosmic ray cascade reaches the surface of Earth it is primarily composed of neutrons. When one of these particles strikes an atom it can dislodge one or more protons and/or neutrons from that atom, producing a different element or a different isotope of the original element. In rock and other materials of similar density, most of the cosmic ray flux is absorbed within the first meter of exposed material in reactions that produce new isotopes called cosmogenic nuclides. At Earth's surface most of these nuclides are produced by neutron spallation. 
   Natural radioactive elements are present in very low concentrations in Earth's crust, and are brought to the surface through human activities such as oil and gas exploration or mining, and through natural processes like leakage of radon gas to the atmosphere or through dissolution in ground water. Another example of TENORM is coal ash produced from coal burning in power plants. If radioactivity is much higher than background level, handling TENORM may cause problems in many industries and transportation.
  
  Section::::NORM in oil and gas exploration.
   Unlike the capsule source, the plate source emitting material must be on the surface to prevent attenuation by a container or self-shielding due to the material itself. This is particularly important with alpha particles which are easily stopped by a small mass. The Bragg curve shows the attenuation effect in free air.
  
  Section::::Unsealed sources.
   BULLET::::- Wet deposition is the removal of pollution plume components by the action of rain. The wet deposition of radionuclides in a pollution plume by a burst of rain often forms so called "hot spots" of radioactivity on the underlying surface.
   The collision cascade creates many more vacancies and interstitials in the material than equilibrium for a given temperature, and diffusivity in the material is dramatically increased as a result. This leads to an effect called radiation enhanced diffusion, which leads to microstructural evolution of the material over time. The mechanisms leading to the evolution of the microstructure are many, may vary with temperature, flux, and fluence, and are a subject of extensive study
   The neutron radiation serves to transmute the surrounding matter, often rendering it radioactive. When added to the dust of radioactive material released by the bomb itself, a large amount of radioactive material is released into the environment. This form of radioactive contamination is known as nuclear fallout and poses the primary risk of exposure to ionizing radiation for a large nuclear weapon.
   Radioactive cosmogenic Be is produced in the atmosphere of the Earth by the cosmic ray spallation of oxygen. Be accumulates at the soil surface, where its relatively long half-life (1.36 million years) permits a long residence time before decaying to boron-10. Thus, Be and its daughter products are used to examine natural soil erosion, soil formation and the development of lateritic soils, and as a proxy for measurement of the variations in solar activity and the age of ice cores. The production of Be is inversely proportional to solar activity, because increased solar wind during periods of high solar activity decreases the flux of galactic cosmic rays that reach the Earth. Nuclear explosions also form Be by the reaction of fast neutrons with C in the carbon dioxide in air. This is one of the indicators of past activity at nuclear weapon test sites.
   How are gamma rays and neutrons produced by cosmic rays? Incoming cosmic rays—some of the highest-energy particles—collide with the nucleus of atoms in the soil. When nuclei are hit with such energy, neutrons are released, which scatter and collide with other nuclei. The nuclei get "excited" in the process, and emit gamma rays to release the extra energy so they can return to their normal rest state. Some elements like potassium, uranium, and thorium are naturally radioactive and give off gamma rays as they decay, but all elements can be excited by collisions with cosmic rays to produce gamma rays. The HEND and Neutron Spectrometers on GRS directly detect scattered neutrons, and the gamma sensor detects the gamma rays.
   There is evidence that targeted cytoplasmic irradiation results in mutation in the nucleus of the hit cells. Cells that are not directly hit by an alpha particle, but are in the vicinity of one that is hit, also contribute to the genotoxic response of the cell population. Similarly, when cells are irradiated, and the medium is transferred to unirradiated cells, these unirradiated cells show bystander responses when assayed for clonogenic survival and oncogenic transformation. This is also attributed to the bystander effect.
  
  Section::::Demonstration.
   Section::::Radiation damage.
  
  The radiation damage event is defined as the transfer of energy from an incident projectile to the solid and the resulting distribution of target atoms after completion of the event. This event is composed of several distinct processes:
  
  BULLET::::1. The interaction of an energetic incident particle with a lattice atom
  
  BULLET::::2. The transfer of kinetic energy to the lattice atom giving birth to a primary knock-on atom
  
  BULLET::::3. The displacement of the atom from its lattice site
  
  BULLET::::4. The passage of the displaced atom through the lattice and the accompanying creation of additional knock-on atoms
   Radioactive scrap metal
  
  Radioactive scrap metal is created when radioactive material enters the metal recycling process and contaminates scrap metal.
  
  Section::::Overview.
  
  A "lost source accident" occurs when a radioactive object is lost or stolen. Such objects may appear in the scrap metal industry if people mistake them for harmless bits of metal. The International Atomic Energy Agency has provided guides for scrap metal collectors on what a sealed source might look like. The best known example of this type of event is the Goiânia accident, in Brazil.
   When radioactive contamination is being measured or mapped "in situ", any location that appears to be a point source of radiation is likely to be heavily contaminated. A highly contaminated location is colloquially referred to as a "hot spot." On a map of a contaminated place, hot spots may be labeled with their "on contact" dose rate in mSv/h. In a contaminated facility, hot spots may be marked with a sign, shielded with bags of lead shot, or cordoned off with warning tape containing the radioactive trefoil symbol.
   Section::::Environmental.:Movement of colloids.
  
  While binding of a metal to the surfaces of the soil particles can prevent its movement through a layer of soil, it is possible for the particles of soil which bear the radioactive metal can migrate as colloidal particles through soil. This has been shown to occur using soil particles labeled with Cs, these have been shown to be able to move through cracks in the soil.
  
  Section::::Environmental.:Movement of colloids.:Normal background.
   The emission can be from black-body radiation or any other radiative mechanism. Since all materials emit black-body radiation (unless they are totally reflective or at absolute zero), this source for radiation pressure is ubiquitous but usually very tiny. However, because black-body radiation increases rapidly with temperature (according to the fourth power of temperature as given by the Stefan–Boltzmann law), radiation pressure due to the temperature of a very hot object (or due to incoming black-body radiation from similarly hot surroundings) can become very significant. This becomes important in stellar interiors which are at millions of degrees.
   When a high-energy particle from outer space ("primary" cosmic ray) encounters Earth, its first interaction is usually with an air molecule at an altitude of 30 km or so. This encounter causes the air molecule to split into smaller pieces, each having high energy. The smaller pieces are called "secondary" cosmic rays, and they in turn hit other air molecules resulting in more secondary cosmic rays. The process continues and is termed an "atmospheric cascade". If the primary cosmic ray that started the cascade has energy over 500 MeV, some of its secondary byproducts (including neutrons) will reach ground level where they can be detected by neutron monitors.
   BULLET::::- Cosmic rays come from all directions and consist of approximately 85% protons, 14% alpha particles, and 1% heavy ions, together with x-ray and gamma-ray radiation. Most effects are caused by particles with energies between 0.1 and 20 GeV. The atmosphere filters most of these, so they are primarily a concern for spacecraft and high-altitude aircraft.
  
  BULLET::::- Solar particle events come from the direction of the sun and consist of a large flux of high-energy (several GeV) protons and heavy ions, again accompanied by x-ray radiation.
   Section::::Cosmic effects of radiation pressure.:Clouds of dust and gases.
  
  The gravitational compression of clouds of dust and gases is strongly influenced by radiation pressure, especially when the condensations lead to star births. The larger young stars forming within the compressed clouds emit intense levels of radiation that shift the clouds, causing either dispersion or condensations in nearby regions, which influences birth rates in those nearby regions.
  
  Section::::Cosmic effects of radiation pressure.:Clusters of stars.
   Since the amount of radiation emerging from the opposite side of the material can be detected and measured, variations in this amount (or intensity) of radiation are used to determine thickness or composition of material.
  
  Section::::Radiographic cameras.:Torch design.
  
  One design is best thought of as being like a torch. The radioactive source is placed inside a shielded box, a hinge allows part of the shielding to be opened exposing the source, allowing photons to exit the radiography camera.
   Particles subject to bombardment by sufficiently energetic particles, like those found in cosmic rays, also experience the transmutation of atoms of one kind into another. These spallation effects can alter the trace element isotopic composition of specimens in ways which allow researchers to deduct the nature of their exposure in space.
   Radiogenic heating occurs as a result of the release of heat energy from radioactive decay during the production of radiogenic nuclides. Along with heat from the outer core of the Earth, radiogenic heating occurring in the mantle make up the two main sources of heat in the Earth's interior. Most of the radiogenic heating in the Earth results from the decay of the daughter nuclei in the decay chains of uranium-238 and thorium-232, and potassium-40.
  
  Section::::See also.
  
  BULLET::::- Geoneutrino
  
  BULLET::::- Radiometric dating
  
  BULLET::::- Stable nuclide
  
  Section::::External links.
   Most of the natural neutron background is a product of cosmic rays interacting with the atmosphere. The neutron energy peaks at around 1 MeV and rapidly drops above. At sea level, the production of neutrons is about 20 neutrons per second per kilogram of material interacting with the cosmic rays (or, about 100–300 neutrons per square meter per second). The flux is dependent on geomagnetic latitude, with a maximum near the magnetic poles. At solar minimums, due to lower solar magnetic field shielding, the flux is about twice as high vs the solar maximum. It also dramatically increases during solar flares. In the vicinity of larger heavier objects, e.g. buildings or ships, the neutron flux measures higher; this is known as "cosmic ray induced neutron signature", or "ship effect" as it was first detected with ships at sea.
   Hormesis remains largely unknown to the public. Government and regulatory bodies disagree on the existence of radiation hormesis and research points to the "severe problems and limitations" with the use of hormesis in general as the "principal dose-response default assumption in a risk assessment process charged with
  
  ensuring public health protection."
   Oil and gas TENORM and/or NORM is created in the production process, when produced fluids from reservoirs carry sulfates up to the surface of the Earth's crust. Some states, such as North Dakota, uses the term "diffuse NORM". Barium, calcium and strontium sulfates are larger compounds, and the smaller atoms, such as radium-226 and radium-228, can fit into the empty spaces of the compound and be carried through the produced fluids. As the fluids approach the surface, changes in the temperature and pressure cause the barium, calcium, strontium and radium sulfates to precipitate out of solution and form scale on the inside, or on occasion, the outside of the tubulars and/or casing. The use of tubulars in the production process that are NORM contaminated does not cause a health hazard if the scale is inside the tubulars and the tubulars remain downhole. Enhanced concentrations of the radium 226 and 228 and the daughter products such as lead-210 may also occur in sludge that accumulates in oilfield pits, tanks and lagoons. Radon gas in the natural gas streams concentrate as NORM in gas processing activities. Radon decays to lead-210, then to bismuth-210, polonium-210 and stabilizes with lead-206. Radon decay elements occur as a shiny film on the inner surface of inlet lines, treating units, pumps and valves associated with propylene, ethane and propane processing systems.
  
presuppositions: Radiation sources cause surrounding objects to be radioactive too.  Objects become radioactive if near a radioactive source.
corrections: Surrounding objects don't become radioactive, however they are coated with radioactive material temporarily.  The objects don't become radioactive but they carry radioactive particles.
raw_presuppositions: Radiation sources cause surrounding objects to be radioactive too.  Objects become radioactive if near a radioactive source.
raw_corrections: Surrounding objects don't become radioactive, however they are coated with radioactive material temporarily.  The objects don't become radioactive but they carry radioactive particles.