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Biological effects of exposure to radiation

Radiation can harm either the whole body (somatic damage) or eggs and sperm (genetic damage). Its effects are more pronounced in cells that reproduce rapidly, such as the stomach lining, hair follicles, bone marrow, and embryos. This is why patients undergoing radiation therapy often feel nauseous or sick to their stomach, lose hair, have bone aches, and so on, and why particular care must be taken when undergoing radiation therapy during pregnancy.

Different types of radiation have differing abilities to pass through material ( [link] ). A very thin barrier, such as a sheet or two of paper, or the top layer of skin cells, usually stops alpha particles. Because of this, alpha particle sources are usually not dangerous if outside the body, but are quite hazardous if ingested or inhaled (see the Chemistry in Everyday Life feature on Radon Exposure). Beta particles will pass through a hand, or a thin layer of material like paper or wood, but are stopped by a thin layer of metal. Gamma radiation is very penetrating and can pass through a thick layer of most materials. Some high-energy gamma radiation is able to pass through a few feet of concrete. Certain dense, high atomic number elements (such as lead) can effectively attenuate gamma radiation with thinner material and are used for shielding. The ability of various kinds of emissions to cause ionization varies greatly, and some particles have almost no tendency to produce ionization. Alpha particles have about twice the ionizing power of fast-moving neutrons, about 10 times that of β particles, and about 20 times that of γ rays and X-rays.

A diagram shows four particles in a vertical column on the left, followed by an upright sheet of paper, a person’s hand, an upright sheet of metal, a glass of water, a thick block of concrete and an upright, thick piece of lead. The top particle listed is made up of two white spheres and two green spheres that are labeled with positive signs and is labeled “Alpha.” A right-facing arrow leads from this to the paper. The second particle is a red sphere labeled “Beta” and is followed by a right-facing arrow that passes through the paper and stops at the hand. The third particle is a white sphere labeled “Neutron” and is followed by a right-facing arrow that passes through the paper, hand and metal but is stopped at the glass of water. The fourth particle is shown by a squiggly arrow and it passes through all of the substances but stops at the lead. Terms at the bottom read, from left to right, “Paper,” “Metal,” “Water,” “Concrete” and “Lead.”
The ability of different types of radiation to pass through material is shown. From least to most penetrating, they are alpha<beta<neutron<gamma.

Radon exposure

For many people, one of the largest sources of exposure to radiation is from radon gas (Rn-222). Radon-222 is an α emitter with a half–life of 3.82 days. It is one of the products of the radioactive decay series of U-238 ( [link] ), which is found in trace amounts in soil and rocks. The radon gas that is produced slowly escapes from the ground and gradually seeps into homes and other structures above. Since it is about eight times more dense than air, radon gas accumulates in basements and lower floors, and slowly diffuses throughout buildings ( [link] ).

A cut-away image of the side of a house and four layers of the ground it rests on is shown, as well as a second cut-away image of a person’s head and chest cavity. The house is shown with a restroom on the second floor and a basement with a water heater as the first floor. Green arrows lead from the lowest ground layer, labeled “radon in ground water,” from the third ground layer, labeled “Bedrock” and “Fractured bedrock,” from the second layer, labeled “radon in well water,” and from the top layer, labeled “radon in soil to the inside of the basement area. In the smaller image of the torso, a green arrow is shown to enter the person’s nasal passage and travel to the lungs. This is labeled “Inhalation of radon decay products.” A small coiled, helical structure next to the torso is labeled “alpha particle” on one section where it has a starburst pattern and “Radiation damage to D N A” on another segment.
Radon-222 seeps into houses and other buildings from rocks that contain uranium-238, a radon emitter. The radon enters through cracks in concrete foundations and basement floors, stone or porous cinderblock foundations, and openings for water and gas pipes.

Radon is found in buildings across the country, with amounts depending on where you live. The average concentration of radon inside houses in the US (1.25 pCi/L) is about three times the levels found in outside air, and about one in six houses have radon levels high enough that remediation efforts to reduce the radon concentration are recommended. Exposure to radon increases one’s risk of getting cancer (especially lung cancer), and high radon levels can be as bad for health as smoking a carton of cigarettes a day. Radon is the number one cause of lung cancer in nonsmokers and the second leading cause of lung cancer overall. Radon exposure is believed to cause over 20,000 deaths in the US per year.

Questions & Answers

Important of chemistry
Caring Reply
8 physical and chemical properties of aluminium
bolatito Reply
Question 91 in chapter 4 (finding the molarity of Calcium hydroxide), the answer given is 1.22 M and I have repeated the calculations numerous times and I keep getting 0.0122 M. Which is correct?
Hope Reply
what are the types of heat changes in chemical reaction
Chancha Reply
potassium is element number what, what is it symbol, what is it atomic weight, what it boiling point?
Vincent Reply
It is element number 19,symbol is K
Amha
atomic weight 39.0983g/mol boiling point 1047.0K
Johnson
I need 5 different and 5 similarities between compound and mixture
Mahmood Reply
Please send me answers
Mahmood
Please send me answers
Mahmood
Please send me answers
Mahmood
what is matter
Arinze Reply
Matter is anything that occupied space
Rasidi
matter is anything that has mass and occupies space
Johnson
matter is anything that has mass and volume.
rafaela
matter is any thing that can that has mass
samuel
a plot of the atomic radius against atomic number shows a periodic variation with group 1elements occupying the peaks and group 4 the troughs.plot the graph
Ngoline Reply
what is the periodic table all about
Godstime Reply
yeah
samuel
it's about predicting the different types of matter around us and organizing them in an elegant way
William
what is boyle law
Daniel Reply
the law states that at a constant absolute temperature the volume of a fixed of a gas is inversely proportional to the pressure of the gas...
Johnson
write short not on paper chromAtogphy
Ujunwa Reply
I am sorry, I don't understand the question. Are you referring to photospectometry, a machine that uses lightwaves to determine the chemical composition of a substance? Instead of the "coffee filter and solvent" method which is more crude, but simple enough to understand basic concepts.
Melissa
what is esterification?
Darey Reply
Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester(-COOR) as the reaction product....
Johnson
pls i dont know chemistry wat shall i do?
Chancha
Please...what do you mean by you don't know chemistry..can you explain further
Johnson
I am afraid you may end up injuring yourself working with these chemical processes with limited lab experience. Please be extremely careful. Research chem analysis, precedure and equipment.
Melissa
Pls can I be enlighten about boys law on chemistry
samuel
how we Learn full periodic table
muhammad Reply
how
Imran
Hello guys am new here my name is Angel from Nigeria how are u guys doing?
Angel Reply
Gud am from Nigeria too my name is sav
Michael
And me too guyz
Nwafor
explain the atomic orbital
Masti Reply

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Source:  OpenStax, Chemistry. OpenStax CNX. May 20, 2015 Download for free at http://legacy.cnx.org/content/col11760/1.9
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