10.7 Medical applications and biological effects of nuclear radiation (Page 5/18)

University physics volume 3 Page 5 / 18

Typical doses received during diagnostic x-ray exams
Procedure	Effective Dose (mSv)
Chest	0.02
Dental	0.01
Skull	0.07
Leg	0.02
Mammogram	0.40
Barium enema	7.0
Upper GI	3.0
CT head	2.0
CT abdomen	10.0

What mass of $^{137} Cs$ Escaped chernobyl?

The Chernobyl accident in Ukraine (formerly in the Soviet Union) exposed the surrounding population to a large amount of radiation through the decay of

^{137} Cs

. The initial radioactivity level was approximately

A = 6.0 MCi .

Calculate the total mass of

^{137} Cs

involved in this accident.

Strategy

The total number of nuclei, N , can be determined from the known half-life and activity of

^{137} Cs

(30.2 y). The mass can be calculated from N using the concept of a mole.

Solution

Solving the equation

A = \frac{0.693 N}{t_{1 / 2}}

for N gives

N = \frac{A t_{1 / 2}}{0.693} .

Entering the given values yields

N = \frac{(6.0 MCi) (30.2 y)}{0.693} .

To convert from curies to becquerels and years to seconds, we write

N = \frac{(6.0 \times 10^{6} Ci) (3.7 \times 10^{10} Bq/Ci) (30.2 y) (3.16 \times 10^{7} s/y)}{0.693} = 3.1 \times 10^{26} .

One mole of a nuclide $^{A} X$ has a mass of A grams, so that one mole of $^{137} Cs$ has a mass of 137 g. A mole has $6.02 \times 10^{23}$ nuclei. Thus the mass of $^{137} Cs$ released was

m = (\frac{137 g}{6.02 \times 10^{23}}) (3.1 \times 10^{26}) = 70 \times 10^{3} g = 70 kg .

Significance

The mass of

^{137} Cs

involved in the Chernobyl accident is a small material compared to the typical amount of fuel used in a nuclear reactor. However, approximately 250 people were admitted to local hospitals immediately after the accident, and diagnosed as suffering acute radiation syndrome. They received external radiation dosages between 1 and 16 Sv. Referring to biological effects in [link] , these dosages are extremely hazardous. The eventual death toll is estimated to be around 4000 people, primarily due to radiation-induced cancer.

Got questions? Get instant answers now!

Check Your Understanding Radiation propagates in all directions from its source, much as electromagnetic radiation from a light bulb. Is activity concept more analogous to power, intensity, or brightness?

power

Got questions? Get instant answers now!

Summary

Nuclear technology is used in medicine to locate and study diseased tissue using special drugs called radiopharmaceuticals. Radioactive tags are used to identify cancer cells in the bones, brain tumors, and Alzheimer’s disease, and to monitor the function of body organs, such as blood flow, heart muscle activity, and iodine uptake in the thyroid gland.
The biological effects of ionizing radiation are due to two effects it has on cells: interference with cell reproduction and destruction of cell function.
Common sources of radiation include that emitted by Earth due to the isotopes of uranium, thorium, and potassium; natural radiation from cosmic rays, soils, and building materials, and artificial sources from medical and dental diagnostic tests.
Biological effects of nuclear radiation are expressed by many different physical quantities and in many different units, including the rad or radiation dose unit.

Key equations

Atomic mass number	$A = Z + N$
Standard format for expressing an isotope	$_{Z}^{A} X$
Nuclear radius, where r ₀ is the radius of a single proton	$r = r_{0} A^{1 / 3}$
Mass defect	$Δ m = Z m_{p} + (A - Z) m_{n} - m_{nuc}$
Binding energy	$E = (Δ m) c^{2}$
Binding energy per nucleon	$B E N = \frac{E_{b}}{A}$
Radioactive decay rate	$- \frac{d N}{d t} = λ N$
Radioactive decay law	$N = N_{0} e^{− λ t}$
Decay constant	$λ = \frac{0.693}{T_{1 / 2}}$
Lifetime of a substance	$\bar{T} = \frac{1}{λ}$
Activity of a radioactive substance	$A = A_{0} e^{− λ t}$
Activity of a radioactive substance (linear form)	$ln A = − λ t + ln A_{0}$
Alpha decay	$_{Z}^{A} X \to_{Z - 2}^{A - 4} X +_{2}^{4} H e$
Beta decay	$_{Z}^{A} X \to_{Z + 1}^{A} X +_{−1}^{0} e + \bar{v}$
Positron emission	$_{Z}^{A} X \to_{Z - 1}^{A} X +_{+ 1}^{0} e + v$
Gamma decay	$_{Z}^{A} X * \to_{Z}^{A} X + γ$

Questions & Answers

how does Neisseria cause meningitis

Nyibol Reply

what is microbiologist

Muhammad Reply

what is errata

Muhammad

is the branch of biology that deals with the study of microorganisms.

Ntefuni Reply

What is microbiology

Mercy Reply

studies of microbes

Louisiaste

when we takee the specimen which lumbar,spin,

Ziyad Reply

How bacteria create energy to survive?

Muhamad Reply

Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments

_Adnan

But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?

Muhamad

they make spores

Louisiaste

what is sporadic nd endemic, epidemic

Aminu Reply

the significance of food webs for disease transmission

Abreham

food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.

Mark

explain assimilatory nitrate reduction

Esinniobiwa Reply

Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).

Elkana

This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products

Elkana

Examples of thermophilic organisms

Shu Reply

Give Examples of thermophilic organisms

Shu

advantages of normal Flora to the host

Micheal Reply

Prevent foreign microbes to the host

Abubakar

they provide healthier benefits to their hosts

ayesha

They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!

Mark

what is cell

faisal Reply

cell is the smallest unit of life

Fauziya

cell is the smallest unit of life

Akanni

Innocent

cell is the structural and functional unit of life

Hasan

is the fundamental units of Life

Musa

what are emergency diseases

Micheal Reply

There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️

_Adnan

define infection ,prevention and control

Innocent

I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life

Lubega

Heyy Lubega hussein where are u from?

_Adnan

en français

Adama

which site have a normal flora

ESTHER Reply

Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract

Safaa

skin

Asiina

skin,Oral,Nasal,GIt

Sadik

How can Commensal can Bacteria change into pathogen?

Sadik

How can Commensal Bacteria change into pathogen?

Sadik

all

Tesfaye

by fussion

Asiina

what are the advantages of normal Flora to the host

Micheal

what are the ways of control and prevention of nosocomial infection in the hospital

Micheal

what is inflammation

Shelly Reply

part of a tissue or an organ being wounded or bruised.

Wilfred

what term is used to name and classify microorganisms?

Micheal Reply

Binomial nomenclature

adeolu

Got questions? Join the online conversation and get instant answers!

Jobilize.com Reply

<< Chapter < Page Page > Chapter >>

Practice Key Terms 11

Read also:

Get Jobilize Job Search Mobile App in your pocket Now!

100% Free Mobile Applications
Receive real-time job alerts and never miss the right job again

Source: OpenStax, University physics volume 3. OpenStax CNX. Nov 04, 2016 Download for free at http://cnx.org/content/col12067/1.4

Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'University physics volume 3' conversation and receive update notifications?

Ask

	Engineering Communication MCQ By Steve Gibbs Start Quiz
	4 Neuroanatomy 04 Spinal Cord Brain Stem By Stephen Voron Start Quiz
	23 AP 23 Digestive System MCQ By OpenStax Start Quiz
	Young Economist MCQ Test By Robert Murphy Start Test
©flickr: U.S.	Biology Chapter 10 By Michael Sag Start Exam
	23 Biology 23 Protists MCQ By OpenStax Start Quiz
	Anthropology Aesthetics Culture By Richley Crapo Start Assignment
©flickr: Iqbal	Liver Cancer By Darlene Paliswat Start Test
©flickr:	Biology 1 By Jill Zerressen Start Quiz
	24 Biology 24 Fungi MCQ By OpenStax Start Quiz

10.7 Medical applications and biological effects of nuclear radiation (Page 5/18)

What mass of 137 Cs Escaped chernobyl?

Strategy

Solution

Significance

Summary

Key equations

Questions & Answers

Read also:

Get Jobilize Job Search Mobile App in your pocket Now!

What mass of $^{137} Cs$ Escaped chernobyl?