Chapter 24.4, Problem 33SSC

Interpretation Introduction

Interpretation:

The fraction of radiation received of the minimum dose that is 25 rem by a person which causes temporary decrease in WBC population needs to be determined.

Concept introduction:

A radiation dose is refers to the radiation amount that is absorbed from a source. The units of amount of radiation are rad and rem. Here, rad refers to the radiation absorbed dose. This is the amount of radiation obtained from the absorption of 0.01 J energy per kg of tissue. When the dose in rads is multiplied by numerical factor, rem is obtained.

Explanation of Solution

The dose and effects on Humans is represented as follows:

Thus, when dose is 25-50, there is temporary decrease in the population of white blood-cell.

The maximum average annual radiation from the ground, air and buildings is 175 mrem/y or 0.175 rem/yr, 260 mrem/yr or 0.26 rem/y and 160 mrem/y or 0.16 rem/yr respectively.

The fraction of minimum dose when source of radiation is ground will be:

$\frac{0.175}{25}=0.007$

And, the fraction of minimum dose when source of radiation is air will be:

$\frac{0.26}{25}=0.0104$

Now, the fraction of minimum dose when source of radiation is buildings will be:

$\frac{0.16}{25}=0.0064$