Dangers of electromagnetic waves

Question 1

Why may EM radiation be harmful to people ?

Answer 1

enter tissues, often harmless but effects of each type of radiation are based on how much energy the wave transfers

Low frequency waves like radio waves don’t transfer much energy and mostly pass through soft tissues without being absorbed

High frequency waves like UV, X-rays and gamma rays all transfer lots of energy and can cause lots of damage

UV radiation damages surface cells which can lead to sunburn and lead to skin to age prematurely

X rays and Gamma rays are types of ionising radiation ( enough energy to knock electrons off atoms ) -> cause gene mutations or cells destruction and cancer

Question 2

If they are so dangerous, why do we continue to use them ?

Answer 2

UV radiation , X-Rays and gamma rays can be harmful but also useful. Before use, we look at if benefits outweigh health risks - example of car accident

Question 3

What’s radiation dose ?

Answer 3

measure of the risk of harm from the body being exposed to radiation

Not a measure of the absorption of total amount of radiation

Risks depend on the total amount of radiation absorbed and how harmful the type of radiation is

A sievert is big so you’ll see doses in millisieverts 1000 mSc=v = 1 Sv

Question 4

What does a CT scan do ?

Answer 4

uses X rays and a computer to build a picture of inside of a persons body

Question 5

Head and chest radiation dose mSv

Answer 5

head - 2.0 mSv
Chest - 8.0 mSv

CT scan to chest, patient more likely to suffer damage to genes than if they had a head scan