Chapter 6: Radiation & Cancer

Question 1

Non-Ionizing Radiation

Answer 1

Heat, Sound, Radio, Visible

Generally SAFE

Question 2

Ionizing Radiation

Answer 2

Cause DNA damage by ionizing atoms (X-Ray, Nuclear Radiation)

Question 3

Is Ultraviolet light Ionizing radiation?

Answer 3

NO! It can BOTH heat and cause DNA damage by altering chemical bonds (cross linking DNA bases)

Question 4

What are the 3 forms of skin cancer?

Answer 4

Basal Cell
Squamous
Melanoma

Question 5

Which form of skin cancer rarely metastasizes?

Answer 5

Basal cell

Question 6

Which form of skin cancer metastasizes in 1/20 patients and is linked to sunlight exposure?

Answer 6

Squamous

Question 7

Which form of skin cancer has usually metastasized by the time of diagnosis?

Answer 7

Melanoma

Question 8

Which form of skin cancer appears most often on the legs and back, non-exposed areas?

Answer 8

Melanoma

Question 9

Why can melanomas appear in non-exposed areas?

Answer 9

Early childhood with severe sunburns, severe sunburns as an adult

Question 10

Which class of UV is associated with Skin Cancer? Why?

Answer 10

UVB

Breaks covalent bonds in DNA

Question 11

What compound has increased our exposure to UVB? Why?

Answer 11

Chlorofluorocarbons

Were used as refrigerants, but are now banned due to destruction of Ozone layer

Question 12

How does UVB cause DNA mutations?

Answer 12

Creating pyrimidine dimers in DNA

Question 13

What is the UVB signature in DNA? What gene is this signature in?

Answer 13

C-T substitutions at dipyrimidine sites

P-53 gene

Question 14

UVB

Answer 14

P-53 mutations
Apoptosis
Tumor promotion

Question 15

Is sunburn a protective mechanism against skin cancer?

Answer 15

YES! It is an attempt to destroy cells damaged by UV radiation

Question 16

Is UVA considered an initiator or promoter?

Answer 16

Promoter as it stimulates division

Question 17

Tanning Devices

Answer 17

Claim to be safer than sunlight because they use UVA to stimulate melanin production
People who use them have higher rates of skin cancer, than those who do not

Question 18

X-Rays

Answer 18

Very penetrating through the body

Decrease in lifespan due to death from cancers - especially Leukemias

Question 19

Nuclear radiation

Answer 19

Alpha particles
Beta particles
Gamma particles

Question 20

Which form of nuclear radiation has the most energy and penetration?

Answer 20

Gamma Particles

Question 21

Which form of nuclear radiation is the most damaging but least penetrating?

Answer 21

Alpha Particles

Question 22

Radon Gas

Answer 22

Alpha emitter

Little penetration

Question 23

Where does radon gas come from?

Answer 23

Radium and uranium

Question 24

What radioactive element does radon decay to?

Answer 24

Polonium

Question 25

Whee does radon gas in tobacco smoke come from?

Answer 25

Tobacco fertilizers continuing phosphate from crushed rocks w/ trapped radon gas

Question 26

Why is Leukemia rate highest post atomic bomb?

Answer 26

Not as common as other cancers & latent period is generally shorter than other cancers, so they are first to be seen

Question 27

Natural promoter event

Answer 27

Lymphocytes are stimulated to divide due to allergies and infection

Question 28

What nuclear event caused the largest numbers of cancers of the thyroid ever caused by one single event?

Answer 28

Chernobyl 400X the radiation from bombing Japan

Question 29

How does ionizing radiation cause cancer?

Answer 29

Initiating carcinogenesis by causing DNA damage

Question 30

Reactive Oxygen Species | Hydroxyl radical, hydrogen peroxide, superoxide

Answer 30

Produced in biological systems and can be damaging and mutational

Question 31

Enzyme systems

Answer 31

Neutralize free radicals and consume and synthesize molecules to scavenge them Prevents many diseases (cancer, heart disease)

Question 32

BERT

Answer 32

Background Equivalent Radiation Time

Question 33

How many days of BERTS add up to one Chest X-Ray?

Answer 33

10 days

Question 34

How many years of BERTS does the average smoked get from smoking one year?

Answer 34

10 years

Question 35

What radioactive element is present in cigarette smoke following the decay of radon gas?

Answer 35

Polonium

Question 36

Radiation

Answer 36

Energetic particles or waves | 90% of exposure is natural and we have evolved repair mechanism