Radiation and Its Uses Pg. 680-682. Effects of Radiation Radioactive elements are potentially hazardous, but the effects are quite subtle The effects.

Radiation and Its UsesPg. 680-682

Effects of Radiation• Radioactive elements are potentially

hazardous, but the effects are quite subtle• The effects of exposure to radiation may

not be apparent for years!

Effects of Radiation• Radiation damage can be classified in two groups:

• Somatic Damage: damage to the organism itself, resulting in sickness or death

• Problems are seen• immediately if a massive dose of radiation is received• Takes years to appear if smaller doses are received, usually in the form

of cancer

•Genetic Damage: damage to the genetic machinery/material of the reproductive cells

•Creates problems that are seen in the offspring of the organism

Effects of Radiation

• Factors that affect the biological effects of radiation:• Energy of the radiation

• The higher the energy of the radiation, the more damage it can cause

• The penetrating ability of the radiation

Effects of Short-Term Exposures to Radiation

Rem indicates the danger the radiation poses for humans.

Dose (rem)

0-25

25-50

100-200

500

Clinical Effect

Nondetectable

Temporary decrease in white blood cell counts

Strong decrease in white blood cell counts

Death of half the exposed population w/in 30 days

Using Radiation to Help Us• Cancer Treatment

• Beams of gamma radiation are targeted at the growing tumor

• Problems with fighting cancer using radiation:• Can kill healthy cells

along with cancerous cells

• Cancerous cells in the middle of the tumor may be immune to the gamma radiation

• Common isotopes used:• Cobalt-60 and Cesium-137

Proton Therapy:

http://www.proton-therapy.org/index.html

http://www.niu.edu/protontherapy/index.shtml

Radioactive Tracers

• Radioactive Tracers = radioactive nuclides that can be introduced into a system so we can trace them throughout a process

Ways to use Radioactive tracers :

#1. Reading DNA

PET and brain activity.

normal Alzheimer’s

asymmetric scan indicates disease

normal

Ways to use Radioactive tracers : #2. Medical Diagnosis

•Other examples:

•Technetium-99m used to detect brain tumors and liver problems

•Phosphorus-32 used to detect skin cancer

•Patient drinks a sample with a small amount of radioactive iodine – 131

•Thyroid uses iodine to make thyroxine

•After two hours, uptake of iodine is measured by scanning with a radiation detector