Human Resources

Types of Nuclear Radiation



1) Alpha

  • Not penetrating in the outer layer of skin, but toxic inside the body

3) Gamma and X-ray

  • A high energy photon
  • Very penetrating and the most common external hazard to human body

2) Beta

  • Consists of fast moving electrons
  • Penetrating, depends on the energy of the source

4) Neutron

  • Very penetrating and very hazardous to human body


Physical Half-Life

Nuclear Substance Types of Radiation Half-life Use
Iodine 131 Beta and Gamma medium energy 8 days Medical research & hyperthyroid treatment
Phosphorus 32 Beta (high energy) 14 days Medical research
Iodine 125 Gamma (low energy) 60 days Medical research
Sodium 22 Beta and Gamma
(high energy)
2.6 years Physics research
Tritium (H-3) Beta (very low energy) 12.3 years Medical research
Americium 241 Alpha (high energy) 433 years Smoke detectors
Carbon 14 Beta (low energy) 5,730 years Medical research