Dangers of Radiation | Physics for GCSE/IGCSE - Year 11 PDF Download

Dangers of Radioactivity

• Ionizing radiation can harm human cells and tissues when exposed to high levels. This harm may manifest as cell death, tissue damage, mutations, or even the development of cancer.
• Cell death occurs when cells are unable to repair the damage caused by radiation, leading to their demise.
• Tissue damage refers to the harmful impact on organs and tissues due to radiation exposure.
• Mutations can result from radiation damaging the DNA of cells, potentially leading to genetic changes.
• Cancer can be a consequence of radiation-induced mutations that cause uncontrolled cell growth.
• Consequently, it is crucial to minimize the use of radiation to prevent these harmful effects on the human body.
• Despite the risks associated with radiation, its benefits in medical applications often outweigh the potential dangers.
• In medical contexts, the risks of untreated conditions can be greater than the risks associated with radiation therapy.
• The dangers of radiation are outweighed by the risks of untreated conditions
• For instance, in cases of life-threatening cancer, using radiotherapy is less risky than avoiding treatment

Tissue Damage

• Radiation is commonly utilized to eradicate cancerous cells
• However, improper targeting may harm healthy tissues, notably with high-energy radiation like gamma rays and X-rays

Mutations

• Ionization of DNA atoms from radiation can lead to DNA strand damage
• Cell death or mutation may occur due to damaged DNA, potentially resulting in tumor formation
• Cell mutations that replicate can lead to the development of tumors, exemplifying the risks of radiation exposure

Understanding Cancer and Radiation Exposure

• Cancer is a serious risk associated with radiation exposure. When exposed to ionizing radiation, the DNA in human cells can be damaged, potentially leading to mutations.

• Diagram showing the damage caused to DNA by ionizing radiation. Sometimes the cell is able to successfully repair the DNA, but incorrect repairs can cause a mutation.

Acute Symptoms of Radiation Exposure

• Acute radiation exposure can result in various severe symptoms:
  • Skin burns similar to severe sunburn
  • Reduction in white blood cell count, weakening the immune system
• These symptoms highlight the importance of handling radioactive sources with extreme care.
• It is crucial to handle radioactive sources with great care to ensure safety.

Safe Storage

Following certain simple procedures can help minimize the risks associated with handling radioactive sources:

• To reduce risks associated with radioactive sources, it's essential to store them in lead-lined containers and maintain a distance from individuals.
• Limit the duration of handling radioactive sources and promptly return them to their storage containers after use.
• While handling sources, maintain a safe distance from them whenever possible. Use tongs to handle sources at arm's length.
• Typically, gloves and safety glasses are unnecessary when using tongs to handle radioactive materials unless there's a risk of material leakage onto surfaces.

Disposing of Radioactive Waste

• A sample containing an isotope with a lengthy half-life will undergo decay at a slow pace.
  • Despite emitting a relatively low amount of radiation, it will remain radioactive for an extended period.
• Sources possessing extended half-life values pose a contamination risk for an extended duration.
• Radioactive waste characterized by a lengthy half-life is disposed of underground to mitigate the risk of environmental release.

Safety Precautions

These precautions are essential to safeguard individuals from the harmful effects of radiation exposure. Let's delve deeper into each of these safety measures:

• Shielded Storage: Radioactive sources, to minimize risks, should be stored within shielded containers like lead-lined boxes when not in use. This containment method ensures that radiation exposure is limited and controlled effectively.
• Personal Protective Equipment: When handling radioactive materials, it is imperative to wear appropriate protective gear, such as gloves and using tongs. These protective measures are crucial in maintaining a safe distance from the radioactive source, reducing the risk of direct contact and potential contamination.
• Protective Clothing: Wearing specialized protective clothing can serve as an additional barrier against radiation exposure. This clothing acts as a shield, preventing radioactive particles from coming into direct contact with the body and reducing the likelihood of contamination.
• Time Limitations: It is essential to restrict the duration for which a radioactive source is actively used. By limiting exposure time, the overall risk of potential harm from radiation is significantly reduced, ensuring the safety of individuals involved.

Regulating Exposure

• Regulate: Monitoring and limiting the amount of radiation individuals come into contact with.
• Sieverts: The unit used to measure the dose of radiation received by a person.
• One sievert signifies a substantial amount of radiation that can lead to acute radiation poisoning.
  • Radiation Poisoning: Severe health consequences resulting from exposure to high levels of radiation.
• On average, individuals typically receive around 3 milliSieverts (mSv) per year.
• To prevent over-exposure, radiation doses from various activities are carefully monitored.
• A dosemeter is utilized to gauge radiation levels in specific areas, commonly worn by radiographers and individuals working with radiation.

Differences in Exposure

• The level of radiation a person is exposed to can be influenced by their job, habits, or where they live.
• Occupation: Certain occupations entail more exposure to radiation, such as nuclear industry workers.
• Lifestyle: Factors in one's lifestyle can also impact radiation levels they encounter.
• Location: Some regions have higher background radiation due to their proximity to radiation sources.
• Background Radiation: Areas closer to radiation sources experience elevated background radiation levels.
• Individuals working in nuclear-related fields receive higher doses, with the UK setting a yearly limit of 20 mSv for such employees.
  • The UK mandates a maximum annual radiation exposure of 20 mSv for personnel in the nuclear industry.
• The infographic below illustrates the varying radiation doses associated with different activities: