RADIATION
INTRODUCTION
Radiation is a form of energy emitted from natural and artificial sources, which can have
significant impacts on human health. While radiation is used beneficially in medicine, industry,
and energy production, excessive or uncontrolled exposure poses serious public health risks.
Public health efforts focus on minimizing exposure, preventing health risks, and ensuring safe
practices to protect populations from the harmful effects of radiation.
TYPES OF RADIATION
Non-ionising radiation: Such as visible light, signals from mobile phones and radio waves
Ionizing radiation: Such as radiation emissions from uranium ore and high frequency waves in
the electromagnetic spectrum (such as X-rays)
Each type of ionising radiation is capable of disrupting stable atoms and causing them to have
an imbalance of charge (ionisation). This can cause chemical changes in living matter which may
cause harm to people’s health, depending on the radiation dose received.
Ionising radiation
Unstable atoms in a material are said to ‘decay’ giving out ionising radiation in the process. The
property of a material to decay and emit ionising radiation is called radioactivity and the
material is said to be radioactive. As the unstable atoms in a radioactive material decay the
atoms change to another form.
The time taken for half the unstable atoms in a material to decay and change is known as the
half-life. Each radioactive material has its own half-life. These vary from less than a few seconds
to more than thousands of years.
There are 3 main types of ionising radiation:
i. alpha (α),
ii. beta (β)
iii. gamma (γ).
Alpha and beta radiations are particles, while gamma radiation is a wave similar to X-rays.
These forms of radiation differ in their ability to penetrate into the body or other materials and
also in their ability to cause harm to people.
Alpha particles
As they are relatively big, heavy and slow, alpha particles are not able to penetrate very far
through materials. They are stopped by a few centimetres of air or a sheet of paper and even
by the dead layer of skin on the outside of our bodies.
As they usually cannot penetrate into the body, alpha particles do not pose a significant hazard
from outside the body. However, radioactive materials emitting alpha particles can get into the
body by inhalation, ingestion or through open wounds. They can then damage tissue and have a
greater potential to cause cancer than beta particles and gamma rays.
Beta particles
These are relatively light, small and fast, so they may travel several metres in air and can
penetrate through exposed skin. Consequently, beta particles can present a hazard from inside
or outside the body. They can be stopped by thin sheets of aluminium or perspex.
Gamma rays
These rays have no weight and can penetrate through the body, depositing some of their
energy on the way and so causing harm. Gamma rays are therefore a hazard both inside and
outside the body.
They can be stopped or exposure can be reduced by the use of thick, heavy shielding.
PUBLIC HEALTH ISSUE
A major public health concern regarding radiation is the potential for increased cancer risk due
to exposure to ionizing radiation, which can damage DNA and lead to mutations that may
develop into cancerous cells, particularly from sources like medical imaging, nuclear power
plants, and exposure to radioactive materials in the environment; this risk is heightened with
high doses of radiation or prolonged exposure.
Key points about radiation as a public health issue:
Cancer risk:
The most significant health concern associated with radiation is the increased risk of developing
various cancers, including leukemia, thyroid cancer, breast cancer, and lung cancer, depending
on the type and dose of radiation received.
Sources of radiation exposure:
Medical procedures: Medical imaging like CT scans and fluoroscopies can expose patients to
significant radiation doses.
Nuclear power plants: Accidents at nuclear power plants can release large amounts of
radioactive material into the environment.
Environmental contamination: Radioactive materials from natural sources or past nuclear
incidents can contaminate soil and water, leading to exposure through ingestion or inhalation.
Occupational exposure: Workers in industries like nuclear power or medical imaging may be
exposed to higher levels of radiation due to their occupation.
Vulnerable populations: Children and pregnant women are particularly sensitive to the effects
of radiation due to their rapidly dividing cells.
Causes of radiation
Radiation can originate from both natural and artificial sources. Understanding these sources is
crucial for assessing risks and implementing effective public health measures. Below is a
detailed explanation of the causes of radiation:
1. Natural Sources of Radiation
Natural radiation, also known as background radiation, comes from environmental sources and
is present everywhere. It includes:
Cosmic Radiation
-Originates from outer space, including the sun and other celestial bodies.
- Intensity increases at higher altitudes (e.g., during air travel or in mountainous regions).
- Example: Cosmic rays contribute to a significant portion of natural radiation exposure.
Terrestrial Radiation:
- Emitted by radioactive elements in the Earth’s crust, such as uranium, thorium, and radon.
- Radon gas, a decay product of uranium, is a major source of indoor radiation exposure.
- Example: Radon seeping into homes from the ground is a leading cause of lung cancer in non-
smokers.
Internal Radiation:
- Radioactive elements like potassium-40 and carbon-14 are naturally present in the human
body.
- These elements contribute to low-level internal radiation exposure.
2. Artificial (Man-Made) Sources of Radiation
Artificial radiation is generated through human activities and technologies. It includes:
Medical Applications:
-Diagnostic Procedures: X-rays, CT scans, and fluoroscopy use ionizing radiation to create
images of the body.
- Radiation Therapy: High doses of radiation are used to treat cancer by destroying malignant
cells.
- Example: A single CT scan can expose a patient to more radiation than natural sources in a
year.
Nuclear Power Plants:
- Nuclear reactors produce energy by splitting uranium atoms, releasing radiation in the
process.
- Accidents (e.g., Chernobyl, Fukushima) can lead to large-scale radiation release.
- Example: The Fukushima disaster in 2011 released radioactive materials into the
environment.
Industrial Applications
-Mining and Processing: Uranium mining and processing expose workers to radioactive
materials.
- Manufacturing: Industries use radiation for quality control, sterilization, and material testing.
- Example: Radiation is used to sterilize medical equipment and food products.
Nuclear Weapons Testing:
- Explosions from nuclear weapons testing release large amounts of radioactive materials into
the atmosphere.
- Fallout from these tests can contaminate soil, water, and food supplies.
- Example: The nuclear tests conducted during the Cold War left a legacy of environmental
contamination.
Consumer Products:
- Some household items contain small amounts of radioactive materials (e.g., smoke detectors
with americium-241).
- Electronic devices like cell phones and microwaves emit non-ionizing radiation.
- Example: Prolonged use of electronic devices may contribute to low-level radiation exposure.
3. Occupational Exposure:
Certain occupations involve higher risks of radiation exposure:
- Healthcare Workers: Radiologists, nuclear medicine technicians, and dentists who use X-rays.
- Nuclear Industry Workers: Employees in nuclear power plants, uranium mines, and waste
disposal facilities.
- Researchers: Scientists working with radioactive materials in laboratories.
- Airline Crews: Frequent exposure to cosmic radiation at high altitudes.
4. Environmental Disasters
- Nuclear Accidents: Accidents at nuclear power plants or research facilities can release large
amounts of radiation.Example: The Chernobyl disaster in 1986 caused widespread radiation
contamination.
- Improper Waste Disposal: Radioactive waste from medical, industrial, and nuclear facilities
can contaminate the environment if not disposed of safely. Example: Leakage from radioactive
waste storage sites can pollute groundwater.
5. Lifestyle Factors
Living in High-Radon Areas: Radon gas can accumulate in homes, especially in basements and
poorly ventilated areas.
-Frequent Air Travel: Passengers and crew are exposed to higher levels of cosmic radiation
during flights.
- Use of Electronic Devices: Prolonged exposure to non-ionizing radiation from devices like cell
phones and laptops.
Prevention and Control Measures of Radiation
Radiation exposure poses significant health risks, but effective prevention and control measures
can minimize these risks. These measures involve a combination of regulatory frameworks,
technological advancements, public education, and emergency preparedness. Below is a
detailed explanation of the strategies to prevent and control radiation exposure:
1. Regulation and Monitoring
- Establish Exposure Limits: Set and enforce safe exposure limits for the general public and
occupational workers. Example: The International Commission on Radiological Protection (ICRP)
recommends annual dose limits of 1 mSv for the public and 20 mSv for radiation workers.
- Regular Monitoring: Continuously monitor radiation levels in the environment, workplaces,
and medical facilities. Example: Use dosimeters to measure personal radiation exposure in
high-risk occupations.
2. Public Education and Awareness
- Raise Awareness: Educate the public about radiation risks and safety measures through
campaigns, workshops, and school programs. Example: Inform homeowners about testing for
radon gas and mitigating high levels.
- Promote Safe Practices: Encourage safe use of electronic devices and awareness of radiation
sources in daily life. Example: Advise limiting screen time and using hands-free devices to
reduce exposure to non-ionizing radiation.
3. Protective Equipment and Shielding
- Use of Shielding Materials: Install lead or concrete barriers in medical and nuclear facilities to
block radiation. Example: Lead aprons and thyroid shields are used during X-rays to protect
patients and healthcare workers.
- Personal Protective Equipment (PPE): Provide PPE such as gloves, goggles, and suits for
workers in high-risk occupations. Example: Nuclear power plant workers wear protective
clothing to minimize exposure.
4. Optimization of Medical Practices:
- Justification and Optimization: Ensure that medical radiation procedures are justified
(benefits outweigh risks) and optimized (lowest effective dose). Example: Use alternative
imaging methods like ultrasound or MRI when possible.
- Training for Healthcare Professionals: Train radiologists and technicians on safe radiation
practices and dose reduction techniques. Example: Implement protocols to minimize repeat
scans and unnecessary exposure.
5. Environmental Safety Measures
- Radon Mitigation:
Test homes and buildings for radon and implement mitigation systems (e.g., ventilation,
sealing cracks). Example: Install radon sump systems in basements to reduce indoor radon
levels.
- Safe Waste Disposal: Properly store and dispose of radioactive waste to prevent
environmental contamination. Example: Use secure containment facilities for nuclear waste
with long half-lives.
6. Emergency Preparedness and Response
- Develop Emergency Plans: Create and regularly update emergency response plans for nuclear
accidents or radiation leaks. Example: Establish evacuation routes and shelters in areas near
nuclear facilities.
- Conduct Drills and Training: Train emergency responders, healthcare workers, and the public
on radiation emergency protocols. Example: Simulate nuclear disaster scenarios to test
response readiness.
- Stockpile Medical Supplies: Maintain supplies of potassium iodide tablets and other
treatments for radiation exposure. Example: Distribute to populations near nuclear power
plants.
7. Technological Advancements:
- Improve Detection and Monitoring: Develop advanced tools for detecting and measuring
radiation levels in real-time. Example: Use drones equipped with radiation sensors to monitor
contaminated areas.
- Innovate in Medical Imaging: Invest in low-dose imaging technologies and AI-assisted
diagnostics to reduce radiation exposure. Example: Develop CT scanners that use significantly
lower doses without compromising image quality.
8. Global Collaboration and Policy Development
- International Standards: Adopt and enforce global radiation safety standards set by
organizations like the IAEA and WHO. Example: Implement the IAEA’s Basic Safety Standards in
national regulations.
- Share Knowledge and Resources: Collaborate on research, training, and resource sharing to
address radiation risks globally. Example: Provide technical and financial support to developing
countries for radiation safety programs.
