What is Radon?

Radon is a radioactive gas that forms naturally when uranium, thorium, or radium, which are radioactive metals, break down in rocks, soil, and groundwater.

What is Radon?

About Radon

  • Radon is a radioactive gas that forms naturally when uranium, thorium, or radium, which are radioactive metals, break down in rocks, soil, and groundwater. 
  • It is an inert, colourless, and odourless gas.
  • Radon gas usually exists at very low levels outdoors, but the gas can accumulate in areas without adequate ventilation, such as underground mines.
  • Radon can get into homes and buildings through small cracks or holes and build up in the air.
  • Radon levels may be higher in homes that are well insulated, tightly sealed, and/or built on soil rich in the elements uranium, thorium, and radium.
  • As we breathe, these particles are deposited on the cells lining the airways, where they can damage DNA and potentially cause lung cancer.
  • It is the second-most important cause of lung cancer after smoking and the leading cause of lung cancer among non-smokers.
  • According to the WHO, radon is estimated to cause between 3% to 14% of all lung cancers in a country, depending on the national average radon level and smoking prevalence. 

Q1) What is radioactivity?

Radioactivity is the property of some unstable atoms (radionuclides) to spontaneously emit nuclear radiation, usually alpha particles or beta particles often accompanied by gamma-rays. This radiation is emitted when the nucleus undergoes radioactive decay and is converted into a different isotope which may, according to its number of neutrons and protons, be either radioactive (unstable) or non-radioactive (stable). This “daughter” nucleus will usually be of a different chemical element to the original isotope

Source: Explained: Radon a silent killer and second leading cause of lung cancer with 21,000 annual deaths

Latest UPSC Exam 2026 Updates

Last updated on January, 2026

→ Check out the latest UPSC Syllabus 2026 here.

→ Join Vajiram & Ravi’s Interview Guidance Programme for expert help to crack your final UPSC stage.

UPSC Mains Result 2025 is now out.

UPSC Notification 2026 is scheduled to be released on January 14, 2026.

UPSC Calendar 2026 has been released.

UPSC Prelims 2026 will be conducted on 24th May, 2026 & UPSC Mains 2026 will be conducted on 21st August 2026.

→ The UPSC Selection Process is of 3 stages-Prelims, Mains and Interview.

→ Prepare effectively with Vajiram & Ravi’s UPSC Prelims Test Series 2026 featuring full-length mock tests, detailed solutions, and performance analysis.

→ Enroll in Vajiram & Ravi’s UPSC Mains Test Series 2026 for structured answer writing practice, expert evaluation, and exam-oriented feedback.

→ Join Vajiram & Ravi’s Best UPSC Mentorship Program for personalized guidance, strategy planning, and one-to-one support from experienced mentors.

UPSC Result 2024 is released with latest UPSC Marksheet 2024. Check Now!

UPSC Toppers List 2024 is released now. Shakti Dubey is UPSC AIR 1 2024 Topper.

→ Also check Best UPSC Coaching in India

Vajiram Content Team
Vajiram Content Team
UPSC GS Course 2026
UPSC GS Course 2026
₹1,75,000
Enroll Now
GS Foundation Course 2 Yrs
GS Foundation Course 2 Yrs
₹2,45,000
Enroll Now
UPSC Mentorship Program
UPSC Mentorship Program
₹85000
Enroll Now
UPSC Sureshot Mains Test Series
UPSC Sureshot Mains Test Series
₹19000
Enroll Now
Prelims Powerup Test Series
Prelims Powerup Test Series
₹8500
Enroll Now
Enquire Now