Harmful ultra-violet radiation coming from the sun can cause

The correct answer is D) Dermal Cancer. UV radiation from the sun is the main environmental cause of skin cancer. UV-B in particular damages DNA in skin cells, producing mutations such as pyrimidine dimers that, if not repaired, lead to basal cell carcinoma, squamous cell carcinoma and melanoma.

Why the others are wrong:

• Liver cancer is linked mainly to hepatitis B and C infection, aflatoxin in contaminated food, and cirrhosis, not to sunlight.
• Brain cancer has weak links to ionizing radiation and genetic factors. UV radiation is not a recognised cause.
• Oral cancer is associated with tobacco (including chewing forms), betel quid and alcohol, not with UV exposure.

Core concept: carcinogenic agents and their target organs. For Mains GS III (environment), link this to ozone depletion. The Montreal Protocol (1987) was adopted to phase out ozone-depleting substances, because a thinner ozone layer lets more UV-B reach the surface.

Trap: aspirants often mix UV with ionizing radiation (X-rays, gamma rays), which is linked to leukaemia and thyroid cancer. Keep the two categories separate.