Electromagnetic waves can be harmful to the human body. Explain how three different types of electromagnetic radiation can cause harm, and for each one state a use that benefits society despite this risk.

Gamma rays: high‑energy photons can ionise atoms in cells, causing DNA damage and mutations, which may lead to cancer.
Use: they are employed in radiotherapy to kill tumour cells and in sterilising medical equipment.

Ultraviolet (UV) radiation: UVB and UVC can damage skin cells, cause sunburn, eye cataracts and skin cancer.
Use: UV lamps are used for energy‑efficient lighting, disinfecting water and for artificial sun‑tanning.

X‑rays: ionising radiation that can damage tissues and cause cataracts or other health effects.
Use: X‑ray imaging is used to diagnose fractures and internal injuries.

Microwaves: non‑ionising radiation that can heat tissues, potentially causing burns or heating of the brain.
Use: microwaves are used in microwave ovens to cook food.

Infrared radiation: can raise skin temperature, leading to burns or heat‑related eye damage.
Use: infrared lamps are used for therapeutic heating and in industrial drying processes.