UV radiation explained: what it is and how to protect yourself

UV radiation from the sun is essential for human health in small doses, but overexposure can cause serious harm including skin cancer. Understanding UV levels and taking protective measures can significantly reduce health risks.

Ultraviolet (UV) radiation is a form of energy emitted by the sun that reaches Earth's surface every day. While some exposure is necessary for the body to produce vitamin D and support overall wellbeing, excessive UV exposure is a well-established cause of skin damage and skin cancer.

## What are UV levels?

UV levels are typically measured using the UV Index, a scale developed by the World Health Organization (WHO) to indicate the intensity of solar UV radiation at the Earth's surface. The index runs from 0 (minimal exposure) to 11 and above (extreme), helping people gauge how much protection they need on any given day. At higher values — generally above 3 — sun protection becomes advisable.

The intensity of UV radiation varies depending on several factors: time of day, season, altitude, cloud cover, and proximity to the equator. UV levels are generally highest between 10 a.m. and 4 p.m., during summer months, and at high altitudes or in tropical regions.

## How to protect yourself

Health experts recommend a combination of protective measures to reduce UV exposure. These include wearing broad-spectrum sunscreen with an SPF of at least 30, seeking shade during peak UV hours, wearing protective clothing such as long sleeves and wide-brimmed hats, and using UV-blocking sunglasses. Reapplying sunscreen every two hours — or after swimming or sweating — is also strongly advised.

While a small amount of UV exposure helps the body synthesise vitamin D, prolonged unprotected time in the sun significantly increases the risk of sunburn, premature skin ageing, and melanoma, one of the most dangerous forms of skin cancer. Checking the daily UV Index forecast and planning outdoor activities accordingly can make a meaningful difference in long-term skin health.