The Sun’s Rays – Health and Harm.

The Sun’s Rays: Health Benefits and Risks

Sunlight is an essential part of human health. We need some exposure to sunlight for the body to produce vitamin D, regulate healthy sleep patterns, and improve mood and wellbeing. However, too much exposure to the Sun’s ultraviolet (UV) radiation can damage the skin, accelerate skin ageing, and increase the risk of skin cancer. Understanding the benefits and risks of sun exposure can help people achieve the right balance, so they can live in better health and reduce the risk of skin issues.

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The Sun and Ultraviolet (UV) Rays

Ultraviolet light (UV) is the invisible portion of the light that comes from the Sun. It is divided into three types, UVA, UVB and UVC. UVC does not reach the Earth’s surface, so it is of no concern here. UVA and UVB rays affect our skin and body. They can be beneficial as well as harmful.

UVA Rays – These are present all year round and can penetrate deeply into the skin. They are primarily responsible for:

• Premature skin ageing
• Wrinkles
• Loss of skin elasticity
• Sunspots and pigmentation
• Increased skin cancer risk

UVA rays can also penetrate some types of glass, meaning exposure can occur while driving or sitting near windows.

UVB Rays – These are strongest during summer and around midday and affect mostly the outer layers of the skin. They are responsible for:

• Sunburn
• Blistering
• Direct DNA damage
• Vitamin D production
• Increased skin cancer risk

Both UVA and UVB rays can damage the DNA within skin cells, contributing to the development of skin cancer.

Why Sunlight Is Important

Sunlight is one of the body's natural sources of vitamin D. When UVB rays reach the skin, they trigger a process that allows the body to produce this essential vitamin. Vitamin D helps the body absorb calcium, supports healthy bones and teeth, and contributes to normal immune system function.

Sunlight can also provide several other benefits:

• Improves mood by stimulating the release of serotonin, a brain chemical associated with feelings of wellbeing.
• Helps regulate the body's circadian rhythm, which supports healthy sleep patterns.
• May help maintain healthy blood pressure through the release of compounds that relax blood vessels.
• Can improve energy levels and alertness, particularly when exposure occurs in the morning.
• Controlled exposure may assist in managing certain skin conditions such as psoriasis, eczema, and vitiligo under medical supervision.

How Much Sun Exposure Do We Need?

Generally, we only require a small amount of sun exposure to maintain healthy vitamin D levels. Around 10 to 15 minutes of sun exposure on the face, arms, and hands is fine, preferably in the early morning; exposure on the legs and stomach is also fine. Early morning sunlight helps to regulate our sleep cycle, so we sleep better later that night.

The exact amount required varies depending on factors such as:

• Skin type
• Time of year
• Geographic location
• Cloud cover
• Age
• Amount of skin exposed

People with darker skin generally require more sun exposure to produce the same amount of vitamin D as those with lighter skin. You need more exposure in winter months, and in southern locations, than you will need in summer weather and in areas near the equator.

When Is the Best Time for Sun Exposure?

Short periods of sun exposure before 10 a.m. or after 3 p.m. are generally considered safer because UV levels are lower at these times. The strongest UV radiation typically occurs between 10 a.m. and 4 p.m. During these hours, the risk of sunburn and skin damage increases significantly. Protective measures, such as sunscreen, shade, hats and sunglasses, are needed if you must be outdoors at these times. It is important to understand that these protective measures reduce the damage and risks of sun exposure, but cannot remove them entirely.

Do We Need More Sun Exposure in Winter or on Cloudy Days?

During winter, UVB radiation is weaker, particularly in southern parts of Australia. As a result, some people may require slightly longer periods of sun exposure to maintain vitamin D levels. However, many people incorrectly assume that cloudy, cold, or snowy days eliminate the risk of sun damage. UV radiation can still penetrate cloud cover, and cold temperatures do not block UV rays. In fact, reflective surfaces such as snow, water, and sand can increase UV exposure. For this reason, sun protection remains important throughout the year, not just during summer.

The Risks of Excessive Sun Exposure

While moderate sun exposure can be beneficial, excessive exposure causes cumulative damage over time.

Skin Cancer

Australia has one of the highest rates of skin cancer in the world. The three main types are:

• Basal Cell Carcinoma (BCC): The most common and usually slow-growing form.
• Squamous Cell Carcinoma (SCC): Can spread if left untreated but is often highly treatable when detected early.
• Melanoma: The most dangerous type, capable of spreading rapidly to other parts of the body.

Warning signs for melanoma can often be remembered using the ABCDE rule:

• A – Asymmetry
• B – Border irregularity
• C – Colour variation
• D – Diameter greater than 6 mm
• E – Evolution or change over time

Any new, changing, bleeding, or unusual skin lesion should be assessed by a healthcare professional.

Premature Ageing

UV radiation damages collagen and elastin fibres underneath the surface of the skin. Over time, this can cause:

• Wrinkles
• Fine lines
• Sagging skin
• Rough texture
• Sunspots

Eye Damage

Excessive UV exposure can also contribute to:

• Cataracts
• Damage to the eye surface
• Cancers affecting the eyelids

How to Enjoy the Sun Safely

Protecting the skin does not mean avoiding the outdoors altogether. Practical sun-safe habits include:

• Apply broad-spectrum SPF 30 sunscreen every day.
• Reapply the sunscreen every two hours when outdoors.
• Wear wide-brimmed hats that protect the face, ears, and neck.
• Use UV-protective sunglasses.
• Wear lightweight, long-sleeved clothing when practical.
• Seek shade during peak UV periods between 10 a.m. and 4 p.m.
• Avoid tanning beds and intentional tanning.

Finding the Right Balance for Sun Exposure

Overuse of almost anything can be dangerous; even too much water can be fatal. Sun exposure is no exception to this pattern. While a certain amount of sun exposure is essential to activate vitamin D production and support overall wellbeing, too much UV from the sun can cause short-term sunburn and long-term damage to the skin. And even moderate amounts of UV radiation every day can cause cumulative skin damage over time. The goal is not to avoid sunlight completely, but to achieve a healthy balance. We should aim for enough sun exposure to support our health while consistently taking precautions that reduce the risk of sunburn, premature ageing, and skin cancer. Furthermore, we should have regular skin checks that find and address any skin issues before they become serious.