As much as 80 per cent of our lifetime exposure to the sun occurs during childhood so it is vital that parents to make sure children are properly protected

Sun exposure and protection is a complex and contradictory area of child health. On the one hand, fresh air and sun are vital for the development of a child.

Sunlight, for example, is an important source of bone-building vitamin D. On the other hand, too much sun in childhood can seriously increase the risk of skin cancer in later life.

With this in mind, it is worrying that recent research published in the British Medical Journal shows that many parents still don't use sunscreens regularly to protect their kids.

There are also suggestions that adults and children who do use sunscreens may actually be at increased risk of developing skin cancer as they mistakenly believe applying it once will give them free rein to stay out in the sun for long periods.

So what is a parent to do?

If you've seen your child suffering the agony of severe sunburn, you certainly won't be blasé about protecting their skin in the future.

Skin cancer, like all cancers, is a slow developing disease, often with decades between the trigger (in this case overexposure to the sun) and the emergence of the symptoms. Research shows that six episodes of serious sunburn before the age of 18 doubles the risk of developing skin cancer as an adult.

On balance, despite the concerns raised above, if your child is going to be out in the sun for extended periods then suncream is essential.

There are two basic types of sun protection available:

• Chemical sunblocks, which reflect or scatter the sun's rays
• Chemical sunscreens, which absorb ultraviolet light (UV)

The strength of any sunscreen is measured by its sun protection factor (SPF). The higher the SPF, the greater the protection, so an SPF 15 cream provides 15 times your skin's natural protection.

Go for a minimum SPF 15

For younger children consider higher factors such as SPF 30. Use suncreams liberally and often. Try to apply the cream half an hour before going outside to give it a chance to soak in.

The sun produces three types of UV radiation: A, B and C

The SPF factor in your sun cream is for UVB protection only.

• Most UVB rays are filtered out by the ozone layer. The rest stimulate the skin to produce melanin, our natural defence against UV. For most people, however, the body can't produce enough melanin if exposed to the sun for a long time, hence the need for protection.
• UVC is completely absorbed by the atmosphere before it reaches the earth.
• UVA rays are not filtered out by the ozone layer. They penetrate the skin at a deeper level than UVB, causing greater damage.

Gauging UVA protection is difficult, though most brands now put UVA information on their labels. Look for the star rating on the back of the bottle. It will be graded from one to four stars - four stars offers the best protection.

Other factors to consider

• Many surfaces will reflect UV radiation - sand can reflect up to 25 per cent and water can reflect up to 10 per cent, depending on the time of day. If you're on the top of a mountain or down at sea level the effects of UV are intensified.
• Beware of staying in the water too long on hot summer days. You feel cooler, the water amplifies the sun's rays and washes your cream off (whatever it says on the packet) - a dangerous triple whammy.
• Up to 80 per cent of UV rays can penetrate cloud covering. Infrared rays, which give the feeling of warmth, are filtered more efficiently by clouds, so there's a tendency to stay outdoors longer on cloudy days increasing the risk of burning.
• Limit the time children spend in the sun between the hours of 11am and 3pm and be really careful with toddlers. Their skin is so sensitive they can burn, even in the shade.
• When your children are in the sun, cover as much of their skin as possible. Consider investing in special sun-protective clothing which stops UV rays from reaching the skin. Buy hats and sunglasses (look for European Standard BS:EN:1836:1997) and encourage your children to wear them.
• Use a special protective tent or umbrella on the beach so that kids have somewhere to sit out of the sun. These can be purchased in many department stores and children's shops.

Instead of scaring your kids with facts and figures about skin cancer, lead by example. Cover up and keep slopping the cream on. Then they'll follow suit.