Bracelet warns of too much sun exposure

Scientists in Britain have come up with what appears a very sensible idea - a team at Strathclyde University in Scotland have developed an early warning sunburn indicator - it comes in the form of a thin strip which turns pink after too much exposure to ultra-violet light.

The scientists say overexposure to ultraviolet radiation (UVR) is a recognised health hazard and acute effects from short-term exposure include sunburn (erythema) and photo-conjunctivitis - long-term exposure can lead to chronic conditions such as photoaging, skin cancer and cataracts.

Usually UVR levels are measured based on the UV index system, where a UVI value of 6 is typical of a summer's day in the UK and most Caucasians would be likely to experience sunburn after only 28 min on a summer's day in the UK.

The strip is filled with "intelligent ink", which turns pink after too much exposure to ultra-violet light, can be worn as a bracelet or label on clothing and costs as little as 20p each to produce and can be set to suit different skin types.

Sun protection creams and lotions should be applied as normal and the strips apparently allow the sun protection factor to be taken into account.

Professor Andrew Mills, who led the team, says the strips and labels respond to UV light and change colour at a rate which depends on a person's skin type - the printable, multicomponent, UV-sensitive indicator strip provides different coloured, flag-like warnings of the approach of sunburn.

According to Professor Mills most people do not know they are showing the signs of sunburn until 4 to 8 hours after being exposed - he says the UV component of sunlight, can be deceiving and the usual signs of burning and damage are delayed and this is the major problem with sunburn.

Professor Mills says a sunburnt skin is a damaged skin and can lead to serious consequences.

The researchers say despite greater awareness amongst the general public of the potential dangers of UVR overexposure, the number of attributed cases of skin cancer continues to rise, currently over 70,000 people develop skin cancers each year in the UK, 9,000 of which are malignant, leading to 2,000 deaths.

The researchers are hoping to test a prototype this summer and say the indicator may prove a useful device for preventing sunburn and, by implication, skin cancer, but the test will be getting people to use them.

The research is published in the Royal Society of Chemistry - Journal Chemical Communication.