Sunburn figures confuse many say researchers

By MARTIN JOHNSTON health reporter

Almost one New Zealander in two does not understand the burn time indicator and may be risking sunburn and potentially fatal skin cancer.

Researchers warn that helping people to protect themselves from the sun's harmful rays has become even more important than in the past, with a 12 per cent increase in summer peak levels of ultraviolet light in the 1990s and a rising rate of sunburn.

A telephone survey of 396 people in January 1999 showed that 89 per cent were aware of the burn-time indicator and 43 per cent knew of its alternative, the ultraviolet index.

But only 51 to 55 per cent of those aware of the indicator knew that as the "burn time" increased, so too did the time you could spend in the sun. (Don't knows were excluded.)

In contrast, people's comprehension of the UV index was much better, the researchers say.

The UV index shows the amount of ultraviolet radiation under clear skies, graded from "minimal" to "extreme," for each hour from 10 am to 3 pm.

New Zealand has one of the world's highest death rates from melanoma, the most lethal form of skin cancer. About 1600 new cases are reported each year.

"Yet melanoma is one of the most preventable cancers, with over 90 per cent attributable to sunlight exposure in Australasia," say the researchers, Jean-Luc Bulliard and Anthony Reeder, in the latest New Zealand Medical Journal.

Since New Zealanders relied more on the burn-time indicator than the UV index, misinterpreting the burn time could have worse consequences, they wrote.

The Cancer Society, which part-funded the study, said the findings were disappointing.

But spokeswoman Belinda McLean said they reinforced the society's campaign urging all television, radio and newspaper weather reports to use the UV index rather than the burn time.