Sun bed research shows limited reward for the risk of UV radiation exposure

New research by NIWA into the risks and health benefits of UV radiation has given scientists a better understanding of the health risks and possible benefits of sun beds.

The research is part of an ongoing study to determine the relationship between vitamin D in the blood and past personal exposure to UV radiation from various sources including sunlight and sun beds.

The study will identify seasons and regions where various subsets of the population are at risk, and what steps should be taken to reduce that risk.

Preliminary results from the study were presented at the NIWA UV Workshop in Queenstown last week.

Five hundred participants from around the country, with different skin types, age, and gender are taking part in the study.

Approximately 300 of those participants were exposed to radiation from various sun beds, where detailed measurements of the spectrum (wavelength) of radiation from the beds had been made. The purpose of that part of the study was to learn more about which wavelengths are most effective in producing vitamin D.

Measuring the UV radiation of sun beds is a complex task. There can be huge variabilities in the UV intensity between different positions in the bed. To understand the health implications, scientists also need to accurately measure the spectrum (wavelength) of radiation.

Vitamin D is crucial in skeletal development, immune function, and blood cell formation. It has recently been implicated in a wide range of diseases including cancer and heart disease. UV radiation from solarium sun beds is also used under medical supervision to treat diseases such as psoriasis and eczema.

In the New Zealand summer the UV Index can exceed 12 (well into the “extreme” category which begins at UVI=10), but in mid-winter in the south, peak UVI values are much smaller (UVI=1).

Results showed the average UVI for the sun beds commonly used in New Zealand was similar to New Zealand summer sunlight. But the same exposure in a sun bed will make less vitamin D than natural sunlight, based on knowledge of the wavelengths that produce vitamin D and sunburn.

Dr Richard McKenzie, Principal Scientist, Atmospheric Radiation, NIWA, says “more disturbingly, the intensity of radiation at some wavelengths from these sunbeds was several times higher than ever occurs in sunlight at the earth’s surface.”

“By using these sunbeds, we expose ourselves to unknown risks. Our skins may not be able to cope well with this sort of stress.”

This is normally done with a spectrometer or spectrograph, which must be calibrated against agreed-upon reference standards. Specialist equipment and procedures are needed. If sun beds become subject to regulation in the future, accurate spectral characterisations will be needed.

The research is part of a collaborative study between NIWA, the University of Otago, and the University of Auckland. It is funded by the Health Research Council.

Final results will be passed on to health professionals and policy advisors.

2010 UV Workshop

Leading researchers from New Zealand and Australia who have an interest in UV radiation and its health impacts attended a workshop, convened by NIWA, last week from 7–9 April, in Queenstown.

For more information go to: /our-services/online-services/uv-and-ozone/workshops/2010

For more information about NIWA’s UV and ozone research (including daily predictions and measurements of UV levels around New Zealand go to: /our-services/online-services/uv-and-ozone