Shade structures are not built effectively

Sep 14 2004

Skin cancer causes more than 1000 deaths in Australia, and costs the health care system over $700 million each year.

University of Southern Queensland PhD student and researcher for the university's Centre for Astronomy, Solar Radiation and Climate, David Turnbull, who has been researching local council shade structures used across Australia and the World since 2002, said most of the deaths could be prevented.

"Shade structures are not built effectively," Mr Turnbull said.

"Solar ultraviolet (UV) radiation plays a considerable role in the health and development of human beings, from initiating the formation of vitamin D to increasing the risk of skin cancer and sun-related eye disorders.

"As the public's understanding of the damaging effects associated with UV radiation increases, shaded environments will be sought to reduce personal UV exposure. However, a common misconception is that shade protects the human body against all UV," he said.

"UV radiation is evident on a surface in two distinct components, direct and scattered. Scattered UV radiation is present underneath shade structures due to scattering by the atmosphere and surroundings, and has been found to be at strengths of up to 84 percent of direct UV rays.

"While direct UV from the Sun is reflected or absorbed by the shade structure, my research has shown that significantly high levels of the scattered UV component is still present in the shade, especially during the months of late autumn and early spring."

Mr Turnbull's research revealed that shade structures that have trees, shrubs or buildings in close proximity generally have lower levels of UV in the shade than those having no such surrounding objects.

He said a good shade structure should: maximise protection from UV all year; have sufficient side-on protection to reduce scattered UV; have adequate thermal comfort for different weather conditions; be appropriately positioned in respect to full sun activities; and still allow for beneficial amounts of UV.

Mr Turnbull is using his research to design a number of different, effective shade structures, and will forward his recommendations to a number of groups, including Cancer and health organisations. He is due to finish his PhD in March next year and has spoken about his research at six conferences, both in Australia and internationally.

http://www.usq.edu.au