CONTENTS

Introduction
Human Skin Cancer
Sunscreen and Fabric
The Mouse Model of Cancer
Studies Using Skin Tissue
Drugs and Sunlight
Plant and Algae Growth
Conclusion
Glossary
Bibliography

Fabric Protection Factors

Just as sunscreens normally have a number associated with them, a sun protection factor, so the varying protection of different types of fabrics could be expressed by a similar number, a fabric protection factor (FPF). Protection factors for sunscreens are pretty well known and tested and characterised, but no such scale exists for fabrics.

The aim of the research being undertaken by Paul Walker and Phil Lukins in the School of Physics, Scott Menzies from the Dept of Veterinary Pathology, Gavin Greenoak and Jules Martin, and Michael Pailthorpe at the Department of Textile Technology at the University of NSW, is to characterise fabrics the same way as sunscreens to give some indication of the varying way that different fabrics give protection against UV radiation. In this way garments could be labelled with protection factors and special materials could be developed which are light and cool and yet which have a high protection factor.

The impetus for this project came from Kate Georgouras who is the Director of the Lidcombe Hospital Dermatology Centre. She is connected with the University of Sydney and is a member of the University Senate. She has patients coming in with high sensitivity to sunlight exposure and has for some years been recommending they wear long sleeved shirts for protection from the sun. She wanted a more scientific basis for her recommendations so she could tell her patients which fabrics offered better protection. Dr Georgouras then approached Gavin Greenoak who put the team together and wrote a successful grant application to the Leo and Jenny Leukemia and Cancer Foundation.

The motivation for Walker and Lukins who are physicists to be involved in this project was firstly that it was something that seemed to be of public relevance. “Secondly there was a professional need for our contributions as physicists. It was pretty clear in the biological sciences that the services of physicists were sorely lacking and so there was an opportunity for interaction to produce some results which, within either field by itself, probably wouldn't occur and that was the initial motivation.”

Fabrics can have protection factors from 1 to infinity. Leather won't allow anything through that is measurable. Jeans would have a very high FPF, greater than 100. More generally the ranges found are 4-40.

People who work outside are the most important group of people who are likely to get sunburnt through fabrics, also people who work inside for a lot of the time and then spend a concentrated period outside in the middle of the day. Time of day is important because of the UV intensity and also a person's history. If someone works inside all day the shock of high exposure even for a short time can be a lot more significant than the same amount of exposure for someone who may be more accustomed to it.

There are basically two or three types of skin cancers that people may get. The one that every one knows about is melanoma and the other one is the non-melanoma skin cancers which are more common - basal cell carcinomas and squamous cell carcinomas. “It is certainly true that non-melanoma carcinomas depend on how much UV radiation you are exposed to over a period of time. So a road worker will get more even though its prolonged exposure than an office worker who goes out and gets a burst of UV. The melanoma doesn't work that way in fact it is quite the opposite, the road know that machines that detect redness aren't as accurate as humans, in the opinions of the humans. So a machine may say something is not red when the eye will tell you that it is red. So in that respect human examination is the most sensitive method but there would be some user error.”