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

Significance of Ozone Depletion

Moore began doing his research some 19 years ago, long before people were concerned about the ozone layer. “Basically it began because pharmaceutical manufacturers were concerned about whether their compounds were affected by light,” he says. “This is an important question of stability. They need to know whether the products are going to break down and to assign a shelf-life or expiry date. But moving on from there one sees that this area of research does impinge on the effects of atmospheric ozone depletion because it is going to mean that more and more compounds are going to be able to carry out this sensitisation process.”

“It is important to recognise,” says Moore, “that sunlight currently does not contain wavelengths below about 290nm in the UV region because the ozone layer prevents shorter wavelengths getting through. But if the ozone layer is depleted wavelengths may go down to 280nm, or perhaps even less. So therefore it is important to look at the relationship of these drug reactions to the wavelength of light involved.”

But the main consideration is that some of these drug molecules absorb UV over a wide range of wavelengths. The normal region which causes sunburn without any other agents being involved is called the UVB region. That is the region between 290-310 nanometers. If a drug molecule is present in the system it may absorb longer or shorter wavelengths of light and thereby cause a reaction. Most of the older sunscreen agents were designed to cover that main region of 290-310 nm and they don’t afford protection against the longer wavelength absorption. That is why some of the new sunscreens are described as “broad spectrum”. They cover a wider range of wavelengths from 280 to 360 nm.

Although Moore’s research is unique in Australia there are people in Boston, the Netherlands and also a group in Norway who are working in related areas. There are different aspects of the work and different people approach it from different view points and with different skills, but basically there are probably only about 5 other groups in the world doing this sort of thing. Moore makes contact with them from time to time. On occasions he has actually had some of them visit him to work in his laboratory for a short period of time in order to study some of his techniques. Similarly he has sometimes travelled overseas to study the techniques being used in other laboratories.