Reflection on “Invisible Armour: The Power of Sunscreen”

By Lui To Thomas, Po Leung Kuk Choi Kai Yau School

I have learnt a lot more about the power of sunscreen after attending the lecture, and I realised that there are a few common misconceptions by us due to our incomplete knowledge of sunscreen. One example is about purchasing a suitable brand. As consumers, we would always opt for the brand with the highest protective ability by looking at the labelling and statistics shown on the sunscreen. Our misconception is that the higher the value showed the better it is. However, I understood that the SPF scale is not linear, and a SPF value > 15 implies that the sun’s UV light protection is negligible. Therefore, it is unnecessary to purchase a brand with a SPF value that is exceptionally high because it will be much more expensive but its function remains the same.

Moreover, I understood the reason to apply sunscreen before sun exposure. It is not because sunscreen requires time to be effective. It is to ensure the sunscreen binds well to our skin to resist rub-off and wash-off by water or sweat. As sunscreen may be easily washed off, reapplying is necessary every 2 hours. Another reason for reapplying is because the chemicals in sunscreen may not be photostable, its absorbance value of UV light will deteriorate over time, therefore, making it ineffective after a long time.

Furthermore, I did some internet research on the risk of skin cancer worldwide. In the lecture, I have learnt that the darker the skin colour, the higher levels of epidermal melanin, which increase the risk of suntan but decreases the risk of sunburn and skin cancer. Australia is a country with the highest skin cancer rate which can be explained by the following. Australia is located in the equatorial region therefore sun intensity is high throughout the year. Most Australians have a pinko-grey skin colour, which is light in colour because they have Anglo-Saxon or Northern European ancestry. This suggests that their epidermal melanin level is low and the risk of sunburn and skin cancer is much higher. I am aware that sun protection is much more important when visiting these areas with strong sun intensity and I should not only rely on sunscreen. However, sunscreen should not only be applied during summer. Instead, it should be applied all year which is a huge misconception by many of us nowadays.