Teenagers rewarded for scientific investigations

October 2nd, 2019, Published in Articles: EE Publishers, Articles: Energize

Are school uniforms “silent killers”? This question was studied and answered by two teenagers from Cape Town’s Rondebosch Boys’ High School recently. Research undertaken by Grade 10 learners André Toerien and Zuhayr Halday, revealed an unexpected result and went on to win them the Hendrik van der Bijl  prize, sponsored by EE Publishers, at the recent Eskom Expo for Young Scientists award ceremony held at the Birchwood Hotel and OR Tambo Conference Centre in Gauteng.

The aim of this scientific investigation was to determine to what degree different colours of school clothing block ultraviolet (UV) rays. It was hypothesised that darker colours of cloth would be more effective in preventing UV rays from reaching the skin. In the experiment, all clothing samples were a blend of 65% polyester and 35% cotton and were of the same thickness.

Zuhayr Halday and André Toerien with EE Publishers’ Roger Lilley.

Dangers of UV radiation

According to the World Health Organisation (WHO), exposure to the UV radiated by the sun damages human skin. Chronic exposure to UV radiation causes a number of degenerative changes in the cells, fibrous tissue and blood vessels of the skin. These include freckles, nevi and lentigines, which are pigmented areas of the skin, and diffuse brown pigmentation. UV radiation accelerates skin ageing, and the gradual loss of the skin’s elasticity results in wrinkles and dry, coarse skin.

The best-known acute effect of excessive UV exposure is erythema, commonly known as sunburn. In addition, most people will tan from the UV stimulation of melanin production, which occurs within a few days following exposure. A further, less obvious adaptive effect is the thickening of the outermost layers of the skin which attenuates UV penetration to the deeper layers of the skin. Both changes are a sign of damage to the skin.

Susceptibility to skin damage depends on skin type; individuals with fairer skin will be more prone to sunburn than people with darker skin. Similarly, the ability to adapt to UV exposure (the ability to tan) also depends on skin type.

Exposure to the sun’s UV radiation leads to skin cancer, usually non-malignant, but in some cases malignant which can lead to premature death. Non-malignant skin cancer, though not death-threatening, can require painful and even disfiguring surgery.

Since school children tend to spend a great deal of time outdoors while wearing prescribed school uniforms and the risk of skin cancer from being exposed to UV radiation is serious, the two teenagers decided to identify which colours and cloth types, used in school uniforms, offer the best protection from the sun’s UV radiation.

Detecting UV light

Toerien and Halday discovered a new method for detecting UV light. They found that quinine in tonic water glows pale blue in UV light. Tonic water was poured into a container and a UV torch was shone into it through a piece of fabric. To measure the intensity of the blue glow, a camera in conjunction with an image editing program was used. Values were found by measuring the intensity of the blue colour channel at a fixed distance from the container. These values were used to find the percentage of UV light which was able to pass through each of the samples.

The most UV-resistant samples allowed less UV radiation to pass through, which resulted in a lower percentage of UV radiation penetration. All three of the white samples had much higher penetration percentages than any other tested samples. Additionally, the two black samples tested had the lowest percentages in their respective clothing types.

Results

The results show that school uniform fabrics need to be reviewed to ensure they protect learners from unnecessary risks. Schools should pick darker colours for their clothing, as they are more UV-resistant and will provide better protection against the sun’s UV rays.

Eskom Expo for Young Scientists

If South Africa is to grow a technology-based industry and build a knowledge economy, it is imperative that learners in its schools are shown at an early age that science, technology, engineering and mathematics (STEM) are fun subjects leading to “cool careers”. This is precisely the aim of the annual Eskom Expo for Young Scientists, which encourages young people to become involved in science and engineering projects and compete at local, national and international level.

To stimulate the direct involvement of sponsors in expo awards and bring industry on board, Dr Stafford Smithies, consultant, VSA and Chris Yelland, MD of EE Publishers, introduced the “Hendrik van der Bijl Awards” in recognition of his contribution to science and engineering on numerous fronts. The Hendrik van de Bijl Awards are an easy way for sponsors, either individual or corporate, to become involved and invest in learners who, at a young age, show an interest in the world of science.

Send your comments to energize@ee.co.za

 

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