The weather is a pretty universal topic of small talk wherever you go.
The short conversations generally revolve around the day’s temperature, how hot, how cold, whether it was predicted or out of the ordinary.
One thing that is not talked about on a hot day nearly as often as temperature is solar radiation.
The federal government’s Australian Radiation Protection and Nuclear Safety Agency does provide us with a ultra-violet radiation (UVR) index and tells us when it is at a low, moderate, high, very high, and extreme level. The UV Index was invented by Canadian scientists, introduced there in 1992 and designed to sit on a figure between one and 10.
During the Australian summer the rating often blows out well above 10 and even at the moderate rating of three we are advised to “wear sun protective clothing, a hat, sunscreen, sunglasses and seek shady areas”.
The index is a simplified way of expressing the risks of an “average” adult with lightly tanned skin developing sun burn, which is most likely at solar noon, which is halfway between sunrise and sunset, or roughly midday by our clocks.
UVR does have health benefits in moderation, such as inducing Vitamin D production, yet when a person is over-exposed it is believed to cause DNA damage, skin cancer, immunosuppression and eye damage.
Our body’s largest organ is our skin so obviously people with different levels and types of skin pigments or melanin will react differently to different levels of UVR.
Melanin is thought to protect your DNA from damage by UVR with the most common forms being eumelanin, pheomelanin and neuromelanin.
Eumelanin creates brown or black skin, pheomelanin is responsible for red hair and other pink skin pigmentation and neuromelanin is a dark pigment in your brain.
Swedish researchers in 2014 discovered that eumelanin converts the harmful UVR into heat with “almost 100 per cent efficiency” in “less that a thousandth of a billionth of a second”.
On the other hand, pheomelanin is believed to cause skin cancer, which would explain Australia’s extremely high rate of skin cancer.
Melanin is an extremely understudied part of the body and the more we understand the body’s natural defences the better we will be able to combat UVR.
Until then, remember to cover up.
