P2 - Section A

UV radiation stands for Ultraviolet radiation.

Ultraviolet radiation is sunlight can cause caner. Skin cancer can kill you.

A brown pigment found in the skin called Melanin provides some protection from UV radiation.

People with ancestors that lived in sunnier parts of the world are more like to have protective brown skin, as they are more likely to have more Melanin in their body than someone who lives somewhere which is cold. 

Example: Australia (Hot) 

               Iceland (Cold)

EM stands for Electromagnetic.

The Electromagnetic spectrum has 7 stages to it. They are

radio    microwave    infrared    visible    ultraviolet*    X-rays    gamma rays

A way to remember the EM spectrum is: 

Rich Men Invent Very Unusual X-iting Gifts 

Radio has the longest wavelength and the lowest frequency / energy. Gamma rays have the shortest wavelength and the highest frequency / energy.

* Also known as UV

Why do we need the sun? 

• Human skin absorbs sunlight to make vitamin D.
• Vitamin D strengthens bones and muscles. 
• Vitamin D boosts our immune system, which protects you from infections.
• Vitamin D can also prevent the growth and spread of cancers in the breast, colon, ovary and other organs. 

Darker skin makes it harder for the body to make vitamin D.

In regions of the world that are not so sunny there is an advantage in having fair skin.

People who have dark skin can keep healthy in less sunny countries, if they get enough vitamin D from their food.

Balancing risks and benefits 

People like sunshine. This is because it can alter you mood chemically and reduce the risk of depression. 

There is no simple answer whether the sun is good for you or not. 

Over a lifetime the risk of developing one type of skin cancer such as malignant melanoma is very small. 

The chance of a UK male getting malignant melanoma is 1 in 91. 

The chance of a UK female getting malignant melanoma is 1 in 77. 

Benefits of sunbathing: Makes vitamin D, gives a tan, enjoyable and improved mood.

Risks of sunbathing: Cancer and sunburn