Ultraviolet (UV) rays are part of the sunlight. The sun is our friend. UV rays can be helpful, like when they help to make Vit D in our skins. How much UV do we need to make Vit D? The World Health Organization (WHO) recommends 5 to 15 minutes of sun exposure 2 to 3 times a week. However, too much sunlight can be dangerous. The natural UV from the sun is known to cause skin damage and wrinkling, but more importantly, UV may cause different types of skin cancer.
Types of UV
Since UV is not as high-energy, as the ionizing radiations, it does not pass the skin, so cancers of other parts due to UV have not been reported. There are three types of UV radiations based on wavelengths: UV A, UV B and UVC.
| Type of UV | Wavelength (nm) |
| UVA | 315-399 |
| UVB | 280-314 |
| UVC | 100-279 |
The ozone layer absorbs all UV C, and most of UV B. But UVA is not absorbed. What reaches our skin is 95 percent UV A and 5 percent UV B, which has escaped the ozone layer. Both UVA and UVB can cause cancer.
UV rays can cause different types of skin cancer: One type is malignant melanoma. It is a type of cancer that originates from the pigment-producing cells in the skin. Melanoma is a very malignant tumour. When people get recurring high doses of UV, like sunbathing or indoor tanning, they increase the risk of getting this cancer.
There are other types of skin cancer, like squamous cell carcinoma and basal cell carcinoma related to UV. These cancers usually develop due to long term exposure to sunlight, like when you work or stay every day, for a long time under the sun.
UV protection
What can we do to prevent UV from causing cancer? There are a couple of ways:
- if possible, Avoid direct sunshine, especially in the middle of the day.
- Do not forget sunglasses.
- Try to cover your arms and legs. Also, wear a hat to protect your face and neck from the sun.
- Use an ample amount of sunscreen. The sunscreen you need should be at least SPF 15. SPF 30 is even better. The sunscreen should protect from both UVA and UVB. Apply sunscreen 15 to 30 minutes before sun exposure, If you have to stay under the sun for a long time, repeat the sunscreen every two hours.
- Avoid indoor tanning
