Part C: UV Experiments

Observing The Effects of Solar Ultraviolet Radiation on Cells

The sun is so hot that it gives off enormous quantities of ultraviolet (UV) photons. These can damage the DNA in your cells and cause skin cancer. If all of the UV photons coming towards the earth reached its surface, most plants and animals would die. However, the upper atmosphere (stratosphere) contains enough ozone to filter out most but not all of the damaging UV photons. The amount of UV that reaches the surface of the earth on a clear day can still give you a sunburn, skin cancer, or eye damage if you are exposed to it for too long. The amount of time you can safely be exposed to sunlight depends on several variables: