dangers of radiation from the sun

[johnwalton]

Hi Guys I came across an article some time ago that said there was no radiation just heat that comes from the sun what gives

[Marvin]

I am not sure how someone could say that... if you just think about it, visible light comes from the sun, ultraviolet light comes from the sun (that cause that nasty “sun-burn”) as well as infrared radiation (heat), which are all forms of electromagnetic radiation… the sun also emits electrons (beta radiation), protons (alpha radiation), plasma and charged particles (ions) including elements as heavy as iron. Luckily, the Earth’s atmosphere and magnetic field protect us from most of the harmful radiation (but from all of the radiation).

[Doc]

From Wikipedia (so not the final answer, just a starting place):

http://en.wikipedia.org/wiki/Sunlight

The spectrum of electromagnetic radiation (http://en.wikipedia.org/wiki/Electromagnetic_radiation) striking the Earth's atmosphere (http://en.wikipedia.org/wiki/Earth%27s_atmosphere) spans a range of 100 nm (http://en.wikipedia.org/wiki/Nanometer) to about 1 mm (http://en.wikipedia.org/wiki/Millimeter). This can be divided into five regions in increasing order of wavelengths (http://en.wikipedia.org/wiki/Wavelength):[5] (http://en.wikipedia.org/wiki/Sunlight#cite_note-4)


Ultraviolet C or (UVC) range, which spans a range of 100 to 280 nm. The term ultraviolet refers to the fact that the radiation is at higher frequency than violet light (and, hence also invisible to the human eye (http://en.wikipedia.org/wiki/Human_eye)). Owing to absorption by the atmosphere very little reaches the Earth's surface (Lithosphere (http://en.wikipedia.org/wiki/Lithosphere)). This spectrum of radiation has germicidal (http://en.wiktionary.org/wiki/germicidal) properties, and is used in germicidal lamps (http://en.wikipedia.org/wiki/Germicidal_lamp).
Ultraviolet B or (UVB) range spans 280 to 315 nm. It is also greatly absorbed by the atmosphere, and along with UVC is responsible for the photochemical reaction (http://en.wikipedia.org/wiki/Photochemical_reaction) leading to the production of the ozone layer (http://en.wikipedia.org/wiki/Ozone_layer).
Ultraviolet A or (UVA) spans 315 to 400 nm. It has been traditionally held as less damaging to the DNA (http://en.wikipedia.org/wiki/DNA), and hence used in tanning (http://en.wikipedia.org/wiki/Sun_tanning) and PUVA (http://en.wikipedia.org/wiki/PUVA) therapy for psoriasis (http://en.wikipedia.org/wiki/Psoriasis).
Visible range or light (http://en.wikipedia.org/wiki/Light) spans 380 to 780 nm. As the name suggests, it is this range that is visible to the naked eye.
Infrared (http://en.wikipedia.org/wiki/Infrared) range that spans 700 nm to 106 nm (1 mm (http://en.wikipedia.org/wiki/Millimeter)). It is responsible for an important part of the electromagnetic radiation that reaches the Earth. It is also divided into three types on the basis of wavelength:

Infrared-A: 700 nm to 1,400 nm
Infrared-B: 1,400 nm to 3,000 nm
Infrared-C: 3,000 nm to 1 mm

[norenrad]

I even got sun burned a few times when I was younger on cloudy days, so radiation had to have penetrated the clouds.