How does rain or snow that's radioactive harm?

How can low level radioactive snow or rain make you ill, but NOT give you radiation sickness? This video shows an exposed ccd taken from a camera. It is similar to the exposed surface of your skin, inside your nose, mouth, throat and lungs. Alpha particles don't go very deep. When alpha particles emitted by radioactive snow or rain enter your body, the damage done to this ccd camera, is similar to the damage done to your internal tissue. Bacteria that protect you, are killed and other bad bacteria can grow rapidly in their place. The result can be a flu or cold.
Even LOW levels of alpha radiation can do this. As you will see, they are very damaging to sensitive surfaces. This makes a lot of medical professionals money, but can easily be prevented with nothing more than a filter mask. The hands and external surface of your body are not harmed, as they are mostly dead cells, and shield your tissues. All snow and rain is NOT radioactive, so don't you dare believe that. There is no reason to fear radiation, but if it is denied, it can have harmful effects when precautions are not taken. The need to prevent panic is often an excuse to endanger the public. The radiation in the snow or rain can come from many sources such as radon, tennorm, or fallout from nuclear plants and etc. The results on this ccd lens, are like the damage to the tissues inside the body, when the particles are inhaled. I assure you, looking a bit over careful, is far better than enduring the new strain of flu virus, that is ready and waiting to make your local hospital and pharmacy a boat load of money. No need to fear it, just be aware.