may contain radiation in them
I'm sorry; being a scientist, this is too painful to read xD .
First of all; radiation isn't something that something else can "contain". It's like saying you can be contaminated by radiation; total bollocks. What we're talking about is something that can EMIT radiation.
Radiation happens when the nucleus of an atom becomes unstable, and it starts to emit radiation as a result of energy loss due to atomic decay. This energy can start a cascade of nucleus instability in elements that were previously not radioactive (ie. induced radioactivity). This is why the metal used in nuclear reactors, while not part of the nuclear reaction itself, become radioactive. While low level radiation wont lead to a significant amount of induced radiation, it is possible.
People can also become contaminated through exposure to radioactive elements. For example, radioactive iodine is sequestered in the thyroid and can cause damage or destruction to the thyroid gland. You can also spread radioactivity by getting something that is radioactive on your skin. This is why scientists use Geiger counters when working with radioactive substances to ensure that they have not contaminated their skin or work environment. I think you could understand the danger behind becoming contaminated by radiation through nuclear fallout as well. It isnt bullocks: people do get contaminated.
While not specifically "containing" radiation, radioactive elements do in fact contain an unstable nucleus that emits radiation. It isnt the proper nomenclature, but I wouldn't get too hung up about it.
Second; there is no appreciable amount of nuclear (as that's the kind we're talking about) radiation emitted from any household object, including your keyboard. Unless you go to Chernobyl and pick up one from the power station you're perfectly safe.
I wouldnt worry about it either.
Third; I think you're grossly overestimating the power of radiation. There are three main types of nuclear radiation; alpha, beta, and gamma. Alpha is helium cores, which are quite dangerous but so dense that even air stops it dead in its tracks after just a few centimetres. Beta radiation consists of electrons have slightly longer range, about 30 cm, but can be stopped by thick paper and isn't as harmful. Gamma radiation is probably the most well-known one because it has actual range; great range in fact. However. It has this range because it passes straight through you; for the most part, they do nothing at all.
Passing through cells without doing damage is only the good case scenario. DNA damage in varying severity can happen due to exposure to ionizing radiation. I wont go into specifics, but some of these are repaired with more efficacy than others. Some are repaired correctly without incident, some are repaired incorrectly without incident, some are repaired incorrectly to the point where the cell initiates apoptosis (cell death), and others can induce dangerous mutations in oncogenes that can cause cancer. Even small amounts of gamma radiation can result in DNA mutations and chromosomal abnormalities. "Safe" doses arent exactly immune to this danger, but DNA is self repairing so more often than not you will be ok. The danger of an improper DNA base substitution by DNA polymerase is always a possibility, however.
I wouldn't worry about any of this type of stuff with everyday materials though, as the levels are far too low to be very significant.
