The card is indeed an Oyster, and they were supposed to be a big improvement on
the old cards which had to be passed through the barrier slot and took wear and
tear, sometimes not lasting the year. the new plastic cards usually stay in
your little wallet and just need pressing on the barrier or the widget on buses
(often these are out of order on buses round my way).
The plastic cards are supposed to last two years before expiring.
As regards electro-magnetic radiation (or induction? forgive my ignorance) I
have wondered about this. I may occasionally have carried the card in the same
pocket as my mobile, or left it lying near my PC.
Hey, if these things are damaging my oyster card what are they doing to ME?!!
Still wondering whether this is a widespread phenomenon, and whether any advice
has been given on safeguarding the cards?.