These are anti electron. They get produced by loads of stuff. Alpha and beta radiation routinely produces electron and anti electron pairs when they interact with matter. You would need a allot of them to blow anything up.

Also the potential destructive power of anti matter realy depends on how much you have. You could have say an amount of anti matter equivilient to say a sulpher match head (energetically not mass for mass). Just because some anti matter does'nt mean imediate apocaylse