Any toy you buy with a flow-soldered circuit board is going to have these elements present. Unless the kid disassembles it, scrapes the solder off the board and eats it, there's not a problem. I would bet that even it he did, there would be no detectible harm.

Citizens can't and shouldn't be protected by law from every miniscule danger. However, since the EPA has today determined that CO2, the gas we all expel when we breathe, "threatens the public health and welfare of the American people", there's apparently no limit to government intrusion into personal decisions. I expect a cap to be placed on "excessive breathing" before long, with a fine for those who overexert themselves [g].