I'm an electronics engineer (retired) so I know a bit about radiation. These smart meters have a standard cellphone SIM card. In effect, they contain a cellphone. That's what creates all the "radiation"; nothing more. The electronics metering circuit doesn't produce very much radiation at all. So, if you're worried about your smart meter, you'd better worry about your cellphone, too.

That said, I keep my smart phone in my knee pocket except when I'm (briefly) using it.