Maybe if it were made from copper. In any event, we’ve been bombarded by RF for the last 80 years.
I’m not aware of any smart meters that transmit more than 1 watt on the 900MHz band. That’s puny. Nor am I aware of any smart meters that transmit continuous duty, generally they are polled at some interval and the more meters that exist, the slower the poll rate will be. As you can imagine, less transmitting means less RF exposure.
I’d be more worried about holding a cell phone up to my face for 20 minutes at a time. 500 milliwatts at 1/4" inch is going to radiate more power in your body than 1 watt at several tens of feet, attenuated by stucco, framing, wallboard, and whatever else is between your domicile and the meters.
In any event, to answer the OP directly, not only are RF exposure limits based on averaged exposure time, they’re also segregated between occupational exposure and general population exposure. The devices of which you speak are generally covered by the Part 15 of the FCC’s rules, and are not dissimilar to cordless phones, baby monitors and other devices that make use of the ISM band.
Perhaps I’ve missed it, have there been any causative reports of 900MHz cordless cell phones causing cancer and the like in the last 20 years? No doubt the general population has received much more RF from these devices, simply because they’ve been in existence much longer and are used in a manner which exposes the user to more RF than a smart meter does.
To be clear: TV stations have engineers that will spend 10-12 hours a day at RF dense sites (such as Mt Wilson near Los Angeles, one of those most RF dense locations in the world) and nobody is aware of any causative link between the mega amounts of RF these folks are exposed to day in and day out and any ill health effects.
If anyone is aware of such empirical data, please share it, I’m confident folks in the industry would read it with eagerness.
Don’t get me wrong-- RF exposure can be bad. Touch an element on an antenna putting out 50kW and you’re going to get burned. Put your nuts in front of a microwave transmitter and you’re probably saving on birth control for the rest of your life.