Good news -- radio waves that are emitted by smart meters, cell towers, cell phones, and wifi are easily reflected by metal -- a metal screen, a piece of aluminum foil, a metal baking dish -- it does not take much metal. The closer you put it to the source of the electromagnetic field, the more effective it will be at preventing the electrical pollution from entering your home. If your smart meter is outdoors, a piece of aluminum foil, at least as large as the meter, (twice as large is better because the signal spreads in all directions as it leaves the source), placed behind the meter cuts the signal by roughly 90%. The aluminum foil can be taped to the backside of a piece of art. For indoor meters, you can place the foil over the plastic face of the meter.
Another approach is wearing clothing that contains metal. This will not prevent the pollution of your house, but it will protect your body when and where the clothing is worn. Several items are available on the website www.lessemf.com. A metal-containing hat would help with problems that involve the brain (tinnitus, headaches, dizziness, sleep problems, and perhaps heart palpitations). Heart problems can also be caused by transmissions directly to the heart, so a vest or shirt might do the trick of a hat does not.
The younger the person, the greater the dangers. Pregnant mothers should avoid using cell phones and being near things like routers and cell towers. Easier said than done. It is getting harder and harder to avoid cell towers as they proliferate like trees in a forest and are often disguised, for example, in trees, or hidden, for example, indoors in steeples or attics.
There has been a public-spirited movement for sharing neighborhood wifi. While this does reduce internet costs for cooperating neighbors, the person who houses the router is exposed to a much stronger signal than their neighbors and the signal is also stronger than that of a standard router.