Answer to Question #4359 Submitted to "Ask the Experts"

I live approximately 700 feet away from a cell tower with several antennas. How can I reduce the level of radiofrequency (RF) entering my home? Also, will screening outdoor living areas with aluminum screen reduce exposure in those areas? I know that many reports find that at a distance of 700 feet away from an emitting antenna, my family is not going to be affected by RF radiation. However, I would be more at ease by at least trying to provide some kind of protection.

You are correct that at a 700-foot distance the levels of radiofrequency (RF) radiation in the environment from a cell phone tower are minimal. In fact at that distance the RF emissions from yours or your neighbor's handheld cell phone may be more powerful than those coming from the tower.

Wire mesh or metallic screens do provide shielding from incident RF energy. You can see this in action by looking at the door to your microwave oven, most of which have a metal screen to prevent leakage of RF energy while allowing you to look inside.

You are also correct that shielding a house from cell phone emissions would not be something that an RF safety expert would recommend. It is not only unnecessary, it is also rather impractical as the screen or mesh must enclose the point to be protected. This is because RF waves reflect off nearby surfaces [this is how you get cell phone coverage, say, behind a building that stands between you and the nearby tower] so a single screened window for example might block only a very small fraction of the total RF energy in the environment.

Gary Zeman, ScD, CHP