Normal cell phone use involves holding your phone—a radiation source—in close proximity to your head, hence the concerns about cell phone safety. Hands free kits can make cell phone use safer by enabling cell phone users to move their phones away from their heads. An alternative approach, however, is to use a radiation shield. These seek to shield the antenna of your cell phone and so reduce the proportion of radiation absorbed from it.
Radiation shields for cell phone antennas are not all effective. Though many radiation shields claim to have significant safety benefits for cell phone users, they often to so without any independent testing to verify those claims. An independent scientific journal paper tested nine different radiation shields and concluded that none of them had any effect or reduced the radiation absorption rate as they claimed. In February 2002 the Federal Trade Commission filed charges against two companies for marketing cell phone shields using unsubstantiated safety claims.
Another scientific journal investigated three other antenna shields, and found that they did have some benefits. One of those shields had only a negligible affect, but the other two did significantly reduce the proportion of radiation absorbed into the head. Both of these shields, however, impaired the performance of the cell phone antenna, reducing its operational range. Reducing the efficiency of a cell phone in this way causes it to use more power, and so emit more radiation, and so this effect negates the benefits of the shield to a certain extent. The shields also caused the phones that they were used with to heat up dramatically, potentially reducing their life-time. Some antenna radiation shields, then, may offer some benefits. Others, though, have not been proven to have any benefits at all, and may even compound the risks. Buyers should therefore take great care in selecting a cell phone radiation shield.
