Cellphones and portable media players do indeed produce measurable electrical and magnetic fields. But the strength of these fields will not affect ordinary heart rhythm or function, studies suggest.

• 手机和便携式多媒体播放器的确产生不小的电磁场。但大量研究显示这点电磁场的强度还没有能力干扰正常的心脏节律或功能。