Take a look at www.clarus.com. They make a pendant called the qlink that sheild you from the effects of EMF's. I've been wearing one for nearly a year now and they are absolutely brilliant. They cost about $180 but last a lifetime and a full moneyback guarantee if you're not satisfied after 90 days. Go onto the mercury forum and scroll down to my qlink post. There's more info on there.
Would highly recommend.