Weird... I've been thinking about this as well.

I'm in my late 30s and I had some greying around my temples. It happened relatively quickly, but it's tough to say it's not 'natural' given my age.

However, over the past 4 month since I've been symptomatic (sparked I believe by a thimerosol-laced flu shot), my top hair has become noticeably grey. Friends have all made comments.

I'll be interested to see what happens when i start chelating (DMSA supposed to arrive in a few days).