I wouldn't ferment with brass. But from what I've read, an hour in the boil kettle isn't going to do much. However, there's playing it safe vs plain old risky, lead is serious stuff.
If it's the light yellow color brass, it's already either no or very small amounts of lead.
If you're still worried about it and want to play it safe (and I did, and I still have brass on my brew system) you can remove surface lead with a few house hold chemicals. Jon Palmer did a quick write up on this at http://www.howtobrew.com/appendices/appendixB.html
Basically, soak it in a 1 to 2 ratio mix of hydrogen peroxide (yes, go get a fresh bottle from the store, the one that's been sitting around for 2 years has probably released all of its oxygen and it's just now purified water) to plain old white vinegar. It should come out a pale gold/yellow. If the solution starts to color at all, change it out, you're now dissolving copper.