Lead as a solid is not dangerous provided you dont knaw on it when youre bored

or for that matter sip gasoline
The only slight hazard is in the melting process but you would have to do it alot for it to be measurable like we do.
Although neat how that works, what you end up with is more of a toy than a hammer. Within just a few blows the head becomes loose and after awhile a projectile. The ridges on that pipe only holds the lead when cast but when you pound the lead slips on the ridges and loosens.
If you'd rather not invest in a mold for 80.00 and then some lead and a respirator only to end up with a little hammer that gets loose when you use it and then you have to pour it again, I have a better idea...
I am the president of American Hammer, we manufacture the very best lead hammer on the market and if you get in touch with me via the website, i'll send you a a brand new 4lb lead hammer for 25.00 and that will include the shipping to your home. Its unlikely you'll ever need a replacement because the reason a lead hammer doesnt last very long is the softness of the head and that silly pipe handle that doesnt hold on to the head for long, well we have a secret, it doesnt need to be that soft and our heads never come loose. Plus we'll recast your hammer for life at only 15.00, something your son or daughter will take advantage of.
www.americanhammer.com Take care all.