Jay,
Not true. The lead oxides in paint (white lead) can be an issue as paint is available to be abraided off by touch, damage, etc (think of wiping your hand on lead paint & then eating something without washing your hands)...this assumes the surface hasn't been painted since the 70's. Lead shot in a container (speaker stand) isn't available to touch & won't be 'evaporating' anytime soon. I would load the stands with lead outside & wash up afterwards...after that..not an issue.