I'm assuming that you're aware that lead exists in the piping and/or fixtures of your home's, your place of work's, your kid's school's water system, etc, etc. If you haven't replaced most of your home's water delivery system then you're likely "sucking on a sinker, sprinkling it on your salad or your kid's cerearl". I'd be a bit more concerned about lead that I'm directly consuming, but then I'm "stoopid" and don't see the big deal of losing tiny sinker in a massive volume of water.
As a thought experiment, 1 acre foot of water equals 325,851 gallons of water. An acre foot is the amount of water needed to cover 1 acre to a depth of 1 foot. So, a tiny 2 acre pond that averages just 5 foot in depth holds 3,258,510 gallons of water. A 1,000 acre lake that averages 10 foot in depth holds just over 3.25 billion gallons of water. Little bullet sinkers aren't going to have any effect on the dissolved lead levels of that much water.