The real hazard is inhaling rosin fumes (says the guy who doesn’t properly ventilate his workstation). If you’re anxious about lead (I was) there is lead-free solder, though it requires higher temperatures to work with. As far as lead goes, the risk is from getting flecks of it on your fingertips and then touching your eyes or mouth. I imagine it’s less of a problem than it feels like in my head, but something something environmentally friendly.