I would be more worried about breathing the air in general or even just getting to a car, let alone eating fast food...
Lead from the boiler... Minimal even if it made into the top 1000 risks in the home.
As usual the devil is in the detail and most warnings are just that. A method of complying with regs that were implemented to fix one problem and then get carried over to other products; without due diligence. It is often a knee jerk reaction and an attempt to tick every box on ever reg to try to keep auditors and litigation at bay
If ya worried about the lead... Google the MSDS for every item that might come in contact with your skin, the water and might be given off into the air due to heat ie. the plastic of the control box and all the electronics....
After that, you will stop using google as you will be afraid to use your PC and just want a simple coffee

As it will be the safest option...
Every thing in life has a risk, from a quality perspective; only count the items that truly matter and don't get caught up in the white noise.
PS. Plenty of risks re SS and the impact that chlorine and other additives can cause when heated....
Ability is nothing without opportunity. - Napoleon Bonaparte