Lead Belly/Fallout 3

Lead Belly is a perk in Fallout 3, Fallout: New Vegas, and Fallout 4.

Fallout 3
With the Lead Belly perk, the amount of radiation you would have taken from and irradiated water source is cut in half.

Fallout: New Vegas
The amount of radiation in all irradiated food and drink consumed is halved.

With Hardcore mode enabled and JSawyer installed, Lead Belly also removes the Strength penalty for eating raw meat.

Fallout 4
The first rank of this perk lowers the amount of radiation taken from food and drink, and the second rank lowers the amount even further. The third and final rank negates radiation from food and drink entirely.

Bugs

 * Lead Belly will cause food that removes rads to be half as effective.