Lead

Lead is a toxic heavy metal that harms nerves, blood, and development, with no known safe level. Old paint, old plumbing solder, some ceramic glazes, and industrial exposure are the common sources. A pooled analysis of seven international cohort studies found an inverse, supra-linear relationship between blood lead and children's IQ with no clear threshold, estimating that as little as 0.1-1.0 mcg/dL of additional blood lead was enough to cost one IQ point.

Sources Peat flagged

Asked about lead in ceramics, Peat gave a practical visual test rather than a blanket warning:

If it doesn't have a shiny glaze, it's probably not a lead problem.

— Ray Peat

On water, he noted that hard (mineral-rich) water dissolves less lead from old plumbing than soft water does, part of why hard-water regions show better average health outcomes independent of the water itself:

Hard water doesn't dissolve as much lead from the plumbing (such as soldered connections of copper pipes).

— Ray Peat

Hair testing can pick up recent environmental lead exposure, including from gun smoke, though Peat cautioned that pharmaceutical chelation itself can mobilize stored metal and increase brain and kidney exposure during removal.

Reducing exposure

Remove known sources (old paint, suspect solder, shiny-glazed ceramics of uncertain origin). Milk, orange juice, and coffee were his general recommendation for safely supporting heavy-metal clearance; see Heavy metals for the fuller quote and context.

See also

• Heavy metals
• Mercury
• Aluminum
• Brain
• Anemia
• Harm reduction