# Heavy metals (Pb, Cd, Hg)

Lead, cadmium and inorganic mercury are the heavy metals most consistently associated with chronic low-level human exposure and adverse health outcomes in epidemiological research. Lead enters via ageing drinking-water infrastructure and legacy paint; cadmium accumulates through cigarette smoke, contaminated soil and certain foods; methylmercury is concentrated in large predatory fish through bioaccumulation. Mechanistically, these metals displace essential ions, inhibit enzymatic activity, generate reactive oxygen species and alter DNA methylation patterns — epigenetic effects linked to accelerated biological ageing. NHANES blood-lead studies have reported a continuous dose-response relationship between blood lead levels and all-cause and cardiovascular mortality even at concentrations previously considered safe, contributing to successive downward revisions of reference values.

## Sources

- Lanphear BP, Rauch S, Auinger P, Allen RW, Hornung RW. (2018). Low-level lead exposure and mortality in US adults: a population-based cohort study. Lancet Public Health. https://doi.org/10.1016/S2468-2667(18)30025-2

---

_Canonical: https://longevity-germany.com/en/glossary/heavy-metals · Part of Longevity Cities · Updated 2026-05-01_