Arsenic, cadmium, lead, and mercury in sweat: a systematic review.
Level 4 - case-series / case-control
Systematic review of primarily observational studies, case series, and case reports
PubMed 22505948 · doi:10.1155/2012/184745
What was done
A systematic review was conducted across Medline, Embase, Toxline, Biosis, AMED, reference lists, and grey literature from inception to March 22, 2011. The authors identified 122 records and included 24 studies evaluating concentrations and excretion of arsenic, cadmium, lead, and mercury in human sweat.
What was found
The abstract reports qualitative directional findings without providing numeric concentrations or effect estimates. In individuals with higher exposure or body burden, sweat concentrations generally exceeded plasma or urine concentrations, and daily dermal excretion could match or surpass urinary excretion. Dermal arsenic excretion was reported as severalfold higher in exposed individuals than in unexposed controls. Cadmium was more concentrated in sweat than in blood plasma. Sweat lead was associated with high-molecular-weight molecules and was higher with endurance compared with intensive exercise in an interventional study. Mercury levels normalized with repeated saunas in a single case report.
Why it matters
This review synthesizes available data indicating that sweating is a physiological elimination route for toxic elements, establishing a rationale for further research into therapeutic sweating protocols.
Limits
The abstract reports no numerical values, effect sizes, or confidence intervals. The included literature is limited by high variability in sweat collection methods, varied participant populations, reliance on case reports for certain elements like mercury, and an absence of adequately sized clinical trials evaluating health outcomes.
Cited by
- supports Mercury is excreted prominently through sweat.