The researchers also made the important observation that, "Biomonitoring for toxic elements through blood and/or urine testing may underestimate the total body burden of such toxicants. Sweat analysis should be considered as an additional method for monitoring bioaccumulation of toxic elements in humans."
These are truly novel findings insofar as sweating, at least from the perspective of evolutionary biology, is considered to exist primarily for thermoregulation (sweat cools the surface of the skin and reduces body temperature, functioning as a wholebody cooling system). While the sweat glands have a well-known secondary role for the excretion of water and electrolytes, this function is not generally understood to be a form 'detoxification.'
Also, this study underscores just how common it is for conventional medical practice to overlook the relevance of environmental factors in health (e.g. exposures to metals, petrochemicals, toxins), as many of these 'vectors' of exposure/poisoning are not properly measurable via blood or urine tests; that is, when they even care to look. This blind spot, of course, feeds the delusion that one can suppress bodily symptoms associated with environmental exposures with additional patented chemicals, in the downward spiral that is drug-based medicine. The obvious alternative method - identify and remove the poisons - isn't even on the table, unless the practitioner happens to be aware of natural, integrative or functional medical principles and has the courage to go against the FDA-approved and liability-shielding grain to employ them.
Why Blood and Urine Analysis May Fail To Reveal The Problem
These preliminary research findings were further confirmed in a 2012 meta-analysis published in the Journal of Public and Environmental Health. The study titled, "Arsenic, cadmium, lead, and mercury in sweat: a systematic review," was performed by researchers from the Children's Hospital of Eastern Ontario Research Institute, Ontario, Canada, and was based on a review of 24 studies on toxicant levels in the sweat.