Heavy metal and metalloid (HM) exposure poses significant health risks, including cardiovascular disease, cancer, and renal damage. This contamination, prevalent in the Western US, involves arsenic (As), cadmium (Cd), uranium (U), and vanadium (V). Interstitial fluid (ISF) is a source of biomarkers, which can be minimally invasively collected using microneedle array (MA) technology. Our study hypothesized that MA-extracted ISF would facilitate noninvasive HM quantification. We established analytical parameters for HM detection in ISF using inductively coupled plasma-mass spectrometry (ICP-MS), defined baseline ISF HM concentrations in unexposed animal populations, and monitored HM levels in ISF under mixed exposure in animal models. Additionally, we assessed HM levels in ISF and biological fluids from three human subjects. Thirty-six Sprague-Dawley rats were divided into cohorts: low-level mixed HMs exposure (5X maximum contaminant level (MCL))
high-level single HM with low-level others (50X MCL for one HM with 5X for others)
and unexposed controls. ISF and plasma were collected weekly for 8 weeks and analyzed