Supplementary Material for Bioaccumulation of heavy metals and Metallothionein-1 response in Peromyscus leucopus inhabiting the Tar Creek Superfund Site

Environmental contamination by heavy metals is an ongoing concern, particularly in areas with a history of mining, smelting and other industrial activity. The present investigation reports findings of continued biomonitoring studies at the Tar Creek Superfund Site (TCSFS), OK, USA. Here we investigate the bioaccumulation of lead (Pb), cadmium (Cd), and zinc (Zn) and the induction of Metallothionein-1 (MT-1) in the white-footed mouse (Peromyscus leucopus) inhabiting the TCSFS and two reference sites: Oologah Wildlife Management Area (OWMA) and Sequoyah National Wildlife Refuge (SNWR). Utilizing inductively coupled plasma-mass spectroscopy (ICP-MS) and enzyme-linked immunosorbent assay (ELISA), we quantified the concentrations of these heavy metals and MT-1 in kidney specimens of P. leucopus. Our results revealed significantly higher concentrations of Pb (0.57±0.10 µg/kg) and Cd (4.62±0.71 µg/kg) in the TCSFS population compared to reference sites, while Zn levels (23.1±3.3 µg/kg) remained consistent across all locations. Interestingly, MT-1 concentrations did not significantly differ between TCSFS and reference sites, suggesting a complex interplay between heavy metal exposure and MT-1 induction. Our investigation highlights the need for further research into the mechanisms of MT-1 response and its potential as a biomarker for environmental heavy metal contamination.