Associations and Interactions between Heavy Metals with White Blood Cell and Eosinophil Count

The accumulation of heavy metals in the body has been associated with an elevated immune response. The aim of this study was to investigate the associations among heavy metals and white blood cell (WBC) and eosinophil count in the general population in southern Taiwan. We also explored the interactions and synergetic effects of heavy metals on WBC and eosinophil count. We conducted a health survey in the general population living in southern Taiwan between June 2016 and September 2018. Seven heavy metals were measured: blood lead (Pb), and urine cadmium (Cd), copper (Cu), nickel, arsenic (As), chromium and manganese (Mn). A total of 2,447 participants were enrolled. In multivariable analysis, high concentrations of Pb (log per 1 mg/L; coefficient β, 0.332; p = 0.005) and Cu (log per 1 μg/dL; coefficient β, 0.476; p < 0.001) were significantly associated with a high WBC count. In addition, high concentrations of Pb (log per 1 mg/L; coefficient β, 0.732; p < 0.001), As (log per 1 μg/L; coefficient β, 0.133; p = 0.015), Cu (log per 1 μg/dL; coefficient β, 0.181; p = 0.018), and Cd (log per 1 μg/L; coefficient β, 0.139; p = 0.002) were significantly associated with a high eosinophil count. Further, the effect of interactions between Pb and As (coefficient β, 0.721; p = 0.029) and Mn and Cu (coefficient β, 0.482; p = 0.018) on WBC count, and As and Cu (unstandardized coefficient β, 0.558; p = 0.002) on eosinophil count were statistically significant. In conclusion, the heavy metals Pb, As, Cu, and Cd were associated with WBC and eosinophil count. In addition, synergistic effects of heavy metal poisoning on the association with WBC and eosinophil count were also observed.