Relationship between mercury in kidney, blood, and urine in environmentally exposed individuals, and implications for biomonitoring

Toxicol Appl Pharmacol. 2017 Apr 1:320:17-25. doi: 10.1016/j.taap.2017.02.007. Epub 2017 Feb 9.

Abstract

Background: Individuals without occupational exposure are exposed to mercury (Hg) from diet and dental amalgam. The kidney is a critical organ, but there is limited information regarding the relationship between Hg in kidney (K-Hg), urine (U-Hg), blood (B-Hg), and plasma (P-Hg).

Objectives: The aim was to determine the relationship between K-Hg, U-Hg, B-Hg, and P-Hg among environmentally exposed individuals, estimate the biological half-time of K-Hg, and provide information useful for biomonitoring of Hg.

Methods: Kidney cortex biopsies and urine and blood samples were collected from 109 living kidney donors. Total Hg concentrations were determined and the relationships between K-Hg, U-Hg, P-Hg, and B-Hg were investigated in regression models. The half-time of K-Hg was estimated from the elimination constant.

Results: There were strong associations between K-Hg and all measures of U-Hg and P-Hg (rp=0.65-0.84, p<0.001), while the association with B-Hg was weaker (rp=0.29, p=0.002). Mean ratios between K-Hg (in μg/g) and U-Hg/24h (in μg) and B-Hg (in μg/L) were 0.22 and 0.19 respectively. Estimates of the biological half-time varied between 30 and 92days, with significantly slower elimination in women. Adjusting overnight urine samples for dilution using urinary creatinine resulted in less bias in relation to K-Hg or U-Hg/24h, compared with other adjustment techniques.

Conclusions: The relationship between K-Hg and U-Hg is approximately linear. K-Hg can be estimated using U-Hg and gender. Women have longer half-time of Hg in kidney compared to men. Adjusting overnight urine samples for creatinine concentration resulted in less bias.

Keywords: Biomonitoring; Blood; Kidney; Mercury; Plasma; Urine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers / analysis
  • Biomarkers / blood
  • Biomarkers / chemistry
  • Biomarkers / urine
  • Dental Amalgam / adverse effects
  • Environmental Exposure / adverse effects*
  • Environmental Monitoring / methods*
  • Female
  • Humans
  • Kidney Cortex / chemistry
  • Kidney Cortex / drug effects
  • Kidney Cortex / metabolism*
  • Linear Models
  • Male
  • Mercury / analysis
  • Mercury / blood*
  • Mercury / toxicity
  • Mercury / urine*
  • Middle Aged
  • Occupational Exposure / adverse effects
  • Tissue Donors
  • Young Adult

Substances

  • Biomarkers
  • Dental Amalgam
  • Mercury