A critical review on normal concentrations of vanadium in human blood, serum, and urine.

An evaluation of published values for 'normal' concentrations of vanadium levels in human blood, serum, and urine have been determined in order to identify the reasons for existing large variations of these values. The published data were scrutinized according to criteria on sampling and analysis developed for the TRACY (EUREKA; ENVIRON1) project which aims at establishing reference values for persons without occupational exposure to metals. Of the sampling factors, living in environmentally polluted areas, contamination-free sampling and sample handling were found to be highly important. Expert experience is needed for the accurate vanadium determination in these fluids using well defined radiochemical neutron activation analysis (RNAA) or NAA with pre-irradiation separation or graphite furnace atomic absorption spectrometry (GF-AAS). RNAA is superior for this purpose. Lack of suitable reference materials is a severe handicap in assessing accuracy of vanadium determinations at low levels. Although no reference values for vanadium are established, it appears that values, around 1 nmol l-1 for blood and serum and around 10 nmol l-1 or slightly lower for urine may be considered tentative normal values.