Cadmium, chromium, lead, manganese and nickel concentrations in blood of women in non-polluted areas in Japan, as determined by inductively coupled plasma-sector field-mass spectrometry.

backgroundBackground levels of metals of toxicological or industrial importance have been reported for several populations in the world. The information on the levels of metals of industrial, occupational or clinical importance in blood of general Japanese populations is however still scarce.

objectivesThe objectives of the study were to establish background levels of Cd, Cr, Mn, Ni and Pb in blood of Japanese population using inductively coupled plasma-sector field mass spectrometry (ICP-SF-MS), which was expected to be sensitive enough to measure low-level Pb in blood of general populations. For this purpose, women, rather than men, were studied to minimize the effect of smoking. An additional objective was to examine possible contamination from devices in phlebotomy process.

methodsBlood samples were collected in 2000's from 1,420 adult women in eight prefectures of no known anthropogenic environmental metal pollution in Japan, and the samples were subjected to ICP-SF-MS analyses after wet digestion with extra-pure nitric acid. Ultra pure water samples aspirated into blood sampling vacuum tubes were analyzed to detect possible metal contamination.

resultsContamination of blood samples from phlebotomy device was detected for Cr and possibly for Mn and Ni, whereas it was below measurable levels with regard to Cd, Ni and Pb. Under this limitation, GM metal concentrations in blood were 1.23 μg/l for Cd, 0.55 μg/l for Cr, 13.2 μg/l for Mn, 1.81 μg/l for Ni and 15.8 μg/l for Pb. Cd and Pb tended to increase in association with age, whereas Cr, Mn and Ni tended to decrease. Smoking induced elevation both in Cd and in Pb in blood. It was also made clear that the ICP-SF-MS is reliable for measurements of Cd, Mn and Pb in blood allowing evaluation even on an individual basis, while the results of Cr and Ni should be reliable on a group basis (e.g., n ≥ 5). Limitation in compatibility was discussed between the results by ICP-SF-MS and that by traditional graphite furnace atomic absorption spectrometry.

conclusionsICP-SF-MS is a reliable method of blood analysis for Cd, Mn and Pb even for the evaluation on an individual basis. Cr and Ni analyses should be reliable on a group basis, probably due to limited performance inherent to the analysis principle and matrix. Possible contamination from phlebotomy devices with Cr should be taken into account in evaluating the results.