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Quality control in integrated human exposure monitoring of lead and cadmium

Qualitätskontrolle bei der integrierten Überwachung der menschlichen Belastung mit Blei und Cadmium

  • Quality Assurance, Interlaboratory Comparisons
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Summary

The Human Exposure Assessment Location, HEAL, Project is implemented by WHO/UNEP in close collaboration with national agencies in different countries. In a first phase methods for exposure monitoring of Pb, Cd, DDT, HCB and NO2 will be tested in China, Japan, Sweden, USA and Yugoslavia, possibly also Brazil and India. The Pb/Cd study, which involves measurements of lead and cadmium in blood, duplicate diets, feces and inhaled air, collected by a group of non-smoking women in each participating country, is coordinated by a Technical Coordinating Centre (TCC) in Sweden. In order to assure accuracy and comparability of data an extensive quality assurance programme has been developed. Quality control (QC) samples for lead and cadmium in blood, feces, air filters, dust and diets have been prepared. Sets of 4–6 External Quality Control (EQC) samples, the metal concentrations of which are unknown to the laboratories, and 1–2 Internal Quality Control (IQC) samples with stated Pb/Cd-levels, have been distributed. The analytical performance evaluation is based on linear regression analysis of reported results (y) versus reference values (x). Criteria for how much the regression line may deviate (Maximum Accepted Deviation, MAD) from the ideal line (y=x) have been developed. A power of 90% is employed, which means that the actual acceptance interval for the regression line is slightly narrower than the MAD-interval. This procedure gives an estimate of the maximum systematic errors involved in the analysis. The MAD criteria for the evaluation of QC results are based on the data quality requirements as well as the feasibility of the analytical techniques.

The results of the first QC rounds show that good analytical performance on one QC sample is no guarantee for good results at higher or lower concentrations or good results with other types of samples. Furthermore, analytical performance may vary with time.

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References

  1. Clarkson TW, Friberg L, Nordberg G, Sager PR (1988) Biological monitoring of toxic metals. Plenum Press, New York

    Google Scholar 

  2. Friberg L, Kjellström T, Nordberg F (1986) Cadmium. In: Friberg L, Nordberg G, Vouk V (eds) Handbook on the toxicology of metals, vol II. Elsevier, Amsterdam

    Google Scholar 

  3. Friberg L (1988) Quality assurance. In: Clarkson TW, Friberg L, Nordberg G, Sager PR (eds) Biological monitoring of toxic metals. Plenum Press, New York

    Google Scholar 

  4. Jorhem L, Slorach S (1988) The design and use of quality control samples in a collaborative study of trace metals in daily diets. Poster presented at the 3rd International Symposium on Biological Reference Materials, Bayreuth, May 4–7, 1988

  5. Lind B, Vahter M, Rahnster B, Björs U (1988) Quality control samples for the determination of lead and cadmium in blood, feces, air filters and dust. Poster presented at the 3rd International Symposium on Biological Reference Materials, Bayreuth, May 4–7, 1988

  6. Rosen JF (1985) Metabolic and cellular effects of lead: a guide to low level lead toxicity in children. In: Mahaffey K (ed) Dietary and environmental lead: human health effects. Topics in environmental health, vol 7. Elsevier, Amsterdam

    Google Scholar 

  7. UNEP/WHO (1984) Principles and procedures for quality assurance in environmental pollution exposure monitoring. EFP/HEAL/84.4, World Health Organization, Geneva

    Google Scholar 

  8. UNEP/WHO (1985) Report of a consultation on the human exposure assessment location (HEAL) project in Geneva, 29 April – 3 May 1985. EFP/HEAL/85.6, World Health Organization, Geneva

    Google Scholar 

  9. UNEP/WHO (1986) Report of a consultation on the human exposure assessment location (HEAL) project in Geneva, 20– 21 May 1986. PEP/HEAL/86.1, World Health Organization, Geneva

    Google Scholar 

  10. Vahter M (1982) Assessment of human exposure to lead and cadmium through biological monitoring. Report prepared for UNEP/WHO by National Swedish Institute of Environmental Medicine and Department of Environmental Health, Karolinska Institute, Stockholm

    Google Scholar 

  11. Vahter M, Slorach S (1986) Protocol for exposure and environmental monitoring for cadmium and lead. UNEP/WHO GEMS HEAL Project, National Swedish Institute of Environmental Medicine, Stockholm, Sweden

    Google Scholar 

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Vahter, M., Friberg, L. Quality control in integrated human exposure monitoring of lead and cadmium. Z. Anal. Chem. 332, 726–731 (1988). https://doi.org/10.1007/BF00472679

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  • DOI: https://doi.org/10.1007/BF00472679

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