Blood Lead, Cadmium and Zinc Correlations in Elderly Rural Residents

Open access


Background: Combined exposure to heavy metals could be expected among residents of two villages in Stara Zagora Municipality due to significant pollution sources in the region, confirmed by increased heavy metal concentrations in plant samples identified by previous studies. The risk is increased for retired villagers who consume food produced in their own farms.

Aims: To determine blood levels of lead, cadmium and zinc and the correlation between them in high-risk elderly rural inhabitants in comparison with a control group.

Materials and methods: Lead, cadmium and zinc concentrations in whole venous blood were measured by atomic absorption spectrometry in exposed and in control groups adjusted by sex, age, smoking habit, lifestyle and duration of residence in the settlements.

Results: Blood values of lead and cadmium in the exposed group were significantly higher than these in the control group (p<0.001). A statistically significant positive correlation between lead and cadmium blood levels was estimated for the exposed group (ρ=0.39, p=0.023). Blood zinc levels correlated negatively with both lead (ρ=-0.41, p=0.015) and cadmium blood levels (ρ=-0.44, p=0.009). No correlations between the studied metals were found in the control group.

Conclusion: The observed results could be explained by a long-term combined exposure to lead and cadmium in the studied elderly residents. The negative correlation of zinc blood levels versus lead and cadmium could be result of competition. Complete protein intake and supplementation with zinc, calcium and iron after control measurements are advisable for elderly rural inhabitants to reduce the health risk from heavy metal exposure.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • 1. World Health Organization. Health risks of heavy metals from long-range transboundary air pollution. Copenhagen: WHO; 2007.

  • 2. Jaishankar M Tseten T Anbalagan N et al. Toxicity mechanism and health effects of some heavy metals. Interdiscip Toxicol 2014;7(2):60-72.

  • 3. World Health Organization. Air Quality Guidelines for Europe. 2nd ed. Copenhagen: WHO; 2000.

  • 4. Järup L. Hazards of heavy metal contamination. Br Med Bull 2003:68:167-82.

  • 5. De Winter-Sorkina R Bakker MI van Donkersgoed G et al. Dietary intake of heavy metals (cadmium lead and mercury) by the Dutch population. Bilthoven: RIVM; 2003.

  • 6. Pizzol M Thomsen M Andersen MS. Long-term human exposure to lead from different media and intake pathways. Sci Total Environ 2010;408(22):5478-88.

  • 7. World Health Organization. Trace elements in human nutrition and health. Geneva: WHO; 1996.

  • 8. George PM Walmsley TA. Handbook of Trace Metal Analyses for Health. 4th ed. New Zealand: Canterbury Health Laboratories Christchurch; 1998.

  • 9. Roney N Colman J. Interaction profile for: lead manganese zinc and copper. Atlanta U.S: Department of Health and Human Services Public Health Service Agency for Toxic Substances and Disease Registry; 2004.

  • 10. Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union December 20 2006;L 364:5-24.

  • 11. Gradeva H Sandeva G Gidikova P et al. Heavy metals in plants soil and water from Stara Zagora region: defining locations for population exposure measurements. Trakia Journal of Sciences 2012;10(3):125-9.

  • 12. Björkman L Vahter M Pedersen NL. Both the environment and genes are important for concentrations of cadmium and lead in blood. Environ Health Perspect 2000;108(8):719-22.

  • 13. Černá M Pěváčková V Beneš B et al. Reference values for lead and cadmium in blood of Czech population. Int J Occup Med Environ Health 2001;14(2):189-92.

  • 14. Apostoli P Baj A Bavazzano P et al. Blood lead reference values: the results of an Italian polycentric study. Sci Total Enviro 2002;287(1-2):1-11.

  • 15. Bull S. HPA Compendium of Chemical Hazards – Lead. Version 2. HPA UK; 2011.

  • 16. Agency for Toxic Substances and Disease Registry. Case Studies in Environmental Medicine (CSEM) - Cadmium Toxicity. The Agency Atlanta USA; 2008.

  • 17. Bull S. HPA Compendium of Chemical Hazards – Cadmium. Version 5. HPA UK; 2011.

  • 18. ARUP Laboratories. Zinc Quantitative Whole Blood; 2016. Available from:

  • 19. Gulson BL Mahaffey KR Mizon KJ et al. Contribution of tissue lead to blood lead in adult female subjects based on stable lead isotope methods. J Lab Clin Med 1995;125(6):703-12.

  • 20. Nordberg GF Nogawa K Nordberg M. Cadmium. In: Nordberg GF Fowler BA Nordberg M editors. Handbook on the Toxicology of Metals. London: Elsevier; 2015:668-716.

  • 21. Garrido Latorre F Hernandez-Avila M Tamayo Orozco J et al. Relationship of blood and bone lead to menopause and bone mineral density among middle-age women in Mexico City. Environ Health Perspect 2003;111:631-6.

  • 22. Hernández-Avila M Smith D Meneses F et al. The influence of bone and blood lead on plasma lead levels in environmentally exposed adults. Environ Health Perspect 1998;106(8):473-7.

  • 23. Cheng Y Willett WC Schwartz J et al. Relation of nutrition to bone lead and blood lead levels in middle-aged to elderly men. Am J Epidemiol 2001;147(12):1162-74.

  • 24. King JC Turnlund JR. Human zinc requirement. In: Mills CF editor. Zinc in human biology. Berlin: Springer-Verlag; 1989:335-50.

  • 25. Ervin RB Kennedy-Stephenson J. Mineral intakes of elderly adult supplement and non-supplement users in the third national health and nutrition examination survey. J Nutr 2002;132:3422-7.

  • 26. Kies C Ip SW. Lead bioavailability to humans from diets containing constant amounts of lead: Impact of supplemental copper zinc and iron. Trace Subst Environ Health 1990;24:177-84.

  • 27. Chen C Wang X Chen D et al. Tofu consumption and blood lead levels in young Chinese adults. Am J Epidemiol 2001;153(12):1206-12.

  • 28. Chia SE Chan OY Sam CT et al. Blood cadmium levels in non-occupationally exposed adult subjects in Singapore. Sci Total Environ 1994;145(1-2):119-23.

  • 29. Khassouani CE Soulaymani R Mauras Y et al. Blood cadmium concentration in the population of the Rabat area Morocco. Clinica Chimica Acta 2000;302(1-2):155-60.

  • 30. Forte G Madeddu R Tolu P et al. Reference intervals for blood Cd and Pb in the general population of Sardinia (Italy). Int J Hyg Envir Heal 2011;214(2):102-9.

Impact Factor

CiteScore 2016: 0.55

SCImago Journal Rank (SJR) 2016: 0.210

Gesamte Zeit Letztes Jahr Letzte 30 Tage
Abstract Views 0 0 0
Full Text Views 168 168 13
PDF Downloads 110 110 6