Heavy Metal Pollution from Dental Clinics–Part 1:Annual Emissions Assessment

Document Type: Original Research Paper


1 Petrochemical and process engineering department, Laboratoire de Génie Chimique et Environnement de Skikda ,Postcode21000,Université20 Août 1955Skikda, Alegria

2 Laboratoire de Sécurité des Procédés Chimiques,Postcode76801, Normandie Univ, INSA Rouen Normandie, Rouen, France


This study aimed to evaluate the concentration of heavy metals in liquid effluents and to quantify the mercury content in dental amalgam waste generated by dental clinics. Three neighbouring cities in Northeast Algeria were considered in this study (Constantine, Skikda, and Annaba). Heavy metals, such as Hg, Cu, Zn, Fe, Ni, Mn, Cr, Cd, and Pb, were analysed in wastewater and then compared with acceptable standard values. Special attention was given to mercurybecause of its dangerous effects. The results collected indicated the presence of heavy metal contamination in dental wastewater. Heavy metal concentrations were significantly high for all heavy metals and exceeded the allowed concentrations. However, Pb and Cr were shown to have acceptable concentrations. This study highlights the possible contamination of the environment by mercury and heavy metals generated by dental clinics. This study also demonstrates an order of magnitude of the concentration of these heavy metal in a large agglomeration with a population of 2.5 million people.


Adedigba, M. A., Nwhator, S. O., Afon, A., Abegunde, A. A. and Bamise, C.T.(2010).Assessment of dental waste management in a Nigerian tertiary hospital. Waste Manage Res., 28(9); 769-777.
Adegbembo, A. O., Watson, P. A. and Lugowski, S. J. (2002). The weight of wastes generated by removal of dental amalgam restorations and the concentration of mercury in dental wastewater. J Can Dent Assoc.,68(9) ; 553-558.
Agence française de sécurité sanitaire des produits de santé (AFSSAPS). (2005). Le Mercure des amalgames dentaires: Actualisation des connaissances. Mise en place d’un réseau d’évaluation pluridisciplinaire, Recommandations, Paris.
Alomary, A. and Belhadj, S. (2007).Determination of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn) by ICP-OES and their speciation in Algerian Mediterranean Sea sediments after a five-stage sequential extraction procedure. Environ Monit Assess., 135(1-3); 265-280.
ASTM , American Society for Testing and Materials, Annual book of ASTM standards, ASTM International, West Conshohocken Pa, USA, 2012, http://www.astm.org/.
Bates, M. N. (2011). Dental amalgam fillings: a source of mercury exposure. Encyclopedia of Environmental Health., 11-20.
Berglund, P. and Diercks, R. (2001). Evaluation of amalgam removal equipment and dental clinic loadings to the sanitary sewer. St Paul: MCES and Minnesota Dental Association (MCES Report No. 01-509).
Cherfi, A., Achour, M., Cherfi, M., Otmani, S. and Morsli, A.(2015). Health risk assessment of heavy metals through consumption of vegetables irrigated with reclaimed urban wastewater in Algeria.Process Saf Environ., 98; 245-252.
Dalla Costa, R., Cossich, E. S. and Tavares, C. R. G.(2008) .Influence of the temperature, volume and type of solution in the mercury vaporization of dental amalgam residue. Sci Total Environ.,407(1); 1-6.
Drummond, J. L., Cailas, M. D. and Croke, K. (2003). Mercury generation potential from dental waste amalgam. J Dent., 31 (7); 493-501.
Gao, X. and Chen, C. T. A. (2012). Heavy metal pollution status in surface sediments of the coastal Bohai Bay. Water Res., 46(6); 1901-1911.
Hylander, L. D., Lindvall, A., Uhrberg, R., Gahnberg, L. and Lindh, U. (2006 a), Mercury recovery in situ of four different dental amalgam separators. Sci Total Environ., 366 (1) ; 320-336.
Hylander, L. D., Lindvall, A. and Gahnberg, L. (2006 b ). High mercury emissions from dental clinics despite amalgam separators. Sci Total Environ., 362 (1-3); 74-84.
Benaïssa, A., et al.
Pollution is licensed under a "Creative Commons Attribution 4.0 International (CC-BY 4.0)"
Hylander, L. D. and Goodsite, M. E. (2006 c). Environmental costs of mercury pollution. Sci Total Environ., 368 (1); 352-370.
Khan, M. U., Malik, R. N. and Muhammad, S. (2013). Human health risk from heavy metal via food crops consumption with wastewater irrigation practices in Pakistan. Chemosphere., 93(10); 2230-2238.
Kizlary, E., Iosifidis, N., Voudrias, E. and Panagiotakopoulos, D. (2005). Composition and production rate of dental solid waste in Xanthi, Greece: variability among dentist groups. Waste Manage., 25(6) ; 582-591.
Mackey, T. K., Contreras, J. T. and Liang, B. A. (2014). The Minamata Convention on Mercury: Attempting to address the global controversy of dental amalgam use and mercury waste disposal. Sci Total Environ.,472; 125-129.
Mahmood, A. and Malik, R. N. (2014). Human health risk assessment of heavy metals via consumption of contaminated vegetables collected from different irrigation sources in Lahore, Pakistan.Arab. J. Chem., 7(1); 91-99.
Megly, M. (2007). La controverse sur l'amalgame d'argent dans le grand public (Doctoral dissertation).
Mutter, J., Naumann, J., Sadaghiani, C., Walach, H. and Drasch, G. (2004). Amalgam studies: disregarding basic principles of mercury toxicity.Int J Hyg Envir Heal., 207(4); 391-397.
Official Journal of the Algerian Republic, April.(2006). No. 06 of 141 of 19 avril 2006.
Official Journal of the Algerian Republic, June. (2009). No. 09 of 209 of 11 June 2009.
Olefjord, I., Brox, B. and Jelvestam, U. (1985).Surface composition of stainless steels during anodic dissolution and passivation studied by ESCA.J Electro Chem Soc.,132 (12); 2854-2861.
Palaskar, J., Nadgir, D. V. and Shah, I. (2010). Effect of recasting of nickel–chromium alloy on its porosity. CCD., 1(4); 237.
Rahmanian, N., Ali, S. H. B., Homayoonfard, M., Ali, N. J., Rehan, M., Sadef, Y. and Nizami, A. S. (2015). Analysis of physiochemical parameters to evaluate the drinking water quality in the State of Perak, Malaysia. J Chem., 2015.
Rodier, J., Legube, B., Merlet, N., and Brunet, R. (2009). L'analyse de l'eau-9e éd.: Eaux naturelles, eaux résiduaires, eau de mer. Dunod.; 564-571.
Shraim, A., Alsuhaimi, A. and Al-Thakafy, J. T. (2011). Dental clinics: a point pollution source, not only of mercury but also of other amalgam constituents. Chemosphere.,84(8); 1133-1139.
Stone, M. E., Cohen, M. E., Liang, L. and Pang, P. (2003). Determination of methyl mercury in dental-unit wastewater. Dent Mater., 19(7); 675-679.
Tibau, A. V. and Grube, B. D. (2019). Mercury contamination from dental amalgam. JH&P., 9(22); 190612.
Vandeven, J. A. and Mcginnis, S. L. (2005). An assessment of mercury in the form of amalgam in dental wastewater in the United States. Water Air Soil Pollut.,164(1-4); 349-366.