The results of the study “Assessment of Arsenic Exposure to the Population of Paracatu” were unveiled on January 27th, during a meeting held in the city with representatives from the media, community leaders and the public authorities. According to data obtained from a seven-year study held by world-leading international and national arsenic and environmental scientists, exposure to arsenic in Paracatu is low.
The assessment’s approach was based on analyzing exposure in the local population in terms of the main sources of exposure: inhalation of dust; drinking water, food and unintentional soil ingestion. The study includes the calculation of the relative contribution of various exposure pathways to the total daily arsenic intake, and its main conclusions are:
- Exposure to arsenic is considered low, as total exposure (intake), including all sources, is below the 10% reference dose established by the World Health Organization (WHO).
- The risk to human health is low, as exposure is low.
- The contribution from mining activities through dust and soil to arsenic exposure is lower than the exposure through the ingestion of food and water. Furthermore, as it is also lower than the 2% reference dose established by the World Health Organization (WHO), the risk to human health is low.
- Low levels of arsenic exposure through water: The average arsenic concentration of 1.34 µg/L (micrograms/liter) in samples of surface wells and community drinking water is seven times lower than the 10 µg/L limit established by Brazilian regulations and the World Health Organization (WHO). The majority of arsenic concentration values in water were below 0.3 µg/L. These results indicate that exposure through water consumption, which is internationally considered as the most important form of arsenic contamination, does not present significant risks to human health.
- The calculation of the maximum total daily arsenic intake through the various exposure pathways, both in adults and children, is of around 8% of the BMDL5 (Benchmark Dose Lower Limit) of 3 μg/kg pc/ day (micrograms/kilogram of body weight a day).
- Risk of cancer through arsenic is low: The risk of an increase in cancer associated to total maximum exposure of 0.25 μg/kg pc (microgram/kilogram of body weight), taking into consideration all exposure pathways (soil, dust, food and water) in Paracatu is similar (among adults) or below (among children) to the risk of drinking water that contains 10 µg/L of arsenic – a concentration that is considered as a safe limit by WHO and by Brazilian legislation.
This study is part of a number of measures that Kinross takes to ensure the safety and sustainability of its operations. These measures include rigorous environmental monitoring, dust control procedures, regular reporting back to environmental authorities, an annual third-party review of our tailings facilities, and voluntary, bi-annual medical testing for all our employees. Kinross follows well-established mining practices and is committed to ensuring both the safety of the environment and local community.
The project leaders
The project has been led by Professors Virginia Ciminelli, an environmental hydrometallurgist from the Department of Metallurgical and Materials Engineering at the Federal University of Minas Gerais – UFMG; Massimo Gasparon, a geochemist from the School of Earth Sciences at The University of Queensland (Australia); and Professor Jack Ng, a certified toxicologist from the National Research Centre for Environmental Toxicology at The University of Queensland.
Professor Jack Ng Professor, The University of Queensland, National Research Centre for Environmental Toxicology, Australia; Research Group Leader for Risk Assessment and Intervention and Program Leader of Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE). Professor Ng is one of Australia’s few certified toxicologists (DABT), with a PhD in Chemistry and Environmental Toxicology. He had a significant contribution to scientific knowledge about the toxicity of arsenic, following his development of the first animal model suitable to determine the carcinogenic effects of arsenic. He has vast experience in Environmental and Chemical Toxicology, heavy metals and natural toxins, with emphasis on speciation and bioavailability as key parameters for risk assessment. A large portion of his research aims at creating data to fill the gaps in risk-assessment studies. Jack is the author of several book chapters and of over 300 scientific publications and technical opinions and reports, including risk-assessments of contaminated areas for the industry and government agencies. He was invited by WHO to contribute with three chapters about arsenic for the document IPCS EHC (Environmental Health Criteria) and to coordinate the document’s execution. He was task group member and co-author of the IARC Monograph Vol 84 (2004) “Some drinking water disinfectants and contaminants including arsenic”. He was the coordinating editor and co-author of the WHO IPCS Environmental Health Criteria of Arsenic and Arsenic Compounds (2001), – Some Drinking-water Disinfectants and Contaminants, including Arsenic, Expert Committee and co-author WHO/FAO JECFA technical report (2010) – Technical report of the 72nd meeting of Joint WHO/FAO Expert Committee on Food Additives, toxicological evaluations of acrylamide, arsenic, deoxynivalenol, furan, mercury, and perchlorate. He works as an expert advisor for the WHO/OAA Joint Expert Committee (2011-2016). He was guest-editor in a special issue about arsenic of the Toxicology Letters magazine (2002) and in a special issue on metals and metalloids also for Toxicology Letters (2003), as well as contributor in a special issue about arsenic for the Journal of Hazardous Materials (2012). He was appointed by Wiley VCH Publisher as one of three editors for the Merian manual series on Elements and their Compounds in the Environment (2012-2014); he is Chief-Editor at the Environmental Geochemistry and Health Journal; a member of the editorial committee of the Toxicology Journal and a proofreader for several international scientific publications.
Dr. Massimo Gasparon is an Associate Professor in Geochemistry at the School of Earth Sciences of The University of Queensland, Director of the Environmental Geochemistry Laboratory at The University of Queensland and Chief Investigator for the Australian National Centre in Groundwater Research and Training. He has vast experience in the drawing up and implementation of sampling, analysis and monitoring programs for environmental risk-assessment, with a particular interest in establishing baseline levels for contaminants in pristine and impacted areas. His current research is focused on studying and modeling rock-fluid interaction (complexation, adsorption and kinetics) in superficial environments; the analysis of trace metals in ultra-trace levels and in environmental matrices and in difficult environmental matrices; and environmental impact assessment.
Dra. Virginia S. T. Ciminelli is a Professor at the Department of Metallurgical and Materials Engineering of the Federal University of Minas Gerais (UFMG) and Coordinator of the National Institute of Science and Technology on Mineral Resources, Water and Biodiversity (INCT-Acqua), a network comprised of 30 institutions in Brazil and abroad. Virginia is a member of the Brazilian Academy of Sciences, Member of the National Academy of Engineering, Brazil and Foreign Member of the US National Academy of Engineering; she was the main Brazilian participant at CYTED – Arsenic in Ibero-America (47 groups from 17 countries); she is the coauthor of 200 scientific publications (many of which about arsenic fixation/remobilization) and a supervisor of 45 theses/dissertations (12 of which about arsenic) and of PhD research works; she was the recipient of several awards and prizes, such as the Mercosur Award of Science and Technology, Integration Category (“The problem of Arsenic in Mercosur: An integrated and multidisciplinary approach to research and search for a solution” in 2011, for her work at the IBEROARSEN network with Latin America and Iberia Peninsula researchers; GEMS Alumni Achievement Award from the University of Pensilvania (2004); and FUNDEP (2008). Ciminelli was a guest-speaker at various events in Brazil and abroad. A member of the editorial board at the Hydrometallurgy Journal and other publications; She has coordinated several events and sessions in Brazil and abroad as vice-president of the international event Hydroprocess 2012 (Chile) and joint-coordinator at the session Arsenic in Mining in 2012 (Australia) and a guest-speaker for the plenary session of the event Arsenic 2014, in Buenos Aires. Her research includes the development and adoption of hydrometallurgy processes and the treatment of aqueous effluents, with emphasis on thermodynamics, kinetics and molecular modeling of dissolution reactions, sorption, precipitation, electrowinning and in particular, phenomena associated to sulfate oxidation and arsenic fixation.