Mercury variation over the last century in dated sediment cores across Brazil: a systematic review of literature

Abstract

Mercury (Hg) is a well know element due its toxicity to both environment and humans. Also, mercury has a high persistence in the environment, and therefore, it is essential to monitor its presence on environmental matrices, such as water, soils and sediments. Sediment cores can provide a useful tool when monitoring water bodies for the presence of mercury since, when coupled with geochronological techniques, it is possible to analyze the temporal variation of Hg during a certain period. Thus, the objective of this work was to perform a systematic review about papers that analyzed the presence of Hg in dated sediment cores in Brazil. The review was performed in the following databases: Scielo, PubMed, Science Direct and Scopus. We searched for papers published between 2011 and 2020. In total, we found 217 articles, that after the application of successive filtration criteria, were reduced to 13 articles. The majority of the papers showed a tendency of increase in the concentration of Hg. We also performed a risk assessment that indicates that some places have Hg concentrations above quality criteria established for sediments. Regarding the sources, all the papers that presented a tendency of increase in Hg concentrations considered this as consequence of anthropogenic activities, such as chlor-alkali industries and deforestation.

Keywords:

• mercury
• ²¹⁰Pb geochronology
• environmental monitoring
• sediment

Acknowledgment

We are thankful to L. Agnelo who provided a careful language revision of the manuscript. We also thank the two anonymous reviewers for their careful revision of the manuscript.

Additional information

Funding

Coordenação de Aperfeiçoamento de pessoal de Nível Superior (CAPES) - Grant No. 001.