Bioaccumulation and speciation of arsenic in plankton from tropical soda lakes along a salinity gradient

José Lucas Martins Viana; Débora Aparecida Steffler; Amauris Hechavarría Hernández; Juliana Dos Santos Costa; Thierry Alexandre Pellegrinetti; Erick Christian Rodrigues de Jesus; Marianna Cancian; Marli Fátima Fiore; Ary T Rezende-Filho; Alessandra Sussulini; Laurent Barbiero; Amauri Antonio Menegario; Anne Helene Fostier

doi:10.1016/j.scitotenv.2023.165189

Bioaccumulation and speciation of arsenic in plankton from tropical soda lakes along a salinity gradient

Sci Total Environ. 2023 Oct 15:895:165189. doi: 10.1016/j.scitotenv.2023.165189. Epub 2023 Jun 28.

Authors

Affiliations

¹ Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil. Electronic address: lucas_martinsj@hotmail.com.
² Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil.
³ Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenario 303, 13400-970 Piracicaba, SP, Brazil.
⁴ Federal University of South Mato Grosso (UFMS), Campo Grande, MS, Brazil.
⁵ Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil; Université P. Sabatier, IRD, CNRS, OMP, Géoscience Environnement Toulouse (GET), 14 Avenue Edouard Belin, F31400 Toulouse, France; Center of Sciences and Technologies for Sustainability, São Carlos Federal University, Sorocaba, SP 18052-780, Brazil.
⁶ São Paulo State University (UNESP), Environmental Studies Center, Av. 24-A, 1515, 13506-900 Rio Claro, SP, Brazil.

PMID: 37391131
DOI: 10.1016/j.scitotenv.2023.165189

Abstract

Uptake and transformation of arsenic (As) by living organisms can alter its distribution and biogeochemical cycles in the environment. Although well known for its toxicity, several aspects of As accumulation and biological transformation by field species are still little explored. In this study, the bioaccumulation and speciation of As in phytoplankton and zooplankton from five soda lakes in the Brazilian Pantanal wetland were studied. Such lakes exhibited contrasting biogeochemical characteristics along an environmental gradient. Additionally, the influence of contrasting climatic events was assessed by collecting samples during an exceptional drought in 2017 and a flood in 2018. Total As (As_Tot) content and speciation were determined using spectrometric techniques, while a suspect screening of organoarsenicals in plankton samples was carried out by high-resolution mass spectrometry. Results showed that As_Tot content ranged from 16.9 to 62.0 mg kg^-1 during the dry period and from 2.4 to 12.3 mg kg^-1 during the wet period. The bioconcentration and bioaccumulation factors (BCF and BAF) in phytoplankton and zooplankton were found to be highly dependent on the lake typology, which is influenced by an ongoing evapoconcentration process in the region. Eutrophic and As-enriched lakes exhibited the lowest BCF and BAF values, possibly due to the formation of non-labile As complexes with organic matter or limited uptake of As by plankton caused by high salinity stress. The season played a decisive role in the results, as significantly higher BCF and BAF values were observed during the flooding event when the concentration of dissolved As in water was low. The diversity of As species was found to be dependent on the lake typology and on the resident biological community, cyanobacteria being responsible for a significant portion of As metabolism. Arsenosugars and their degradation products were detected in both phytoplankton and zooplankton, providing evidence for previously reported detoxification pathways. Although no biomagnification pattern was observed, the diet seemed to be an important exposure pathway for zooplankton.

Keywords: Eutrophication; Organic matter; Phytoplankton; Suspect screening; Zooplankton.

MeSH terms

Animals
Arsenic* / metabolism
Bioaccumulation
Lakes / chemistry
Phytoplankton / metabolism
Plankton* / chemistry
Salinity
Zooplankton / metabolism

Substances

Arsenic