Temporal trends of persistent organic pollutant contamination in Franciscana dolphins from the Southwestern Atlantic

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Montone, Rosalinda C. ; Alonso, Mariana B. ; Santos, Marcos Cesar O. ; Mendez-Fernandez, Paula ; Taniguchi, Satie ; Barbosa, Ana Paula M. ; Goncalves, Renato M. ; Padilha, Janeide de Assis ; Bertozzi, Carolina ; da Silva, Josilene ; Marigo, Juliana ; Pereira, Antonio Derley S. ; Lourenco, Rafael A.

• Document type: Journal article
• Source: Environmental Research; v. 216, p. 12-pg., 2023-01-01.

Abstract

Persistent organic pollutants (POPs) were analyzed in 136 blubber samples of Franciscana dolphins from Brazil (Pontoporia blainvillei), which is the most threatened dolphin in the Southwestern Atlantic. The dolphins were caught by the fishery fleet and collected from 2000 to 2018 in three regions of Sa similar to o Paulo state: northern Sa similar to o Paulo (SPN), central Sa similar to o Paulo (SPC), and southern Sa similar to o Paulo (SPS). The POPs analyzed in this study were polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDTs), Mirex, hexachlorobenzene (HCB), chlordane compounds (CHLs), hexachlorocyclohexane isomers (HCHs), and polybrominated diphenyl ethers (PBDEs). The concentrations ranged from 36 to 7200 ng g-1 lipid weight (lw) and 113-42200 ng g-1 lw for predominant compounds DDTs and PCBs, respectively. Similar profiles of PCB congeners were observed with a predominance of hexachlorinated compounds, representing approximately 50% of the total PCB amount; the highest PCB concentrations were observed from Baixada Santista (SPC) proximate to a highly urbanized and industrial coastal area. Significant differences were observed between the sexes and maturity of dolphins, mainly for PCBs, DDTs, and Mirex. In general, POPs other than HCB in Franciscana dolphins showed downward tem-poral trends, matching the regulatory periods for restricting and/or banning these compounds. Although POP concentrations are declining, PCB levels remain high in small dolphins, suggesting adverse health effects on Franciscanas. As organic contaminants are one of the numerous threats Franciscanas have been vulnerable to along the Brazilian coast, we recommend monitoring POPs levels every five years to check for declining (or stabilizing) trends. (AU)

• FAPESP's process: 16/18348-1 - Multi-User Equipment approved in grant 2015/17763-2: triple quadrupole gas chromatograph-mass spectrometer (GC/MS/MS)
• Grantee: Márcia Caruso Bícego
• Support Opportunities: Multi-user Equipment Program