Zinc and cadmium contamination in an Avicennia schaueriana mangrove environment: Mass balance and tissue distribution

• Published in: Marine pollution bulletin Vol. 184; p. 114170
• Main Authors: Langenbach, Tomaz, Pessoa, Denise Maria Mano, Soares, Mário Luiz Gomes, Magdaleno, Anna Carolina Ribeiro Mendes, Hagler, Allen, de Campos, Tácio Mauro Pereira
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2022
• Subjects: allometric calculations; metal phytoremediation; phytoaccumulation; toxic metal survival mechanism; toxic metal survival mechanism; allometric calculations; metal phytoremediation; phytoaccumulation
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2022.114170

The leachate pond of a Zn processing plant in Rio de Janeiro, Brazil, released Zn and Cd into a mangrove during three decades. Soil, root, stems, leaves and phloem bark samples of Avicenna schaueriana from the mangrove were collected and analyzed. Zn and Cd levels were measured by atomic absorption and were much more concentrated in soil at 76 kg/ha and 424 kg/ha respectively than in the trees (272.3 kg/ha Zn and 0.046 kg/ha Cd). This species shows a protective mechanism against uptake. The high content of Cd in the bark phloem was due to exposure to tidal flooding with high concentrations of Cd, not translocation from the roots. Allometry, and the biomass of roots, stems, leaves and bark showed that only a small percentage was phytoextracted by A. schaueriana, so this species under the described concentrations cannot phytoaccumulate and should not be used in phytoextraction. [Display omitted] •Avicenia. schaueriana has a protective mechanism against Cd and Zn uptake.•Polluted A. schaueriana accumulated Zn preferentially in roots and Cd in stems.•High metal content in bark was directly from polluted water not from translocation.•schaueriana was unable to bioaccumulate Cd and Zn at concentrations of 31 g/kg Zn and 173 mg/kg soil.•schaueriana is useless in removal of Cd and Zn from very contaminated soil.