Assessment of Potentially Toxic Elements in Subtropical Urban Streams (Santo André, SP, Brazil)

Author(s)

Especoto, Rafaella M. T. ; Luciano, Marilena M. ; Batista, Bruno L. ; Lange, Camila N. ; Maltez, Heloisa F. ; Schiesari, Luis C. ; Franca, Marcus V. ; Fushita, angela T. ; Coelho, Lucia H. G. ; Taniwaki, Ricardo H.

• Document type: Journal article
• Source: WATER; v. 16, n. 18, p. 12-pg., 2024-09-01.

Abstract

Environmental contamination by potentially toxic elements (PTEs) poses a significant challenge, particularly in the metropolitan regions of developing countries. This issue arises from the high levels of pollution driven by industrial growth and the increased traffic from fossil fuel-powered vehicles. Even after the wastewater treatment in treatment plants, PTEs often persist, posing risks to stream structure and function. This form of pollution is persistent, long-term, and irreversible, presenting a significant challenge in terms of freshwater conservation. This study aimed to assess the water quality and PTE concentrations in urban streams in Santo Andr & eacute;, SP, Brazil, to identify the PTEs relevant to stream pollution. We analyzed the water quality in seven catchments in the Santo Andr & eacute; municipality, in the metropolitan region of S & atilde;o Paulo, Brazil. The samples were collected during the dry (2021) and rainy periods (2022), and the concentrations of potentially toxic elements (PTEs) were analyzed via inductively coupled plasma-mass spectrometry (ICP-MS). The results showed elevated electrical conductivity (429 +/- 211 mu S<middle dot>cm) and low dissolved oxygen concentrations in the streams (2.3 +/- 0.95 mu g<middle dot>L), indicating potential problems such as eutrophication and toxicity to aquatic organisms. PTE concentrations, particularly those of Mn (30.8 +/- 22.3 mu g<middle dot>L), Fe (91.1 +/- 72.1 mu g<middle dot>L), and Zn (38.1 +/- 28.7 mu g<middle dot>L), were among the highest concentrations. Seasonal variations affected the PTE concentrations, with Cr and Fe predominating during the dry season and Zn increasing during the rainy season. Associations were found between the PTE concentrations and the water pH, indicating the importance of continuous monitoring and remediation efforts. (AU)

• FAPESP's process: 20/02375-5 - Exstream Brazil: understanding climate change and agricultural intensification effects in tropical streams
• Grantee: Ricardo Hideo Taniwaki
• Support Opportunities: Regular Research Grants