Accumulation of Trace Metals in Mangrove Plant Soneratia Caseoralis in Songkhla Lake, Thailand

Abstract

Mangrove sediment and mangrove plant Soneratia caseolaris in Songkhla Lake, Thailand have been increasingly threatened by trace metal pollution. Mangroves receive trace metal pollution from upstream areas and the sea. However, little is known about the mangrove plant's capacity to uptake and store trace metals. In this study, the concentrations of As, Cd, Pb and Zn in mangrove plant parts (leaf, root, and bark) of Sonneratia caseolaris and sediments were determined. Sediment and plant samples were digested using total metal concentration procedure and ICPMS techniques. It was found that the maximum values of total concentrations of As in mangrove sediments were classified as heavily polluted according to USEPA. The highest concentrations of As and Zn were found to be in bark whereas Cd and Pb in the root. The fractions of all the metals were measured using BCR techniques and their results revealed that the bioavailability fraction was greater than the residual fraction. The order of the amounts of trace metals present in the fractions was as follows; As: Oxidizable > Reducible > Residual > Exchangeable and the order of Cd: Exchangeable > Reducible > Oxidizable > Residual. Both BCF and TF values showed limited accumulation of these elements in their aboveground parts and thus presented a low food chain hazard except at Phawong and U-Taphao canals.

Microplastics and heavy metals in the sediment of Songkhla Lagoon: distribution and risk assessment

“…These rivers collect urban waste as well as industrial and agricultural waste. The potential sources of heavy metal in the sediment of Songkhla Lagoon (the outer section) include municipal waste from the large and rapidly expanding cities of Songkhla province, as well as agricultural and industrial discharges transported via the U-Taphao canal (Sompongchaiyakul and Sirinawin, 2007;Pradit et al, 2018). As and Cu are employed in the parawood business as wood preservatives near to the lagoon Potential ecological risk indices (R¡) of lagoon sediment.…”

Sedimentary History of Trace Metals Over the Past Half-Century in Songkhla Lake, Western Coast of the Gulf of Thailand: Anthropogenic Impacts and Contamination Assessment

“…These studies have shown that canals and their vicinities were associated with abundant trace elements because of municipal, agricultural, and industrial discharges entering the lake through the canals. Furthermore, a recent study, which analyzing the concentrations of As, Cd, Pb, and Zn in mangrove plants (leaves, roots, and bark) and sediments, revealed heavy pollution of As (Pradit et al, 2018). However, research on sedimentary trace metal history, which can help improve understanding of the influence of human activities, remains scarce.…”