Faunus ater (Mollusca, Gastropoda) as a potential bioindicator contamination by heavy metals

Abstract

Heavy metals are one of the most harmful elemental pollutants due to their high toxicity that can affect humans. Some of the metals can have an adverse impact on the aquatic environment, even present in a lower concentration. The present study investigates the concentration of the selected heavy metals (Cu, Zn, Cd, Pb, As, and T-Hg) in Faunus ater (Mollusca, Gastropoda) that was collected from the rivers surrounding Universiti Malaysia Terengganu area. At each station, 25 individuals were collected. A total of 100 individuals of F. ater were collected at four different stations. The Teflon bomb digestion method was used to digest the samples after mixing them with 1.5 mL of suprapur nitric acid. Heavy metal concentration is analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), model Perkin Elmer Elan 9000, and the pollution status is evaluated by Pollution Load Index (PLI). The concentration of heavy metal is varied within the stations. The average concentration of Cu, Zn, Cd, Pb, As, and T-Hg in F. ater was 29.7±1.29 µg/g dry wt., 42.1±7.77 µg/g dry wt., 0.26±0.04 µg/g dry wt., 0.58±0.08 µg/g dry wt., 2.17±021 µg/g dry wt. and 0.19±0.04 µg/g dry wt., respectively. One-way ANOVA test shows that for metal Cu, Zn, Pb, and As, there is no statistically significant difference in all stations (p > 0.05). A positive correlation of Cd, Cu, Zn, and Pb is observed with the size of F. ater, suggesting that the bioaccumulation process occurs in the F. ater. For metal and metal correlation, only Zn-Cd shows a moderate correlation compared to other metals and indicates that metals from the study area come from different sources of pollutants. The PLI value in the study area was recorded below 50, which indicated no detailed survey is needed. This study highlighted the potential use of mollusks such as F. ater as an excellent and reliable organism for heavy metal contamination indicators due to its capability to accumulate metals in body tissues.