Abstract

• Seasonal variations of As, Pb and Cd concentrations in muscle tissues of Lates calcarifer, Otolithoides pama and Polynemus paradiseus captured from Thanlwin River segment of Mon state were investigated during November 2019 to October 2020. Metal concentrations in water and sediment samples of the study sites were also assessed. Metal concentrations in extracts were determined by using Flame Atomic Absorption Spectrophotometry (FAAS) (Perkin Elmer AA Analyst 800 and Winlab – 32 software) at University Research Center (URC) in University of Yangon. Heavy metal concentrations in muscle tissues of all study fish species were below WHO standard limits. Concentration of As in water of the study site I in all seasons as well as those of the study site II also in all seasons were found higher than the WHO standard limits. As concentration in sediment of the study site I in all seasons as well as those of the study site II also in all seasons were found to be higher than the WHO standard limits. Concentration of Pb in water of the study site I in all seasons as well as those of the study site II also in all seasons were found higher than the WHO standard limits. No relationship between sizes of fish and heavy metal concentrations in L. calcarifer while negative relationship in O. pama and positive relation in P. paradiseus were found at the study site I. In the study site II, negative relationships between size of fish and As concentration in L. calcarifer, no relationships in O. pama and positive relationships between size of fish and As, Pb and Cd in P. paradiseus were observed. In the present study, transfer factor from water to muscle tissue of L. calcarifer was observed in As and Pb at the study site I and those transfer factor from sediment to muscle tissue of L. calcarifer was observed in Pb and Cd at the study site II. Transfer factor from water to muscle tissue of O. pama and P. paradiseus was observed in Cd at the study site II. However, heavy metal concentrations in muscle tissues of the study fish species were not higher than maximum permissible limits of WHO. Thus, mentioned fish species captured from the study area are generally safe for human consumption.