Assessment of heavy metals found in commonly consumed fishes from Lake Lanao, Philippines

Abstract

This study was carried out to assess potential heavy metal contamination in the muscles of three commonly consumed fish species in Lake Lanao and to determine associated health risks that may endanger local community residents who consume these fishes. The concentrations of Arsenic (As), Cadmium (Cd), Chromium (Cr), Mercury (Hg) and Lead (Pb) were assessed in the muscles of Glossogobius giurus, Oreochromis niloticus and Giuris margaritacea and were measured via atomic absorption spectrophotometry. Statistical analysis showed that heavy metal concentrations in the muscles of the three fish species collected from the two different locations in the lake are not significantly different (P>0.05) except for O. niloticus. Recorded amounts of the five heavy metals in the present study were lower than the maximum and standard levels except for Pb. Four (As, Cd, Cr, and Hg) among the five pollutants of concern obtained Non-carcinogenic Hazard Quotient (NHQ) values that are less than one, while NHQ values for Pb range between 815.6 and 1396.03 for all fish samples obtained from both sampling stations. The continued consumption of G. giuris, O. niloticus and G. margaritacea collected from Marawi City and Tugaya, Lanao del Sur posed a high likelihood for local residents to contract adverse non-carcinogenic impacts, specifically by Pb. This does not necessarily hold true for the whole of Lake Lanao however, due to limitations related to representativeness. Steps should be taken to manage the risks posed by the consumption of G. giuris, O. niloticus, and G. margaritacea from Marawi City and Tugaya, Lanao del Sur, especially in consideration of vulnerable groups such as children, pregnant women and their developing fetus, and people with existing health conditions.