Assessment of Copper Total Bioaccumulation and Genotoxicity in Boac River, Marinduque Island, Philippines Two Decades Post-Mining Disaster: Pseudodon sp. as Aquatic Fauna Indicator

Abstract

In 1996, a mining drainage tunnel burst and released copper wastes into the Boac River—rendering it dead. Two decades after the disaster, the river is now used for aquaculture farming. This study assessed the total bioaccumulation of copper and its genotoxicity in the mussel Pseudodon sp. farmed in the river. A total of 30 Pseudodon sp. were collected randomly from the downstream tributaries of the river in September 2015. Total bioaccumulation in terms of total copper concentrations was determined by atomic absorption spectrometry and the genotoxicity by micronucleus cytome assay. The total copper concentrations were present in the soft tissues (Mean + Standard Error of the Mean [SEM] of 0.0550 + 0.0003 ppm). Genotoxic indicators of nuclear alterations showed the formation of micronuclei yielding the highest frequency (Mean + SEM of 10.257 + 0.793 per 1000 cells). Binucleated, nuclear buds, agranular, apoptotic, and necrotic nuclear anomalies were likewise evident. Total copper concentrations and the frequency of the hemocyte micronuclei occurrences showed a significant relationship (r=0.366; p = 0.047) while the other nuclear abnormalities were not significantly related to the total copper concentrations. Continuous biomonitoring of mining-affected areas is necessary to safeguard people’s health from the effects of mining wastes. Keywords: bioaccumulation · copper · energy use · genotoxicity · heavy metal · mining · nuclear abnormalitie