Heavy metal concentration and human risk assessment of rock oyster in the coastal area of Ha Long City, Quang Ninh Province

Abstract

The accumulation of heavy metals in rock oyster is a significant concern, particularly because rock oysters are a common food source for local people. This study evaluated the concentrations of 10 heavy metals in oysters and assessed the associated health risks from their consumption. The target hazard quotient (THQ) methodology, as established by the United States Environmental Protection Agency (US EPA), was utilized to determine the level of potential health risks. The findings revealed that among the heavy metals studied, zinc (Zn) and copper (Cu) were found to accumulate at significantly high concentrations, with values of 402.9008 mg/kg and 100.7288 mg/kg, respectively. Other heavy metal values, ranged from 0.1166 to 1.897 mg/kg, which is a comparatively low level. The levels of cadmium (Cd) and lead (Pb) were within the allowable limits outlined in Ministry of Health QCVN 8-2:2011/BYT. However, the THQ values for arsenic (As) exceed 1 for both medium and high consumption levels, signaling a potential health risk for consumers. The THQ values for other heavy metals remained below 1, indicating minimal health concerns from these elements individually. In addition, the total THQ for all heavy metals combined exceeded 1 across all consumption scenarios, underscoring a cumulative risk to consumer health.