Bioaccumulation of Metals in Fish Collected from Macapá Urban Aquatic Environments (Brazilian Amazon) and the Risks to Human Health

The city of Macapá in the Brazilian Amazon faces critical aquatic pollution challenges due to inadequate sanitation infrastructure, leading to heavy metal contamination in fish within its urban water bodies. This study evaluates concentrations of metals (Cu, Cd, Cr, Fe, Mn, Ni, Pb, Zn, Hg) in muscle tissues of fish from igarapés, floodplain lakes, and canals. Samples were collected from six sites to investigate the bioaccumulation of these metals and their potential human health risks. Using Atomic Absorption Spectrometry and Inductively Coupled Plasma Optical Emission Spectrometry for Hg, metal levels were analyzed in three carnivorous and seven omnivorous fish species. Cd concentrations in several species exceeded safety thresholds for human consumption, while the estimated daily intake (EDI) of Hg also surpassed reference doses. Risk assessment combining the risk quotient (RQ) for individual metals and the risk index (RI) for metal mixtures indicated considerable health risks associated with consuming fish from these contaminated waters. These findings reveal concerning exposure to contaminants, underscoring the need for environmental management and ongoing monitoring to protect public health in vulnerable urban areas.