Concentrations of selected trace metals (Cu, Pb, Zn), organochlorines (PCBs, HCB) and total PAHs in mangrove oysters from the Pacific Coast of Mexico: an overview

Samples of resident mangrove oysters Crassostrea corteziensis were collected from each of 14 sites along the Pacific coast of Mexico during April May 1996, and selected contaminant concentrations were measured. High lead concentrations were recorded in oysters from the center and southern Sinaloa coast, while the highest Zn concentrations were found at Altata-Ensenada del Pabellon Lagoon, Mazatlan Port, Yavaros Lagoon, and Ceuta Lagoon. The highest copper concentrations were found at Altata-Ensenada del Pabellon Lagoon, Navachiste Lagoon, and Nueva Vallarta. Highest PCB concentrations were found in oysters collected near suburban centers, and the main chemical forms were Aroclor 1242, Aroclor 1254, and Aroclor 1260. High hexachlorobenzene (HCB) concentrations were measured in oysters collected from lagoons bordered by extensive agricultural lands, while highest PAH concentrations were found at Santa Maria Lagoon and Altata-Ensenada del Pabellon Lagoon. A significant linear correlation was discerned between Pb and PAHs, which suggested the impact of small boat exhausts.