Vazquez-Boucard_2014_J.Toxicol.Environ.Health.A_77_169

Pesticides and heavy metals were analyzed in sentinel Crassostrea gigas oysters placed in six aquaculture sites close to a contaminated agricultural region. Each site was sampled twice. Tests revealed the presence of organochlorine (OC) pesticides in the oysters at concentrations varying from 31.8 to 72.5 mug/kg for gamma-hexachlorocyclohexane (gamma-HCH); from 1.2 to 3.1 mug/kg for dichlorodiphenyldichloroethylene (4,4-DDE); from 1.6 to 2.3 mug/kg for endosulfan I; and from 1.4 to 41.2 mug/kg for endosulfan II, as well as heavy metals in concentrations that exceeded Mexican tolerance levels (405.5 to 987.8 mug/g for zinc; 4.2 to 7.3 mug/g for cadmium; and 7.2 to 9.9 mug/g for lead). Significant levels of DNA damage in oyster hemocytes were also detected. There was a significant, positive correlation between genotoxic damage and concentration of nickel or the presence of endosulfan II. Cellular viability evaluated by cytotoxic analyses was found to be high at 80%. Marked inhibition in activity of acetylcholinesterase (AChE ) and induction of glutathione S-transferase (GST) activity was noted. Data demonstrated a significant relation between AChE activity inhibition and presence of endosulfan II, gamma-HCH, copper, lead, and 4,4-DDE, as well as between AChE and GST activity at different sites.