Bioaccumulation of cd and hg in Muscle of Juvenile Pacific Sharpnose Shark Rhizoprionodon longurio from the SE Gulf of California.

In this study, the concentrations of Cd and Hg were measured in muscle of juvenile individuals at an importan fishing ground in southeastern Gulf of California to assess the health risk to human consumers considering elemental levels and rate of shark consumption in NW Mexico. Twenty-eight individuals were sampled in September 2019. Quantification of Hg was made by cold vapor-atomic absorption spectrophotometry, analyses of Cd were made by graphite furnace atomic absorption spectrophotometry. In general, average Hg (1.27 µg g-1 dry weight) concentrations were higher than Cd (0.059). In comparison to results of Cd and Hg in muscle of several species of genus Rhizoprionodon sp., our reported concentrations were comparable. Maximum permissible limits (Cd 0.5 and Hg 0.5 µg g-1 wet weight) in fish products for human consumption were not exceeded. Health risk assessment to shark consumers indicated that Hg is of more concern than Cd but no hazards exist.

Health risk associated to dietary intake of mercury in selected coastal areas of Mexico.

A hazard quotient (HQ) was evaluated for Mexican population considering Hg levels and consumption rates. Fish and shrimp were caught in selected coastal areas. HQ's ranged from 0.004 to 0.01 in shrimp; from 0.004 to 1.04 in fish from NW Mexico; and from 0.02 to 0.19 in fish from the Gulf of Mexico. Highest HQ in fish were found in carnivorous fish Caranx caninus (HQ = 0.71) and Sphyrna lewini (HQ = 1.04) from NW Mexico. A more accurate study should be made considering organic Hg, contribution of Hg from other sources, and consumption rates according to age, sex and economic status.