Inter‐and intra-stock bioaccumulation of anionic arsenic species in an endangered catfish from South American estuaries: risk assessment through consumption

Abstract

Monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), inorganic arsenic (iAs), and non-toxic species (i.e. arsenobetaine) were determined by HPLC-ICP-MS as mg kg−1 wet weight in muscle, liver and gill of catfish (Genidens barbus) from Argentina (N = 12) and from Brazil (N = 11). Concentrations (mean ± standard deviation) of non-toxic arsenic species were 10.4 ± 2.89 and 14.9 ± 5.94 for muscle, 1.48 ± 0.58 and 2.21 ± 1.24 for liver, and 0.66 ± 0.39 and 2.44 ± 1.93 for gill, respectively, for Argentina and Brazil, and represented 95.5%–99.5% of the total arsenic for each tissue. Toxic arsenic (iAs) levels were 0.048 and 0.013 for muscle, 0.24 and 0.011 for liver, and 0.037 and 0.012 for gill and represented 0.45–4.93 % of the total arsenic for Argentina and 0.24-0.60 % for Brazil. The iAs concentrations for all tissues were below the recommended international and local legislations of 0.1-1.0. Based on iAs in muscle, target hazard quotients were 0.032 and 0.018, respectively, for Argentina and Brazil. Risks of external (skin) cancer and internal (bladder/lung) cancer were 1.4 × 10-5 and 1.9 × 10-4 for Argentina and 7.3 × 10-6 and 9.9 × 10-5 for Brazil, suggesting that populations may be exposed to an internal cancer risk through chronic consumption. Risk assessments need to be based on specific fish and their iAs concentrations in muscle.