Original research articleToxic element determination in fish from Paraná River Delta (Argentina) by neutron activation analysis: Tissue distribution and accumulation and health risk assessment by direct consumption

- As, Co, Fe, Hg, and Zn were determined by NAA in tissues of fish.
- Elements accumulation order in muscle was Zn > Fe > As > Hg > Co.
- Highest concentrations of As and Hg were found in liver and muscle.
- The levels of Hg in muscle were above the international and national guidelines.
- The total THQ was higher than 1 for fishermen population.

The concentrations of As, Co, Fe, Hg, and Zn were determined by INAA in muscle, gills, liver and scale of silversides (Odontesthes bonariensis) and sardine (Lycengraulis grossidens) from Paraná River Delta (Argentina) and the human health risk related to the consumption of muscle was evaluated. Detection limits were among 0.001 and 0.3 mg/kg, the RSD values were below 12% and certified reference material showing good accuracy. Considering all tissues and species, elements concentrations (mg/kg, ww) were: As: (0.35-1.30), Co (0.008-0.29), Fe (2.22-369.5), Hg (nd-1.11) and Zn (5.83-187.6). Most of the trace elements tended to be higher in L. grossidens, except for Co, Fe and Zn in gills and Hg in liver. Elements accumulation order for both species was Zn > Fe > As > Hg > Co in muscle and scale and Fe > Zn > As > Hg > Co for gills and liver. The highest concentrations of As and Co were found in liver, Hg in muscle and liver, Fe and Zn in liver and scale for sardine, and gills and liver for silversides. The levels of Hg in muscle were above the maximum recommended established by national or international guidelines. The THQ of each metal and the total THQ due to fish consumption were less than 1 for general population, suggesting that people would not experience significant health risks. However, for fishermen group, the total THQ was higher than 1, indicating the potential health risks of chronic exposure to contaminants.