Distribution and Accumulation of Trace Elements in Organs of Juvenile Fishes from a Freshwater System (Paraná River, South America)

Muscle oxidative stress, neurotoxicity and human health risks from consuming fish exposed to metallic settleable atmospheric particulate matter

The concentration of metals/metalloids in settleable particulate matter (SePM) from industrial area and in the muscles were determined in the estuarine fish, Centropomus parallelus, after 96 h-exposure to different SePM concentrations. Antioxidant defenses, oxidative damage and neurotoxicity were also determined. The risk for human consumption was evaluated by estimating daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) and compared with fish collected close to the industries. Eighteen metals/metalloids were quantified in SePM and the muscles. In red muscle, the antioxidant enzymes were unchanged, and the acetylcholinesterase (AChE) activity and protein carbonyls (PC) increased. In white muscle, the glutathione-S-transferase (GST) activity and glutathione content (GSH) decreased, PC levels and lipid peroxidation (LPO) increased; the AChE was unchanged. Metals/metalloids bioaccumulated in muscles induced oxidative damage which may affect muscle function and consequently, fish performance. After short-term exposure to SePM there was no risk for human consumption. However, the EDI of fish collected in field exceeded the acceptable DI for children concerning to As and Hg. HI were lower than 1 revealing no carcinogenic risk.

Assessment of trace and macroelement accumulation in cyprinid juveniles as bioindicators of aquatic pollution: effects of diets and habitat preferences

Juveniles of three cyprinids with various diets and habitat preferences were collected from the Szamos River (Hungary) during a period of pollution in November 2013: the herbivorous, benthic nase (Chondrostoma nasus), the benthivorous, benthic barbel (Barbus barbus), and the omnivorous, pelagic chub (Squalius cephalus). Our study aimed to assess the accumulation of these elements across species with varying diets and habitat preferences, as well as their potential role in biomonitoring efforts. The Ca, K, Mg, Na, Cd, Cr, Cu, Fe, Mn, Pb, Sr, and Zn concentration was analyzed in muscle, gills, and liver using MP-AES. The muscle and gill concentrations of Cr, Cu, Fe, and Zn increased with trophic level. At the same time, several differences were found among the trace element patterns related to habitat preferences. The trace elements, including Cd, Pb, and Zn, which exceeded threshold concentrations in the water, exhibited higher accumulations mainly in the muscle and gills of the pelagic chub. Furthermore, the elevated concentrations of trace elements in sediments (Cr, Cu, Mn) demonstrated higher accumulation in the benthic nase and barbel. Our findings show habitat preference as a key factor in juvenile bioindicator capability, advocating for the simultaneous use of pelagic and benthic juveniles to assess water and sediment pollution status.

Essential and non-essential elements in marine silverside Odontesthes argentinensis from southwestern Atlantic coast: Tissues bioaccumulation, biomagnification and public health risk assessment

In order to assess the metal pollution in the southwestern Atlantic coast, levels of eleven metals: Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, and Zn and one metalloid: As in water and tissues of Odontesthes argentinensis from the Samborombón Bay (SB) and Partido de La Costa (PC) were examined. Additionally, bioconcentration, and bioaccumulation factors, estimated daily intake (EDI) for adults and children, and the hazard risk for fishermen and general populations were evaluated. Cadmium, Cu and Zn levels in the water samples exceeded the limits established by international guidelines for the protection of aquatic life in marine environments (CCME). The liver showed the highest concentrations of As, Cu, Fe, and Zn, while muscle showed the least levels of all elements examined. Bioaccumulation of Cd, Cu, Mn, Pb and Zn were observed in all tissues, while Ba and Sr bioaccumulated significantly in the gills. The fish δ15N values significantly varied between sites, however, no biodilution or biomagnification was observed. The Target Hazard Quotients (THQ) and the Carcinogenic Risk (CR) indices suggest that there is no human health risk to the fishermen and general populations from the O. argentinensis consumption. Furthermore, As (27%) and Cr (33%) concentrations in silversides from PC and SB, respectively, exceeded the levels recommended by local and international guidelines.

Essential and toxic elements in juvenile migratory commercial fish species in the Paraná River alluvial valley (South America): an approach for aquatic environmental monitoring

The Paraná River is the sixth largest in the world, and the lower section of the river is one of the largest and most productive floodplain wetlands in South America. The alluvial plain is an important habitat for nursery and feeding areas for commercial fish; however, it has been heavily anthropized due to industries, agricultural activities, and the growth and expansion of metropolitan areas. The aim of this study was to determine element accumulation (As, Cd, Cr, Cu, Fe, Mn, Pb, and Zn) in young-of-the-year fish muscle from a floodplain lagoon of the lower Paraná River (Argentina) during summer and winter seasons, in relation with abiotic matrices (water and sediment). Four commercial fish species were assessed: sábalo (Prochilodus lineatus), boga (Megaleporinus obtusidens), dorado (Salminus brasiliensis), and pirapitá (Brycon orbignyanus). The concentrations of eight elements were detected by quadrupole inductively coupled plasma mass spectrometry. In water samples, Cd, Cr, Mn, Fe, and Zn levels were under the permissible limits for aquatic biota protection in both seasons, except for Pb (> 1 μg L-1) and Cu (> 2 μg L-1). In sediment, the average concentrations of all elements were under the limits set by national and international regulatory authorities. Differences in elemental concentrations between species and seasons were found. In general, the levels of elements in water were higher in summer than in winter, while in sediment, the lowest concentrations of elements were detected during the summer. The order of element concentration in fish muscle was Cd (0.01-0.04 μg g-1) < As (0.02-0.16 μg g-1) < Pb (0.03-0.23 μg g-1) < Mn (0.77-4.32 μg g-1) < Cu (1.01-4.07 μg g-1) < Cr (1.09-4.30 μg g-1) < Zn (15.8-31.7 μg g -1) < Fe (12.6-49.7 μg g-1). The accumulation assessment showed that the four fish species significantly accumulate Cr, Cu and Zn, and As and Zn from water and sediment, respectively. The correlation analysis showed a relationship between fish size and As, Cr, Cu, Fe, Mn, and Zn concentrations. Similarly, the highest values of element concentrations in muscle were detected during the summer when the fishes are early juveniles. The level of As, Cd, and Pb detected in B. orbignyanus, M. obtusidens, and P. lineatus juveniles suggested that these species had the potential to be used as biomarkers for assessing accumulation of toxic elements in the environment. Also, this study reveals that the accumulation patterns differ between size and fish species, which should be a considered insight at the moment of selecting a bioindicator to monitor pollution in the ecosystem.