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.

Synthesis and characterization of hybrid-magnetic nanoparticles and their application for removal of arsenic from groundwater.

Multiwall carbon nanotubes (MWCNTs) were oxidized with different agents and a characterization study was carried out. Then, hybrid-magnetic nanoparticles (HMNPs) were synthesized as iron oxide supported on the selected multiwalled carbon nanotubes (MWCNTs-Fe3O4) obtained from MWCNTs oxidized with HNO3. The HMNPs characterization revealed the presence of iron oxide as magnetite onto the MWCNTs surfaces. These HMNPs were used for arsenic removal from groundwater. The adsorption process variables were optimized (concentration of NPs, contact time, and pH), and these systems could remove 39.93 mg As/g adsorbent. Therefore, these nanoparticles appear as a good alternative for removing arsenic from water samples.

Health risk assessment and differential distribution of Arsenic and metals in organs of Urophycis brasiliensis a commercial fish from Southwestern Atlantic coast.

The concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, and Zn were analyzed in muscle, gills, and liver of Urophycis brasiliensis from two Southwestern Atlantic catch areas (Brazil and Argentina). Additionally, the health risk of general and fishermen populations through fish consumption was estimated. The gills showed the highest concentrations of most of the elements, followed by the liver. With the exception of As, the muscle was the organ with the lowest concentrations of most elements. Levels of arsenic in muscle of U. brasiliensis were exceeded the maximum permissible levels for human consumption recommended by local and international guidelines. The target hazard quotients (THQs) and the carcinogenic risk (CR) showed no risk for individual and all elements. These results highlight the importance of arsenic speciation in U. brasiliensis muscle in order to generate more reliable risk estimates.

Experiences in transitioning a testing laboratoryto the new ISO/IEC 17025:2017 standard.

Since its inception, the international quality standard ISO/IEC 17025 has been revised twice. The most recent edition adopted a new structure to align with other conformity assessment and quality management standards, harmonized the terminology with the International Vocabulary of Metrology and introduced the concept of risk-based thinking. This paper disseminates the experience of the IAEA Radiation Safety Technical Services Laboratory in successful transition and re-accreditation to ISO/IEC 17025:2017. It covers all stages of the transition cycle: from conducting a gap analysis between the existing quality system and the requirements in the revised standard, updating the corresponding quality documents, developing training and communication plans for laboratory personnel, to monitoring the changes and improving the system through auditing, management review and participation in proficiency testing schemes. Lessons learned about building operational resilience and maintaining a business continuity management system to prepare for, respond to, and recover from disruptions are considered.

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

The concentrations of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn (TE) in four juvenile fishes (Acestrorhynchus pantaneiro, Salminus brasiliensis, Brycon orbignyanus, and Megaleporinus obtusidens) and associated sediment water from the Lower Paraná River were measured. For muscle, gills, and liver fishes, the TE accumulation in the muscle, gills, and liver was evaluated. The TE concentration was measured by quadrupolar inductively coupled plasma mass spectrometry (Q-ICP-MS). Cadmium (0.25 ± 0.07 µg L-1), Cu (3.00 ± 1.44 µg L-1), Fe (612 ± 69 µg L-1), and Pb (1.92 ± 1.20 µg L-1) in water and As (4.1-6.9 µg g-1), Cr (20.1-31.4 µg g-1), Cu (10.7-19.2 µg g-1), Mn (351.3-482.2 µg g-1), and Ni (24.5 ± 10.9 µg g-1) in sediments exceeded the guide values for the conservation of aquatic life. In general, muscle of omnivorous species (B. orbignyanus and M. obtusidens) showed higher values of elements than those of carnivorous species (A. pantaneiro and S. brasiliensis). However, TE concentrations varied with fish species and organs. Independently of the examined species, the highest concentrations of Cr and Pb were in the muscle and gills, respectively. Cadmium, Cu, and Fe concentrations were higher in the liver than in gills and muscle in all four fish species. These results were consistent with the tissue selectivity index analyzed. For the four species, major essential elements showed the highest accumulation. However, the accumulation of toxic elements in omnivorous fish was higher than in carnivorous fish. The individual pollution load index indicated that sediment was very polluted with As and Pb, but based on the combined ecological indexes, low elemental sediment pollution in the Espinillo Lake was revealed.

Distribution and accumulation of major and trace elements in water, sediment, and fishes from protected areas of the Atlantic Rainforest.

Environmental pollution affects the quality of the natural environment where major and trace elements have been commonly found to accumulate in biotic and abiotic matrices. The purposes of this research were (1) to assess the accumulation and distribution of 24 major and trace elements in water, sediments, and muscle and gills of ten native fishes from two natural areas with different degree of protection in the Atlantic Rainforest, (2) to discuss potential origin of the elements related to the land use, and (3) to assess the human health risk for water and muscle fish consumption in general and fisher populations. Major and trace elements were determined by inductively coupled plasma mass spectrometry. Concentrations of Ag, Cu, and Se in water and Cr, Cu, Hg, Mn, Ni, and Zn in sediment were higher than the international guidelines for the aquatic biota protection. Muscle Cr, Cu, Ni, Pb, Hg, and Zn from several species (both studied areas) were above guidelines for human consumption. The bioaccumulation factor (< 6936) was higher in gills than in muscle, and indicated that Andromakhe saguazu, Andromakhe paris, Gymnogeophagus lipokarenos, and Steindachnerina biornata were macroconcentrators of Zn, and Australoheros ykeregua, G. lipokarenos, and Hemiancistrus fuliginosus were macroconcentrators of Se and Sr. The hazard index and target hazard quotient indicated that there is no risk from chronic consumption of water or fish. The results show the need to reduce the entry of pollutants into streams, paying special attention to reducing runoff in deforested areas.

Bioaccumulation of 10 trace elements in juvenile fishes of the Lower Paraná River, Argentina: implications associated with essential fish growing habitat.

This study assessed the concentration, bioconcentration, and bioaccumulation of As, Cd, Co, Cr, Cu, Mg, Mn, Ni, Pb, and Zn in juvenile fishes (Acestrorynchus pantaneiro, Brycon orbygnianus, Cyphocharax voga, Megaleporinus obtusidens, Odontesthes bonariensis, Pimelodus maculatus, Prochilodus lineatus, Salminus brasiliensis, and Schizodon borelli) in the Lower Paraná River (Argentina), the most extensive floodplain from the Plata Basin. The floodplain is crucial for the reproduction and growth of various species such as P. lineatus, M. obtusidens, and S. brasiliensis, which complete their life cycle in this environment. In total, 90 individuals were sampled for nitrogen stable isotope, and trace element analysis in muscle tissue, water, and sediment was analyzed. The results show that all the studied species bioaccumulate Cr, Mg, Ni, and Zn. In particular, B. orbygnianus and P. maculatus presented the highest bioaccumulation factor for Cr. A biodilution of Co through the food chain was observed. No positive correlation was found between element concentration and trophic level, but we observed significant differences between trophic guilds (herbivorous, omnivorous, and carnivorous). Our findings suggest that feeding habits determine trace element concentrations. To establish differential behavior between different species within the aquatic web further studies are necessary, particularly in the floodplain of the Paraná, which is a crucial nursery area for most commercially important fishes from the Plata Basin. Graphical abstract.

Metals and metalloids in a first order stream of the Atlantic rainforest: abiotic matrices, bioaccumulation in fishes and human health risk assessment.

BACKGROUND AND AIM: Metals and metalloids have been found in several streams and rivers from the Atlantic Rainforest (ARF), one of the world´s leading biodiversity hotspot, which may represent a risk for environmental and human health. The aims of this study were: 1) to evaluate the accumulation and distribution of 24 trace elements in water, sediments and fish tissues (muscle and gills) of sixteen species from the Atlantic Rainforest, 2) to explore bioaccumulation patterns in fish tissues and abiotic matrices, and 3) to assess the impact of metal and metalloids on the human health from water and fish consumption. METHODS: Water, sediments and fish samples were collected from Ramos Stream (Misiones Province, Argentina). The concentrations of Ag, Al, As, Ba, Be, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, Li, Mg, Mn, Ni, Pb, Se, Sr, Ti, U, V and Zn were determined by Quadrupole Inductively Coupled Plasma Mass Spectrometry. Bioaccumulation factors (BAFs) were used to evaluate bioaccumulation of metals and metalloids in relation to water and sediment. The Hazard Quotient (HQ), Hazard Index (HI) and Target Hazard Quotient (THQ, general and fisherman populations) were calculated to assess the non-carcinogenic human health risk from water and fish consumption. RESULTS: The concentrations of several elements in water and sediment were higher than the international guidelines for aquatic biota protection. Levels of As, Pb and Zn in muscle and gills were above national and international guidelines for human consumption. The bioaccumulation factors ranged from 749 to 13,029 being higher in gills than in muscle. The HQ and HI ranged from 0.001 to 0.015. The THQ for each element and total THQ values were lower than 0.1. CONCLUSION: Bioaccumulation factor suggests that several species have a moderate capacity to incorporate some metals and metalloids from the abiotic matrices. According to the HI and THQ values found, there is no risk to human health from consumption of water and fish.