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1.
Int J Mol Sci ; 22(6)2021 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-33803585

RESUMEN

Methylmercury (MeHg) toxicity is a major environmental concern. In the aquatic reservoir, MeHg bioaccumulates along the food chain until it is consumed by riverine populations. There has been much interest in the neurotoxicity of MeHg due to recent environmental disasters. Studies have also addressed the implications of long-term MeHg exposure for humans. The central nervous system is particularly susceptible to the deleterious effects of MeHg, as evidenced by clinical symptoms and histopathological changes in poisoned humans. In vitro and in vivo studies have been crucial in deciphering the molecular mechanisms underlying MeHg-induced neurotoxicity. A collection of cellular and molecular alterations including cytokine release, oxidative stress, mitochondrial dysfunction, Ca2+ and glutamate dyshomeostasis, and cell death mechanisms are important consequences of brain cells exposure to MeHg. The purpose of this review is to organize an overview of the mercury cycle and MeHg poisoning events and to summarize data from cellular, animal, and human studies focusing on MeHg effects in neurons and glial cells. This review proposes an up-to-date compendium that will serve as a starting point for further studies and a consultation reference of published studies.


Asunto(s)
Encéfalo/patología , Inflamación/patología , Compuestos de Metilmercurio/toxicidad , Síndromes de Neurotoxicidad/patología , Animales , Bioacumulación , Encéfalo/efectos de los fármacos , Humanos , Compuestos de Metilmercurio/farmacocinética , Microbiota/efectos de los fármacos , Síndromes de Neurotoxicidad/microbiología , Síndromes de Neurotoxicidad/prevención & control , Síndromes de Neurotoxicidad/terapia
2.
Artículo en Inglés | MEDLINE | ID: mdl-33805997

RESUMEN

The objective of this commentary is to promote the use of bivalves as biomonitors, which is a part of the continual efforts of the International Mussel Watch. This commentary is an additional discussion on "Bivalve mollusks in metal pollution studies: From bioaccumulation to biomonitoring" by Zuykov et al., published in Chemosphere 93, 201-208. The present discussion can serve as a platform for further insights to provide new thoughts and novel ideas on how to make better use of bivalves in biomonitoring studies. The certainty of better and more extensive applications of mollusks in environmental monitoring in the future is almost confirmed but more studies are urgently needed. With all the reported studies using bivalves as biomonitors of heavy metal pollution, the effectiveness of using Mussel Watch is beyond any reasonable doubts. The challenge is the development of more accurate methodologies for of heavy metal data interpretation, and the precision of the biomonitoring studies using bivalves as biomonitors, whether in coastal or freshwater ecosystems. Lastly, inclusion of human health risk assessment of heavy metals in commercial bivalves would make the research papers of high public interest.


Asunto(s)
Bivalvos , Metales Pesados , Contaminantes Químicos del Agua , Animales , Bioacumulación , Monitoreo Biológico , Ecosistema , Monitoreo del Ambiente , Humanos , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis
3.
Ecotoxicol Environ Saf ; 214: 112099, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33714139

RESUMEN

Although fish are widely confirmed to be susceptible to heavy metals (HMs) contamination in sediments, this bioconversion haven't been detailed. This is especially the case in karst areas, where HMs are less stably retained in the sediments and are more bioavailable. Therefore, we surveyed representative karst rivers in Liuzhou, China, in order to study the relationship between the speciations of seven HMs in the sediments with their bioaccumulation in wild fish. The results showed that the HMs in sediments are all below their permissible exposure limit (PEL), but Cd and Zn are significantly higher than soil basline. Most HMs are in residual fraction, while their exchangeable fractions are present in extremely low proportions. The concentration of Zn, Cr and Cd in some fish are above their maximum recommended limit (MRL). The concentrations of most of the HMs in the fish are significantly correlated with the levels in the sediments and given the higher correlation coefficients for their carbonate-bound phase, this phase can be seen to play a critical role in HMs bioconversion. However, the presence of this phase in low proportions enables other phases, especially oxidizable form, to play a greater role in HMs bioaccumulation. Apart from Do, HMs in the fish samples are significantly correlated with multiple environmental factors, demonstrating environmental fluctuations can manipulate HMs bioconversion from sediments; however, their significance depend heavily on the proportion of particular species. HMs in reducible and oxidizable fraction are more important in regulating, rather than promoting, their bioconversion during environmental fluctuations. Fluctuations in EC, TDS and pH can increase the impacts of HMs in carbonate-bound fraction on their bioconversion. Given the higher background values of EC and TDS and lower pH values during the monsoon period, careful attention should be paid to the increased bioconversion of HMs in karst rivers during this season.


Asunto(s)
Monitoreo del Ambiente , Peces/fisiología , Metales Pesados/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Bioacumulación , China , Sedimentos Geológicos , Metales Pesados/análisis , Medición de Riesgo , Ríos , Estaciones del Año , Suelo , Contaminantes Químicos del Agua/análisis
4.
Sci Total Environ ; 768: 144430, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33736337

RESUMEN

Although hepatic metabolism of hexabromocyclododecanes (HBCDs) played critical roles in the selective bioaccumulation of HBCDs in humans, the hepatic metabolism patterns of its enantiomers remained ambiguous. Aiming to elucidate the mechanism on hepatic metabolism of hexabromocyclododecanes (HBCDs) enantiomers, the enantiomers ((+)-α-HBCD, (-)-α-HBCD, (+)-γ-HBCD, and (-)-γ-HBCD), the diastereoisomers (α-, ß-, and γ-HBCDs) and the mixed of α- and γ-HBCDs were incubated with human HepG2 cell under different exposure levels in the present study. The clearance percentages ranked as γ-HBCD enantiomers >ß-HBCD enantiomers >α-HBCD enantiomers at the same exposure levels. The clearance percentages of (+)- and (-)-α-HBCDs increased when cells were exposed to racemic α-HBCD and the mixture of racemic α- and γ-HBCDs (p < 0.05). (-)-γ-HBCD was more resistant to human hepatic metabolism than (+)-γ-HBCD, leading to the enantiomer fractions (EFs) of γ-HBCD lower than 0.50. (-)-α-HBCD was slightly more metabolized when independently exposed to α-HBCD, while (+)-α-HBCD was more preferentially metabolized after exposure to α- and γ-HBCD mixtures. Hydroxylation and debromination HBCD metabolites were identified. In addition, the different EFs of HBCDs in cells and mediums suggested the selective transfer of chiral HBCDs and HBCD metabolites through the cell membrane. This study provided new insight into the enantiomer-selective metabolism of HBCDs.


Asunto(s)
Retardadores de Llama , Hidrocarburos Bromados , Bioacumulación , Células Hep G2 , Humanos , Estereoisomerismo
5.
Huan Jing Ke Xue ; 42(4): 2031-2039, 2021 Apr 08.
Artículo en Chino | MEDLINE | ID: mdl-33742838

RESUMEN

The Cd bioaccumulation factor (BCF) of crops is affected by many aspects. In order to clarify the differences in the Cd bioaccumulation factor characteristics of different crops under field conditions and the influence of soil properties, point-to-point samples of soil and crop grains were collected during crop harvesting on plots with varying pollution levels in the primary production areas of rice, wheat, and maize in China. The characteristics of the Cd bioaccumulation factors of rice, wheat, summer maize, and spring maize and the effects of soil properties on the Cd bioaccumulation factors of different crops were studied, and the quantitative relationship between the Cd bioaccumulation factors and soil properties was established through multiple regression equations. The results revealed that the average BCF values of Cd in rice, wheat, summer maize, and spring maize were 0.915, 0.155, 0.113, and 0.102, respectively, with the Cd content in the field soil of 0.15-2.66 mg·kg-1. Rice is significantly higher than wheat and maize, and spring maize has the lowest Cd bioaccumulation factor. The Cd content in the soil is extremely negatively correlated with the BCF of wheat, summer maize, and spring maize. The relationship between soil organic matter (SOM) and the BCF of wheat and summer maize demonstrated a significant negative correlation. The soil pH and cation exchange capacity (CEC) also affect the BCF of crops. Introducing the soil Cd content, pH, SOM, CEC, and other factors, the Cd bioaccumulation factor prediction equations of rice, wheat, summer maize, and spring maize were established. The correlation coefficients of the BCF prediction equations for rice, wheat, summer maize, and spring maize are 0.423*, 0.796**, 0.826**, and 0.551**, respectively. The above models reached significant or extremely significant levels, which can better predict the BCF value of different crops under varying soil conditions.


Asunto(s)
Oryza , Contaminantes del Suelo , Bioacumulación , Cadmio/análisis , China , Suelo , Contaminantes del Suelo/análisis
6.
Huan Jing Ke Xue ; 42(3): 1166-1176, 2021 Mar 08.
Artículo en Chino | MEDLINE | ID: mdl-33742913

RESUMEN

A total of 86 soil samples, 86 corn kernel samples, 50 tailings samples, and 33 ore rock samples were collected in reclaimed land and surrounding areas of typical vanadium-titanium magnetite tailings located in the Chengde Central Region and analyzed for 14 elements (P, Fe, Cu, Ni, Cd, Cr, Pb, Zn, Hg, Ti, Mn, and Mo) and speciation of heavy metals. This study investigated the bioaccumulation and translocation characteristics of heavy metals in a soil-maize system based on a descriptive statistical analysis, a geological accumulative index, bioconcentration factors, and a redundancy analysis. The results showed that the average accumulation index of surface soil followed an order of P > Cu > Fe2O3 > Cr > Ti > V > Ni > Mn > Cd > Zn > Mo > As > Pb > Hg, while the accumulation level of heavy metals was generally categorized as either no accumulation or moderate accumulation. Compared to China's soil environmental quality standard risk screening values (GB15618-2018), the over-standard rates of Cr and Cu were 2.32% and 1.16%, respectively. The content of Fe, Ti, As, Pb, and Mn in the corn kernels of the tailings and surrounding areas was relatively high, and the content of Mo, Ni, Cu, Zn, Cd, and Cr in the control area was relatively high. The over-standard rates of Ni, Zn, and Cu in the corn kernels were 13.61%, 13.23%, and 5.17% respectively, according to China's national food safety standard limits for contaminants in food (GB 2762-2017). The bioconcentration factors of Fe, Ti, As, Pb, and Mn in the corn kernels of the tailings and the surrounding areas were relatively higher, while the bioconcentration factors of Mo, Ni, Cu, Zn, Cd, and Cr were lower than in control area. The bioactive components of Cd accounted for 50.17%, which was the highest, followed by Ni, Zn, and Cu with average ratios of 13.61%, 13.23%, and 5.17%, respectively. Compared to the control area, the Pb, As and Hg elements in the soil samples of the reclaimed land showed a lower total amount but a higher bioavailability content and soil pH value, while the Cu and Hg elements showed a higher total amount but lower bioavailability content and soil pH value. These differences in total heavy metal concentrations, bioavailability amounts, and soil pH values made the bioconcentration intensity of As and Pb in the tailings reservoir and surrounding area relatively higher. When studying the ecological risk of heavy metal pollution or determining the remediation target value of reclaimed land in a mine tailings reservoir and the soil around the mine area, the bioavailable state limit of heavy metals should be should be taken into account as the evaluation standard.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Bioacumulación , China , Monitoreo del Ambiente , Óxido Ferrosoférrico , Metales Pesados/análisis , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisis , Titanio , Vanadio , Zea mays
7.
Ecotoxicol Environ Saf ; 215: 112176, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33780780

RESUMEN

Both tetrabromobisphenol A (TBBPA) and titanium dioxide nanoparticle (TiO2 NP) have widespread commercial applications, resulting in their ubiquitous co-presence in the environment and biota. Although environmental chemicals exist as mixtures, toxicity studies are nearly always conducted with single chemicals. Few studies explore potential interactions of different chemical mixtures. In this study, we employ the sensitive developing nerve system in zebrafish to assess the neurotoxicity of TBBPA/TiO2 NP mixtures. Specifically, zebrafish embryos were exposed to solvent control (0.1% DMSO), 2 µM TBBPA, 0.1 mg/L TiO2 NP, and their mixture from 8 to 120 h post fertilization (hpf), and motor/social behavioral assessments were conducted on embryos/larvae at different developmental stages. Our results showed that TBBPA/TiO2 NP single or co-exposures increased spontaneous movement, decreased touch response and swim speed, and affected social behaviors of light/dark preference, shoaling, mirror attack and social contact. In particular, many of these phenotypes were manifested with higher magnitude of changes from the mixture exposure. These behavioral deficits were also accompanied with increased cell death in olfactory region and neuromasts in the lateral line system, increased ROS in gallbladder, pancreas, liver, and intestine, as well as increased lipid peroxidation and decreased ATP levels in whole larval tissue homogenates. Further, genes coding for key cell apoptosis marker and antioxidant enzyme were significantly upregulated by these two chemicals, in particular to their mixture. Interestingly, the co-presence of TBBPA also increased the mean particle size of TiO2 NP in the exposure solutions and the TiO2 NP content in larval tissue. Together, our analysis suggests that TBBPA/TiO2 NP induced behavioral changes may be due to physical accumulation of these two chemicals in the target organs, and TiO2 NP may serve as carriers for increased accumulation of TBBPA. To conclude, we demonstrated that TBBPA/TiO2 NP together cause increased bioaccumulation of TiO2, and heightened responses in behavior, cell apoptosis and oxidative stress. Our findings also highlight the importance of toxicity assessment using chemical mixtures.


Asunto(s)
Nanopartículas/toxicidad , Bifenilos Polibrominados/toxicidad , Titanio/toxicidad , Contaminantes Químicos del Agua/toxicidad , Pez Cebra/fisiología , Animales , Antioxidantes/metabolismo , Apoptosis , Bioacumulación , Larva/metabolismo , Peroxidación de Lípido , Hígado/metabolismo , Estrés Oxidativo , Conducta Social
8.
Bull Environ Contam Toxicol ; 106(5): 799-804, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33738576

RESUMEN

The objective of the study was to assess the heavy metal contamination in excreta of the Baya Weaver Bird (Ploceus philippinus). Samples were collected from nesting colony sites present in three districts viz. Ludhiana (location I), Ropar (location II) and Ferozepur (location III) falling in Central plain zone, Undulating plain zone and Western plain zone of Punjab respectively. In dry excreta samples fifteen elements were detected through ICAP-AES; As, Pb, Cd, Cr were toxic heavy metals and B, Fe, Cu, Ni, Zn, Mn, Mg, Ca, P, S, Na were essential elements. Toxic heavy metals viz. As (1.88-2.10 ppm), Pb (2.70- 5.25 ppm) and Cr (13.30-23.78 ppm) were found above normal range in excreta collected from studied locations. Statistical analysis showed significant difference among heavy metals and locations which signifies the bioaccumulation of different metals at different locations in excreta of Baya Weaver Bird due to different type of contaminations at studied locations.


Asunto(s)
Metales Pesados , Passeriformes , Animales , Bioacumulación , Monitoreo del Ambiente , Metales Pesados/análisis
9.
Mar Pollut Bull ; 166: 112209, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33714036

RESUMEN

This is the first investigation of the potential for using Cymodocea nodosa to biomonitor trace element (TE) contamination in Marchica lagoon (Morocco), a Mediterranean pollution hotspot. We measured concentrations of seven TEs in seagrass tissues (leaf-rhizome-root) and sediments. Single and multi-element indices confirmed that sediments near illegal discharges were heavily polluted and we predicted risks of frequent adverse biological effects in these areas. Four of the TEs increased concentrations in C. nodosa leaf and root along sediment pollution gradient. Leaves and roots were both good indicators of Cu and Cd contamination in sediment, whereas leaves were the best indicator of Zn and roots for Pb. This seagrass was not a bioindicator of Al, Cr and Ni contamination. These results show the bioaccumulation patterns of TEs in C. nodosa, and can be used to design biomonitoring programs.


Asunto(s)
Metales Pesados , Oligoelementos , Contaminantes Químicos del Agua , Bioacumulación , Monitoreo Biológico , Monitoreo del Ambiente , Sedimentos Geológicos , Metales Pesados/análisis , Marruecos , Oligoelementos/análisis , Contaminantes Químicos del Agua/análisis
10.
Sci Total Environ ; 776: 145731, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33647664

RESUMEN

In this study, 17 legacy and emerging PFASs were investigated in soil and plant leaves near a valley-type landfill, which has been in operation for over 20 years. ΣPFASs concentrations ranged from 5.31 to 108 ng/g dw and 11.9 to 115 ng/g dw in the soil and leaf samples, respectively, and perfluorobutanoic acid (PFBA) was dominant in both soil and leaves. The concentrations of hexafluoropropylene oxide dimer acid (HFPO-DA), 6:2 chlorinated polyfluorinated ether sulfonic acid (F-53B) and 6:2 fluorotelomer sulfonic acid (6:2 FTS) were significantly higher than those of legacy PFOA and PFOS, indicating emerging alternatives were widely applied in the region. The integrated approach of PCA analysis, field investigation of relevant industrial activities in the study area, along with the Unmix model analysis quantitatively revealed that factories producing consumer products and the landfill were the major sources of PFASs in soil, accounting for 57% of total PFASs detected. Bioaccumulation factors (BAFs) of ΣPFASs in leaves varied from 0.37 to 8.59, and higher BAFs were found in camphor leaves. The log10BAFs in all plant leaves showed a linear decrease with increasing carbon chain lengths for individual PFCAs (C4-C8). The BAF values of HFPO-DA, F-53B and 6:2 FTS were 0.01-3.39, 0.04-6.15 and 0.01-6.33, respectively. The human health risk assessment of EDIs showed a decreasing trend with the increasing carbon chain lengths of PFCAs (C4-C9), and the PFASs EDI indicated further study on the human health risk via vegetable consumption be warranted.


Asunto(s)
Ácidos Alcanesulfónicos , Fluorocarburos , Contaminantes Químicos del Agua , Bioacumulación , China , Monitoreo del Ambiente , Fluorocarburos/análisis , Humanos , Hojas de la Planta/química , Suelo , Instalaciones de Eliminación de Residuos , Contaminantes Químicos del Agua/análisis
11.
Environ Monit Assess ; 193(4): 167, 2021 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-33677702

RESUMEN

Role of spring and neap tides on metal bioavailability and bioaccumulation in edible biota was studied in the Zuari Estuary. Moderate to very high range of contamination factor for Fe, Mn, Cr, Zn, Cu, Cd, and Pb at one or more stations and tides suggesting their anthropogenic origin. The anthropogenic input of metals was supported by pollution load index. Relatively high bioavailable concentration of Fe, Mn, Cr, Zn, Cu, Cd, and Pb indicated their toxicity to biota. Total metal concentration, viz., Fe, Mn, Cr, Zn, Cu and Cd, and bioavailable content Mn, Cd, and Pb were higher during spring tide than neap tide at one or more stations which revealed their low mobility under flooded conditions. The above observation was well supported by higher concentration of Fe, Mn, Cr, Zn, Cu, and Pb in Polymesoda erosa at the middle estuary during neap tide than subsequent spring tide. Further, an increase in concentration of metals bound to certain bioavailable fractions toward the surface of the cores revealed their possible bioavailability to the biota with changes in the physicochemical properties of the Zuari estuary. Biota sediment accumulation factor revealed macro level accumulation of Cd and suggested its toxicity to marine biota.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Animales , Bioacumulación , Disponibilidad Biológica , Biota , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis
12.
Environ Int ; 152: 106500, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33714869

RESUMEN

Atrazine, a potent herbicide for weeds removal during the growing season, has been widely used in China. It is known to be distributed in aquatic ecosystems with a long half-life, thus presenting a potential risk to species and consumers. This study analyzed the concentrations of degraded atrazine residues in marine organisms (N = 129) including 3 species of mollusks, 2 species of crustaceans, and 15 species of fish from a semi-enclosed bay, Jiaozhou Bay (JZB), adjacent to the Northwest Pacific Ocean in China. The corresponding trophic magnification factors (TMF), bioaccumulation factors (BCFs), and subsequent risks to final consumers were also determined. The results showed an average atrazine concentration of (0.301 ± 0.03) ng g-1 and (0.305 ± 0.04) ng g-1 in fish and invertebrates, respectively. The BCFs were (5.23 ± 1.75) L kg-1 and (5.81 ± 1.31) L kg-1 for fish and invertebrates, respectively. Atrazine was significantly bio-diluted in JZB through the sampled marine organisms with increasing trophic levels, with a TMF value below 1 (P < 0.01). An analysis of the species sensitivity distribution (SSD) predicted that<0.02% of species were exposed to a dissolved concentration of atrazine (57.88 ng L-1) that would lead to detrimental effects, while risk quotients predicted low long-term risks for species in the bay. Finally, people with a diet limited to species from JZB were found to face no associated health risk due to a significantly small daily intake and target hazard quotient of atrazine. The corresponding non-carcinogenic effect showed no significant risk from seafood consumption.


Asunto(s)
Herbicidas , Contaminantes Químicos del Agua , Animales , Organismos Acuáticos , Bioacumulación , China , Ecosistema , Monitoreo del Ambiente , Peces , Cadena Alimentaria , Herbicidas/toxicidad , Humanos , Océano Pacífico , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
13.
Arch Environ Contam Toxicol ; 80(3): 579-586, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33730174

RESUMEN

The brominated flame retardant bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH) is used widely in consumer items including polyurethane foam used in furniture. Information on its bioaccumulation in aquatic species is limited. In the current study, sediment bioaccumulation tests with the oligochaete Lumbriculus variegatus were performed on a spiked natural sediment equilibrated for 14.5 months. Analysis showed the TBPH used to spike the sediment contained a small amount (0.046% by mass) of mono-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBMEHP), a potential biotransformation product of the parent chemical. Steady-state biota-sediment accumulation factors (BSAFs) of 0.254 and 1.50 (kg organic carbon/kg lipid) were derived for TBPH and TBMEHP, respectively. TBPH had biphasic elimination behavior where 94% of the body burden was depleted within the first 12 h of elimination (i.e., half-life of 1.2 h or less) and the remaining 6% eliminated very slowly thereafter (half-life of 15 days). There was little evidence for biotransformation of either chemical by L. variegatus. This investigation confirms the extremely hydrophobic behavior of TBPH and its impact on its bioavailability.


Asunto(s)
Retardadores de Llama , Oligoquetos , Ácidos Ftálicos , Animales , Bioacumulación , Disponibilidad Biológica , Retardadores de Llama/análisis , Sedimentos Geológicos
14.
Ecotoxicology ; 30(4): 643-657, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33754232

RESUMEN

The aim of this study was to assess whether possible metal contamination in the sediment of the nests of giant Amazon river turtle, Podocnemis expansa, could contaminate eggs and hatchlings, triggering genotoxic damage. Therefore, sediments of P. expansa nests from two sites in the Brazilian Amazon were evaluated, with the first being collected at Araguaia River and the second at Crixás-Açu River. Newly hatched offspring, eggs, and sediments were collected from the beaches of these two rivers and the quantification of metals (Al, Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn) was carried out by atomic absorption spectroscopy. All targeted metals were found in both sediment and P. expansa biological samples collected on the beaches presenting higher concentrations in the sediment of Crixás-Açu River. Metals found in the eggshells before nesting and in the egg contents were maternally transferred. Moreover, augmented concentration of metals led by metal transfer from the nests sediments were detected in the eggshells after nesting (ENH) and in the newly hatched offspring (H). Probably this metal relocation to the newly hatchlings augmented the frequency of micronuclei in their blood, presenting 15.25‰ in hatchling found in Crixás-Açu River beaches and 10‰ in newly hatched animals from Araguaia River beaches. These results indicate the occurrence of maternal transfer of metals (essential or not) to the eggs in testudines as well as a transference from the sediments to the nesting eggs, triggering genotoxic effects on the hatchlings.


Asunto(s)
Metales Pesados , Tortugas , Contaminantes Químicos del Agua , Animales , Bioacumulación , Brasil , Daño del ADN , Monitoreo del Ambiente , Sedimentos Geológicos , Metales Pesados/análisis , Ríos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
15.
Environ Pollut ; 278: 116855, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33706244

RESUMEN

The impact of oil exploration and production activities on the environment of sub-saharan African countries is not well studied. This study aimed at determining concentrations, sources, and bioaccumulation of 13 polycyclic aromatic hydrocarbons (PAHs) in sediments and fish from the White Nile near Melut oil fields, South Sudan. The study also assessed the ecological and human health risk associated with PAHs in this aquatic system. Total (∑13) PAH concentrations ranged from 566 to 674 ng g-1dry weight (dw) in sediments, while those in fish were 191-1143 ng g-1 wet weight (ww). ∑13PAH concentrations were significantly higher in C. gariepinus than in other fish species. Low molecular weight PAHs (LPAHs) dominated the profile of PAHs in sediments (constituted 95% of ∑13PAHs) and fish (97% of ∑13PAHs). Compared to Sediment Quality Guidelines of the United States Oceanic and Atmospheric Administration, the levels of LPAHs in this study were all above the threshold effect limits, but below the probable effect level, while those of high molecular weight PAHs (HPAHs) were all below the lowest effect levels. The carcinogenic potency equivalent concentrations of PAHs in L. niloticus and C. gariepinus were above the US EPA screening level; suggesting consumption of these species could adversely affect human health. Biota-sediment accumulation factor values (range: 0.006-3.816 g OC g-1 lipid) for PAHs showed high bioaccumulation of LPAHs in fish muscle, and that bioaccumulation decreased with increase in hydrophobicity of the compounds. This is possibly because LPAHs have higher aqueous solubilities which increases their bioavailability through water-gill transfers compared to HPAHs. Profiles of PAHs in the White Nile environment indicate predominant contribution from petrogenic sources, which could be attributed to presence of crude oil reservoirs and oil production operations. More research into the levels of other environmental pollutants in the oil-rich area is recommended.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , África Oriental , Animales , Bioacumulación , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Hidrocarburos Policíclicos Aromáticos/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis
16.
Ecotoxicol Environ Saf ; 215: 112122, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33725489

RESUMEN

The human ingestion of mercury (Hg) from sea food is of big concern worldwide due to adverse health effects, and more specifically if shark consumption constitutes a regular part of the human diet. In this study, the total mercury (THg) concentration in muscle tissue were determined in six sympatric shark species found in a fishing vessel seized in the Galapagos Marine Reserve in 2017. The THg concentrations in shark muscle samples (n = 73) varied from 0.73 mg kg-1 in bigeye thresher sharks (Alopias superciliosus) to 8.29 mg kg-1 in silky sharks (Carcharhinus falciformis). A typical pattern of Hg bioaccumulation was observed for all shark species, with significant correlation between THg concentration and shark size for bigeye thresher sharks, pelagic thresher sharks (Alopias pelagicus) and silky sharks. Regarding human health concerns, the THg mean concentration exceeded the maximum weekly intake fish serving in all the studied species. Mass-Dependent Fractionation (MDF, δ202Hg values) and Mass-Independent Fractionation (MIF, Δ199Hg values) of Hg in whitetip sharks (Carcharhinus longimanus) and silky sharks, ranged from 0.70‰ to 1.08‰, and from 1.97‰ to 2.89‰, respectively. These high values suggest that both species are feeding in the epipelagic zone (i.e. upper 200 m of the water column). While, blue sharks (Prionace glauca), scalloped hammerhead sharks (Shyrna lewini) and thresher sharks were characterized by lower Δ199Hg and δ202Hg values, indicating that these species may focus their foraging behavior on prey of mesopelagic zone (i.e. between 200 and 1000 m depth). In conclusion, the determination of THg concentration provides straight-forward evidence of the human health risks associated with shark consumption, while mercury isotopic compositions constitute a powerful tool to trace the foraging strategies of these marine predators. CAPSULE: A double approach combining Hg concentrations with stable isotopes ratios allowed to assess ontogeny in common shark species in the area of the Galapagos Marine Reserve and the human health risks concern associated to their consumption.


Asunto(s)
Mercurio/metabolismo , Tiburones/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Bioacumulación , Monitoreo del Ambiente/métodos , Conducta Alimentaria , Humanos , Isótopos , Mercurio/análisis , Isótopos de Mercurio , Músculos/química , Alimentos Marinos , Tiburones/fisiología , Contaminantes Químicos del Agua/análisis
17.
Ecotoxicol Environ Saf ; 213: 111983, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33582413

RESUMEN

Methyl siloxanes are identified as emerging persistent toxic compounds and the ecological environment risks of these compounds have been caused of great concern worldwide. In this study, the concentrations of methyl siloxanes were reported in dissolved water and crucian carp around a methyl siloxane production factory located in Liaoning Province, Northeast China. D4, D5, D6, D7, L4, L5 and L6 were detectable both in dissolved water and crucian carp. The total concentrations of 7 methyl siloxanes (Σ7MS) were 14 ± 6.3 ng/L in dissolved water and 43 ± 22 ng/g ww in crucian carp, respectively. D5 has the highest concentration both in dissolved water (5.5 ± 3.5 ng/L) and crucian carp (17 ± 11 ng/g ww). Based on the monitoring values, bioaccumulation factor (BAF) of these compounds were calculated. Significant bioaccumulation potential was observed for D4 (BAF = 5900 ± 3500 L/kg) based on the bioaccumulation criteria suggested by USEPA and EU (BAF > 5000 L/kg). To our understanding, this is the first report of BAF values of methyl siloxane in field study, which will provide important support for further assessment of bioaccumulation of these compounds.


Asunto(s)
Carpas/metabolismo , Siloxanos/análisis , Siloxanos/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Bioacumulación , China , Monitoreo del Ambiente , Carpa Dorada/metabolismo , Contaminantes Químicos del Agua/análisis
18.
Ecotoxicol Environ Saf ; 213: 112017, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33582414

RESUMEN

The distribution of hydrophobic organic contaminants (HOCs) in eutrophic ecosystems has been widely studied, but how phytoplankton blooms affect their occurrence and benthic bioaccumulation is poorly understood. To fill this knowledge gap, the biological pump effects of phytoplankton on the fate of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in sediments and benthos (Corbicula fluminea) from Lake Taihu, a hypereutrophic lake in China, were identified. The spatial-temporal distribution of HOCs suggests that higher phytoplankton biomass, coupled with sediment organic matter (SOM) content, greatly increased the concentration of HOCs in sediments in both winter and summer seasons. This could be attributed to the biological pump effects sequestering more HOCs from water to sediments with settling phytoplankton, especially during the summer. The biological pump effects further promoted the uptake of sediment-bound HOCs by benthos. The significant positive relationships between concentrations of HOCs in sediments and benthos were observed during the winter dormancy phase of benthos. Furthermore, the benthic bioaccumulation of HOCs could be strengthened by phytoplankton, due to their contribution to SOM and the following increased bioavailability of HOCs in sediments. Further research is needed to elucidate the phytoplankton biological pump effects on the fate of HOCs in benthic food chain, especially for hypereutrophic waters.


Asunto(s)
Monitoreo del Ambiente , Hidrocarburos Clorados/análisis , Contaminantes Químicos del Agua/análisis , Bioacumulación , Biomasa , Ecosistema , Cadena Alimentaria , Sedimentos Geológicos/química , Interacciones Hidrofóbicas e Hidrofílicas , Lagos/química , Proteínas de Transporte de Membrana , Plaguicidas/análisis , Fitoplancton , Hidrocarburos Policíclicos Aromáticos/análisis , Estaciones del Año
19.
Aquat Toxicol ; 233: 105772, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33618324

RESUMEN

Besides the adverse biological effects induced by microplastics (MPs), the effects associated with sorption of ambient pollutants on MPs are considered as an emerging environmental problem as MPs act as a mediator of pollutants. The present study examines the combined effects of nano(micro)plastics (NMPs) and arsenic (As) by exposing the marine rotifer Brachionus plicatilis to MP particles at the micro-scale (6 µm) and nano-scale (nanoplastics, NPs) (50 nm) along with As. In vivo toxicity, bioaccumulation, and biochemical reactions were used to examine the effects of combined exposure. The results of in vivo experiments showed that As toxicity increased with NP exposure, whereas toxicity was alleviated by MPs, indicating a different mode of action between NPs and MPs in combination with As. The highest level of As bioaccumulation was detected in NP + As groups, and followed by MP + As and As-only exposure groups, whereas no significant difference between groups was shown for As metabolites. In addition, the activity of several ATP-binding cassette proteins that confer multixenobiotic resistance, which is responsible for efflux of As, was activated by As but significantly inhibited by NP exposure, supporting the findings of in vivo experiments. Our results show that the effects of combining exposure to As with NP and MPs differ depending on particle size and provide an in-depth understanding of both environmental pollutants.


Asunto(s)
Arsénico/toxicidad , Microplásticos/toxicidad , Nanopartículas/toxicidad , Rotíferos/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Arsénico/metabolismo , Bioacumulación , Disponibilidad Biológica , Microplásticos/metabolismo , Modelos Teóricos , Nanopartículas/metabolismo , Rotíferos/metabolismo , Natación , Contaminantes Químicos del Agua/metabolismo
20.
Food Chem ; 349: 129137, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33556727

RESUMEN

Contamination of perfluoroalkyl substances (PFASs) in agricultural products have attracted more and more attentions recently. In this review, relationship between PFASs and vegetables is summarized comprehensively. PFASs could transfer to cultivation soils by irrigation water, bio-amended soil, and atmospheric deposition mainly from industrial emissions. Carbon chain length of PFASs, species of vegetables and so on are key factors for PFASs migration and bioaccumulation in soils, plants and vegetables. Studies on food risk assessment of PFOA and PFOS show low consumption risk for most vegetables, however researches on other substances are lacking. In the future, we need to pay more attention on novel pollution pathway in cultivation, traceability research for considerable contamination, dietary exposure levels for different vegetables and more substances, as well as more exact and scientific food risk assessments. Additionally, effective means for PFASs adsorption in soil and removal from soil are also expected.


Asunto(s)
Bioacumulación , Fluorocarburos/metabolismo , Contaminación de Alimentos/análisis , Verduras/metabolismo , Alquilación , Fluorocarburos/química , Medición de Riesgo
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