Application of Focused Ultrasound-Assisted Extraction to the Determination of Persistent Organic Pollutants (POPs) in Soil Samples

Persistent organic pollutants in the olive ridley turtle (Lepidochelys olivacea) during the nesting stage in the "La Escobilla" Sanctuary, Oaxaca, Mexico

Persistent organic pollutants (POPs) are chemical substances widely distributed in the environment by the runoff from anthropic activities and can be distributed and bioaccumulated or biomagnified in the environment, affecting the health of organisms. The sea turtle, Lepidochelys olivacea, is a long-lived organism, with migratory habits and feeding behaviors that allow exposure to various pollutants. This work aimed to determine long-term exposure to POPs in adult olive ridley turtles (L. olivacea), sampled during the nesting season, in "La Escobilla" Sanctuary. Blood samples were collected and processed to obtain plasma. The quantification of POPs in blood was carried out with an extraction technique with a focused ultrasound probe. Twenty-seven POP analytes were determined. The concentrations of hexachlorocyclohexane, endosulfan isomers, dichlorodiphenyltrichloroethane, total polychlorinated biphenyls, and the total sum of POPs found in plasma are higher than those reported in other studies, which reported effects such as hematological and biochemical changes in blood, changes in immune system cells and enzymatic activity related to oxidative stress. These results are important to demonstrate the chronic exposure to POPs in olive ridley turtles in marine ecosystems and to highlight the importance of assessing the associated health risks, considering that these contaminants could be transferred to the offspring and affect future generations of this reptile. It is important to carry out studies that develop conservation strategies for the olive ridley turtle. Also, it is necessary to control the emissions of pollutants into the atmosphere, as well as reduce urban, agricultural, and industrial waste in the environment and marine ecosystems.

Polychlorinated naphthalenes (PCNs) in food products in Latvia: Congener-specific analysis, occurrence, and dietary exposure of the general population

A study was performed to evaluate the dietary exposure of the Latvian population to polychlorinated naphthalenes (PCNs). Based on the toxicological characteristics, provisional levels of occurrence, congener patterns, and the availability of analytical standards, twenty-six congeners were included in the analysis. Considering the planar structure of PCNs, an analytical protocol on the basis of destructive clean-up and isolation of analytes on carbon was applied, while GC-HRMS and isotope dilution were used for the detection and quantification of analytes. Commonly consumed foods were analyzed for the content of PCNs, followed by per capita intake calculations. By applying the available in vitro relative potency (REP) factors, putative toxic equivalents (TEQ) were determined, in order to assess the "dioxin-like" effect arising from the presence of PCNs in food. The daily intake (EDI) for total PCNs (∑_PCN) and PCN-TEQ for the general population were calculated to be 116 pg kg^-1 body weight (b.w.) and 0.036 pg TEQ kg^-1 b.w., respectively. Fish and fish products were found to provide the main contribution to the dietary "dioxin-like" burden of PCNs, constituting ∼60% of the total PCN-TEQ intake. For some fish samples, PCN-TEQ could additionally contribute up to ∼3% to the regulated PCDD/F-PCB-TEQ, while for other matrices this contribution could be lower by an order of magnitude. The obtained data indicated that the estimated dietary exposure to PCNs is likely to be of low concern, although PCN-TEQ could be recognized as a contributor to the overall "dioxin-like" TEQ loading that results from the exposure to halogenated aromatics.

Persistent organic pollutants in Kemp's Ridley sea turtle Lepidochelys kempii in Playa Rancho Nuevo Sanctuary, Tamaulipas, Mexico

Persistent organic pollutants (POP) are toxic substances for wildlife and people. The Kemp's Ridley sea turtle Lepidochelys kempii is an endangered species with limited distribution in the Gulf of Mexico (GM), a marine ecosystem that has been perturbed by a variety of anthropogenic activities. In this work, the concentrations of ten organochlorine pesticides (OP), eight polychlorinated biphenyls (PCB), and atrazine were determined in the plasma of Kemp's Ridley sea turtles that nest in Playa Rancho Nuevo Sanctuary, Tamaulipas, Mexico. Seventy-nine blood samples were collected from female turtles during the 2015-2016 nesting season. Samples were extracted with a focalized ultrasonic sound technique and analyzed through Gas Chromatography coupled to a Mass Spectrometer. POP with the highest percentage of detection were atrazine > PCB 52 > PCB 153 > DDE > alpha endosulfan > DDD > alpha HCH > DDT. There is no linear correlation between the detected POP levels in the Kemp's Ridley sea turtle plasma and its curve carapace length (CCL). When comparing 2015 and 2016 POP concentrations, there were statistically significant differences in atrazine (p < 0.05, R² = 0.069), PCB 52 (p < 0.05, R² = 0.0051) and ∑POP (p < 0.05, R² = 0.0001) and, no statistically significant differences in alpha endosulfan (p < 0.05, R² = 0.0294), DDE (p < 0.05, R² = 0.0315) and PCB 153 (p < 0.05, R² = 0.0036). The reported POP values of this work are one of the few registered for Kemp's Ridley sea turtle in the GM and the first for atrazine levels. These levels were higher than those reported for other sea turtle species from America, Africa, and Europe, which demonstrates a deteriorated health status of the GM marine ecosystem.

Simultaneous Quantification of Aflatoxin B1, T-2 Toxin, Ochratoxin A and Deoxynivalenol in Dried Seafood Products by LC-MS/MS

Mycotoxins are secondary metabolites produced by fungi. These contaminate dried seafoods during processing and storage and represent a potential health hazard for consumers. A sensitive, selective and accurate liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was established for simultaneous quantification of four common mycotoxins (aflatoxin B₁ (AFB₁), T-2 toxin (T-2), ochratoxin A (OTA) and deoxynivalenol (DON)) in dried shrimp, dried fish and dried mussel products. Mycotoxins were extracted from dried seafood samples by acetonitrile/water (85/15, v/v), subjected to ultrasound for 60 min at 20 °C and cleaned up by defatting with n-hexane. The sample matrix affected the linearity of detection (R² ≥ 0.9974). The limit of detection (LOD) and limit of quantification (LOQ) in dried seafood products varied from 0.1 to 2.0 µg·kg⁻¹ and 0.3 to 5.0 µg·kg⁻¹, respectively. The method was validated by spiking samples with specific mycotoxin levels, and the recoveries, intra-relative standard deviation (RSDs) and inter-RSDs ranged between 72.2–98.4%, 2.8–10.6%, and 5.5–15.4%, respectively. This method was used to analyze 40 dried seafood products purchased from the Zhanjiang seafood market. Results of this product sampling showed that while no DON was detected, AFB₁, T-2 and OTA were detected in 30.8%, 17.5% and 33.3% of the samples, respectively. AFB₁, T-2 and OTA concentrations varied at 0.58–0.89, 0.55–1.34 and 0.36–1.51 µg·kg⁻¹, respectively. Relatively high frequency of contamination and the presence of AFB₁, OTA and T-2 residues indicate the need to monitor mycotoxins in dried seafood products.

Evaluation of emerging biomarkers of renal damage and exposure to aflatoxin-B1 in Mexican indigenous women: a pilot study

Aflatoxins (AFs) are mycotoxins produced by Aspergillus parasiticus and Aspergillus flavus which frequently contaminate maize. These compounds are considered toxic, especially AFB₁ which has been classified as a human carcinogen, due to its relationship with the generation of hepatocellular carcinoma. Studies in vivo, in animal models, prove that chronic consumption of AFB₁ has an association with renal adverse effects, but evidence in humans is scarce. Therefore, the main objective of this research was to conduct a pilot study to evaluate the correlation between exposure to AFB₁ and early-stage renal damage in indigenous women of San Luis Potosí, Mexico. Exposure to AFB₁ was measured through the biomarker AFB₁-lysine and renal damage through kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and cystatin-C (Cys-C). AFB₁-Lys was measured by HPLC-FLD. The method was validated with a correlation coefficient of 0.99 and limit of detection and quantification of 3.5 and 4.7 pg mL^-1, respectively. Levels of NGAL, KIM-1, and Cys-C were determined (median (P25-P75), 5.96 (3.16-15.91), 0.137 (0.137-0.281), and 18.49 (5.76-29.57) ng mL^-1, respectively). Additionally, glomerular filtration rate (GFR) (83.3 (59.8-107.4) mL/min/1.73 m²) and serum creatinine (SCr) (0.88 (0.72-1.22) mg dL^-1) were obtained. The median concentrations for AFB₁-Lys were 2.08 (1.89-5.8) pg mg^-1 of albumin. Statistically significant correlations between AFB₁-Lys/KIM-1 (Rho = 0.498, p = 0.007) and AFB₁/Cys-C (Rho = 0.431, p = 0.014) were found. Our results indicate that women are exposed to AFB₁, due to the fact that the AFB₁-Lys biomarker was found in a high percentage of the study population (83%). In addition, the results of exposure to AFB₁ show a strong significant correlation between KIM-1 and Cys-C that may indicate the toxic renal effect. These results are alarming because of the high toxicity of this compound and require adequate intervention to reduce AFB₁ exposure in these populations.

DNA damage in earthworms by exposure of Persistent Organic Pollutants in low basin of Coatzacoalcos River, Mexico

Persistent Organic Pollutants (POPs) are stable organic chemicals that represent a potential risk for ecosystems due to their high toxicity, persistence and biomagnification through food chains. Bioindicators in ecosystems have emerged to assess the effect of environmental pollutants. Earthworms are some of the most common bioindicator organisms in terrestrial ecosystems. The main objective of this study was to evaluate the geontoxicity of POP exposure in wild earthworms captured at different levels of urbanization throughout the lower basin of the Coatzacoalcos River (industrial, urban and rural areas). POP soil and earthworm tissue concentrations were measured via Gas-Mass Chromatography, and earthworm DNA damage was evaluated through the comet assay. The greatest concentrations of ΣPOPs, DDT and HCH were found in soil from industrial sites, followed by urban and rural areas (504.68, 383.10, 298.16; 22.6, 4.6, 2.6 and 433.7, 364, 255.6 mg/kg, respectively). Unlike other pollutants, mean ΣPCBs values were highest for industrial soil samples, followed by those from rural and urban areas (41.10, 33.97 and 12.44 mg/kg respectively). For all earthworm tissue POP analyses, the highest concentrations were found in individuals from industrial sites, followed by the urban and rural areas. Furthermore, the highest levels of DNA damage were registered in the industrial area, followed by the urban and rural areas. These assays suggest a strong links among regional soil contamination, POPs bioavailability and the potential risk of detrimental health effects for organisms that inhabit surface soil (soil life). Earthworms contribute vital ecosystem services that could be affected by these results. This work provides evidence of the potential ecological risk that exists in the Lower Basin of the Coatzacoalcos River.

Application of Focused Ultrasound-Assisted Extraction for the Quantification of Persistent Organic Pollutions in Liver Tissue of Giant Toad (Rhinella marina)

A simple and rapid focused ultrasound extraction method was developed for the determination of Persistent Organic Pollutants (POPs) in liver tissue obtained of giant toad (Rhinella marina) using a gas chromatography coupled to a mass detector with electron impact ionization. The performed method for POPs, was validated in fortified matrix, showing linearity from the LOQ up to 100 ng/mL; LODs and LOQs for each compound were between 1.7 and 4.8 and 3.5-7.5 ng/mL, respectively. Recovery rates were among 79%-116% for POPs determined. Finally, the method was applied in liver samples of giant toads found in a malarial area in Mexico. The sensitivity of the proposed method was good enough to ensure reliable determination of target analytes at concentration levels commonly found in this kind of samples.