Ultrastructural changes of the digestive tract of Pomacea canaliculata exposed to copper at lethal concentration

The present study was undertaken to elucidate the basis of cellular reactions and to verify the suitability of Pomacea canaliculata digestive tract ultrastructure as a biomarker for assessing the Cu pollution in freshwater environments. Two-month-old P. canaliculata were exposed to 96-h lethal concentration of Cu (0.15 mg L-1) for 96 h. Electron microscope investigations showed different alterations of organelles in the epithelial cells lining the esophagus and intestine. The most striking changes were damages to the mitochondria, RER, and nucleus typified by loss of cristae and degeneration of mitochondria; degranulation and fragmentation of RER. In nucleus, karyolysis and rupture of nuclear envelope were observed. These changes were attributed to membrane destabilization and increased membrane permeability to ions under the influence of toxicants or heavy metals. These findings indicate the possibility of using the P. canaliculata as biomonitor for Cu contamination in the freshwater environment

Multiclass analysis of antimicrobial drugs in shrimp muscle by ultra high performance liquid chromatography-tandem mass spectrometry

A reliable, selective and rapid multiclass method has been developed for the simultaneous determination of 55 antibacterial drug residues in shrimp muscle samples by ultra high performance liquid chromatography-tandem mass spectrometry. The investigated compounds comprise of eight different classes, namely fluoroquinolones, sulfonamides and synergistic agents, tetracyclines, macrolides, lincosamides, penicillins, nitroimidazole and amphenicols. A simple liquid extraction procedure was developed consisting of extraction with a mixture of acetonitrile and ethylenediaminetetraacetic acid (EDTA), followed by a defatting step with n-hexane. Chromatographic conditions were optimized, obtaining a running time <10 min. Mean recoveries ranged from 74.3% to 113.3%. For precision test, relative standard deviations (RSD, %) were lower than 15.0% and 24.0% for repeatability and reproducibility, respectively. Limits of detection and quantification ranged from 1.0 to 5.0 ng/g and 3.0–10.0 ng/g, respectively. Finally, the method was applied to real samples and the results demonstrated that enrofloxacin, ciprofloxacin, pefloxacin and doxycycline were quantifiable in shrimp samples. Keywords: Antimicrobial drugs, Multiclass analysis, Shrimp, UHPLC-MS/M

Heavy metal concentrations in duck eggs and potential human health risk via consumption

Heavy metals commonly found in environmental matrices are from natural or anthropogenic activities. Their contamination effects especially on human health from non-degradable properties are of major concern. The aims of this study, thus, were to determine Cd, Cu, Fe, Mn, Ni, Pb and Zn residues in duck eggshells, yolk and albumin, and to investigate the correlations of these metal residues with the surrounding environmental media (soil, water, and feed). Target hazard quotient (THQ) of individual heavy metal was used to evaluate potential human health risk via egg consumption. Thirty duck egg samples were randomly collected from each free range laying duck farm (total of 8 farms). The samples collected were analyzed for heavy metal concentrations using the flame atomic absorption spectrometry (FAAS). Results showed that average concentrations of Fe (71.96±1.33 μg/g dw) in yolk and Pb (6.76±0.21 μg/g dw) in albumin were significantly highest when compared to other investigated metals, whereas Cu concentration was mostly found in egg shells. In addition, the predominantly found metal in soil samples was Fe, whereas in water and feed samples were Ni and Pb, respectively. Principle component analysis (PCA) revealed that the concentrations of heavy metals found in eggshells and egg contents are highly correlated with their concentrations in the surrounding water and soil matrices as well as feed. The THQs for Pb, which were greater than 1, indicated that there could be potential for human health risks upon consumption of contaminated duck eggs

Using Nassarius stolatus as a potential heavy metal biomonitor

Nassarius stolatus was evaluated as the potential heavy metal (Cd, Fe, Mn, Ni and Pb) accumulator in Don Hoi Lot sandbar, Samut Songkhram province, Thailand. This selected species belongs to the Gastropoda, which is widely distributed in the coastal areas from the upper Gulf through the southern part of Thailand. From our findings, the heavy metal accumulations in N. stolatus tissues were Fe ＞ Pb ＞ Mn ＞ Ni ＞ Cd. The retrieved bioaccumulation factor (BAF) indicated that N. Stolatus has high potential to be a biomonitor for the contaminations of Fe and Mn in water and Cd, Ni and Pb in sediment

Fate and tissue depletion of nivalenol in ducks

Nivalenol (NIV), a mycotoxin belonging to the trichothecenes type B group, has recently been identified as causing one of the more potent toxicities among mycotoxins of this group. The purpose of this study was to clarify the toxicokinetics, and residues of NIV in ducks. Then, NIV was administered intravenously (iv) or orally (po) to ducks at a dosage of 0.8 mg/kg body weight. The concentrations of NIV in plasma and various tissues were quantified using liquid chromatography tandem-mass spectrometry. The plasma concentrations of NIV were measurable up to 12 h after iv and po administrations, respectively. A non-compartmental model was used to describe the toxicokinetics of NIV in ducks. The values of elimination half-life and volume of distribution were 2.24 ± 0.34 h and 1081.87 ± 306.56 ml/kg, respectively, after iv administration. The absolute oral bioavailability was 8.91 ± 1.69%. NIV was measurable in the vital organs after po administration. These results suggest that NIV is not favorably absorbed from the gastrointestinal tract, but it has the ability to penetrate into the various tissues of ducks

Human Health Risk Assessment of Heavy Metal Concentration in Seafood Collected from Pattani Bay, Thailand

A significant impact of marine pollution is the contamination of seafood which has raised concerns due to its potential human health risks. This current study investigated seasonal bioaccumulation of 9 heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in 14 commercially important seafood species, including 4 fish, 5 molluscs, and 5 crustacean species. Samples were collected from Pattani Bay, Pattani province, Thailand, during the dry (July 2020) and wet (February 2021) seasons. The edible samples were analyzed for heavy metal concentrations using a flame atomic absorption spectrophotometer. The bioaccumulation trend of heavy metals decreased in the sequence of molluscs > crustaceans > fish. The possible human health risks associated with heavy metal-contaminated seafood consumption were assessed. The parameters investigated for non-carcinogenic and carcinogenic were target hazard quotient (THQ), total hazard index (HI), and target cancer risk (TR). The average ranges of THQs (7.79 × 10−8–8.97 × 10−3), HIs (4.30 × 10−5–1.55 × 10−2), and TRs (2.70 × 10−9–1.34 × 10−5) were observed in the studied seafood species. The results revealed no non-carcinogenic and carcinogenic health risks from consuming these 14 kinds of seafood

Environmental factors induced crop raiding by wild Asian elephant (Elephas maximus) in the Eastern Economic Corridor, Thailand

Abstract Crop raiding are an increasing concern in wildlife conservation. This study identified the environmental factors that cause wild Asian elephants (Elephas maximus) to enter sub-urban and rural areas and share resources with humans in the Eastern Economic Corridor (EEC) in the eastern part of Thailand. The snowball method was used to interview villagers that had crop raiding experienced in seven provinces of the EEC and adjacent provinces in the eastern part of Thailand in 2020, and data from 183 households indicated that crop raiding had increased continuously from 2000 to 2020, especially in Chonburi, Chachoengsao, and Prachinburi provinces, which have seen increases in damaged agricultural areas. MaxEnt analysis showed an increase in incidents of crop raiding, while the elephants distribution area decreased from 9534 km2 in 2000 to 5199 km2 in 2010 and 4850 km2 in 2020. The study area has had land use changes in the low elevations from croplands of cassava and sugar cane to eucalyptus, para rubber, and fruits. These mixed crop plantations provide a pseudo-habitat for wild Asian elephants. The results from this study provide evidence that changes in land use and reduction of suitable habitat are factors that influenced the movement of wild Asian elephants to the rural agricultural areas and increased the incidents of crop raiding