Background: Cadmium (Cd) is toxic heavy metal that accumulates in organisms after passing through their respiratory and digestive tracts. Although several studies have reported the toxic effects of Cd exposure on human health, its role in embryonic development during preimplantation stage remains unclear. We investigated the effects of Cd on porcine embryonic development and elucidated the mechanism. Methods: We cultured parthenogenetic embryos in media treated with 0, 20, 40, or 60 μM Cd for 6 days and evaluated the rates of cleavage and blastocyst formation. To investigate the mechanism of Cd toxicity, we examined intracellular reactive oxygen species (ROS) and glutathione (GSH) levels. Moreover, we examined mitochondrial content, membrane potential, and ROS. Results: Cleavage and blastocyst formation rates began to decrease significantly in the 40 μM Cd group compared with the control. During post-blastulation, development was significantly delayed in the Cd group. Cd exposure significantly decreased cell number and increased apoptosis rate compared with the control. Embryos exposed to Cd had significantly higher ROS and lower GSH levels, as well as lower expression of antioxidant enzymes, compared with the control. Moreover, embryos exposed to Cd exhibited a significant decrease in mitochondrial content, mitochondrial membrane potential, and expression of mitochondrial genes and an increase in mitochondrial ROS compared to the control. Conclusions: We demonstrated that Cd exposure impairs porcine embryonic development by inducing oxidative stress and mitochondrial dysfunction. Our findings provide insights into the toxicity of Cd exposure on mammalian embryonic development and highlight the importance of preventing Cd pollution.

The ecosystem provides a diverse array of environmental conditions for organisms, and only those that are capable of successfully adapting to these conditions within their habitats can endure, thrive, and proliferate. Further, the environmental conditions within these habitats can significantly affect the bioavailability of chemicals that are introduced therein, thus resulting in varied adverse impacts on the organisms. The present study aims to evaluate the sensitivity of Yuukianura szeptyckii - a species adapted to riparian - to heavy metals following ISO guideline 11276, with the objective of assessing its potential as an indicator species for ecotoxicological evaluations in riparian habitats. The findings revealed that cadmium and copper both had significant toxic effects depending on their concentrations. For cadmium, the LC50 was 280 mg kg-1, EC50 was 66 mg kg-1, and NOEC and LOEC were 25 and 50 mg kg-1, respectively. For copper, the LC50 was 911 mg kg-1, EC50 was 151 mg kg-1, and LOEC was 50 mg kg-1. Comparative analysis with previous results for the international standard species Folsomia candida and the domestic standard species Allonychiurus kimi indicated that Y. szeptyckii exhibited even greater sensitivity to toxicity values. The adverse effects on survival and reproduction were closely associated with the influx concentration of heavy metals in their bodies. Altogether, the results suggest that Y. szeptyckii is a sensitive species for ecotoxicological assessments in riparian habitats, thus making it suitable as an indicator species, particularly in riparian ecosystems that are characterized by relatively high humidity conditions.

Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg-1 Cd, 96% at 1.87 mg kg-1 Cd, and 93% at 6.09 mg kg-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg-1, 13.06 mg kg-1, and 79.11 mg kg-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.

For practical applications of graphene sheets in a variety of fields, mass production of high-quality graphene sheets is necessary. Herein, we reported a cost-effective, green, and simple approach to synthesizing mass production exfoliated graphene (EG) flakes employing electrochemical exfoliation of pencil graphite in neutral aqueous electrolytes. Pencil graphite cores of different grades were applied as anode and cathode electrodes and exposed to the electrolyte solution at a different voltage. Several parameters were examined and optimized, including pencil grade (2,4,6,8 B), applied voltage (10, 15, 20, 30 V), different inorganic electrolytes ((NH4)2SO4, Na2SO4, NaNO3, NaCl, and CH3COONa), and the concentration of electrolytes. The optimal condition was chosen by considering the mass of produced graphene and the conductivity of the graphene solution. The optimal conditions were as follow: pencil grade: 6B; applied voltage: 10 V; electrolyte type: Na2SO4; electrolyte concentration: 0.1 M. Under these conditions, the production yield was > 95% within 3 h and 9 min. The EG was characterized by utilizing FT-IR, XRD, Raman spectroscopy, FE-SEM, Cyclic Voltammetry, and Electrochemical Impedance Spectroscopy (EIS). Characterization indicates that the synthesized EG had an XRD peak at 2θ = 26.6° and an ID/ IG ratio of 0.36. Furthermore, the EG showed good conductivity when tested by cyclic voltammetry and EIS whereas the R2 values were 985.8 and 76.3 Ω for bare GCE and EG/GCE, respectively. In addition, EG effectively removed cadmium (Cd(II)) with an adsorption level of 8.72 mg/g. The results from this study suggest that EG can be scaled up and commercialized in an environmentally friendly and low-cost manner, especially in low-income countries, and using it to rectify metal ions.

This study was undertaken to evaluate the toxic effect of cadmium sulfate (Cds) on planarians (Dugesia japonica), and the suitability of planarians as an alternative animal model for toxicity studies. Planarians were exposed to varying concentrations of experimental solutions containing 0.1–25 mg/L Cds, and incubated for 1, 3, and 5 hrs. Motility, seizure-like behaviors (c-like, head-bop, snake-like, and screw-like) and regeneration ability of the amputated fragment were subsequently evaluated. Results showed decreased motility with increasing concentrations of Cds (p<0.05), with the lowest motility being observed at the highest concentration of 25 mg/L Cds. Results also indicate that seizure-like behavior patterns were significantly affected by increments in the Cds concentrations, especially the c-like and head-bop behaviors were notably increased. Compared to the control, the regeneration ability of the planarians was decreased in the experimental solutions containing Cds. Planarians exposed to Cds showed either delayed eye formation or no eye regeneration during incubation. Moreover, increased concentrations of Cds resulted in failure to regenerate and death of the planarians. In conclusion, this study confirm that the heavy metal Cds exerts a toxic effect on planarians. Furthermore, the performances of the planarians in the experimental period exhibit their suitability as an alternative animal model for toxicity studies.

국내외적으로 유해물질의 통합 노출에 대한 관심은 높아지고 있다. 이러한 흐름에 따라 다양한 경로를 통해 노출될 수 있는 중금속에 대한 통합 노출 연구가 필요하다. 카드뮴과 납은 각각 신장 독성과 인지 장애 등 다양한 독성을 나타낼 수 있으며 또한 발암 물질로 알려져있다. 따라서 본 연구에서는 카드뮴과 납의 노출량 추정 및 통합 위해성 평가를 진행하였다. 2016, 2017년의 7기 국민건강 영양조사에 참여한 10,733명의 식품, 물, 흡연과 간접흡연, 호흡, 화장품, 여성용 위생용품을 통한 중금속 노출 추정량을 계산하였다. 결과적으로 카드뮴과 납 모두 식품을 통한 노출이 제일 높게 나타났다. 이외에도 흡연은 카드뮴의 주요한 노출원이었으며, 납은 화장품을 통해 높은 농도로 노출되었다. 통합 위해평가에서도 식품이 가장 큰 영향을 미쳤다. 지역적 특성의 차이는 노출 추정량의 차이를 보이지 못하였으나, 연령 별, 성별 간 노출 추정량은 큰 차이를 보였다. 특히, 월경 중인 성인 여성의 경우 카드뮴, 월경 중이지 않은 여성은 납의 노출 추정량이 더 높으며 신체 대사를 고려하였을 때, 그 위험성이 더 클 수 있음을 암시하였다. 결론적으로 노출량 추정 및 통합 위해평가 모두 식품이 주요 노출원이었다. 다만, 잠재적 위험을 방지하기 위해 다른 경로에 대한 노출량 추정 및 위해평가가 요구된다.

Cadmium (Cd) toxicity is a serious limitation for agricultural production. In this study, we explored tolerance mechanism associated with Cd toxicity tolerance in alfalfa plants. We used three distinct alfalfa cultivars M. sativa cv. Vernal, M. sativa cv. Zhung Mu, and M. sativa cv. Xing Jiang Daye in this study. Cd showed declined chlorophyll score in Xing Jiang Daye compared with Zhung Mu and Vernal. No significant change observed among the cultivars for root and shoot length. Atomic absorption spectroscopy analysis demonstrated a significant accumulation of Cd, Fe, S and PC in distinct alfalfa cultivars. However, Zhung Mu and Xing Jiang Daye declined Cd accumulation in root, where Fe, S and PC incremented only in Zhung Mu. It suggests that excess Cd in Zhung Mu possibly inhibited in root by the increased accumulation of Fe, S and PC. This was further confirmed by the response of Fe (MsIRT1) and S transporters (MsSULTR1;2 and MsSULTR1;3), and MsPCS1 genes associated with Fe, S and PC availability and translocation in roots and shoots. It suggests that specially the transcript signal inducing the responses to adjust Cd especially in Zhung Mu. This finding provides the essential background for further molecular breeding program for forage crops.

본 연구에서는 국내 유통 중인 농산물 9품목(n = 578)에 대한 납과 카드뮴 함량을 조사하고 이들의 섭취로 인한 위해성을 평가하고자 하였다. 납과 카드뮴의 함량은 마이크로웨이브 분해 후 ICP-MS로 분석하였다. 조사대상 농산물의 납 평균 함량은 각각 보리 0.014 mg/kg, 완두콩 0.010 mg/kg, 강낭콩 0.008 mg/kg, 녹두 0.006 mg/kg, 파인애플 0.008 mg/kg, 살구 0.016 mg/kg, 매실 0.015 mg/kg, 자두 0.021 mg/kg, 대추 0.019 mg/kg이었고, 카드뮴 평균함량은 보리 0.017 mg/kg, 완두콩 0.004 mg/kg, 강낭콩 0.007 mg/kg, 녹두 0.005 mg/kg, 파인애플 0.001 mg/kg, 살구 0.002 mg/kg, 매실 0.002 mg/kg, 자두 0.002 mg/kg, 대추 0.003 mg/kg이었다. 모든 시료의 납, 카드뮴 함량은 EU, CODEX 및 국내 기준보다 낮은 수준이었다. 조사 대상 농산물에 대한 납, 카드뮴의 인체노출량을 산출한 결과, 납은 잠정주간섭취허용량(PTWI, 25 μg/kg b.w./week)의 0.067%, 카드뮴은 월간잠정섭취허용량(PTMI, 25 μg/kg b.w./month)의 0.28%이었다. 이상의 결과는 조사 대상 농산물의 납, 카드뮴 오염도와 이들의 섭취에 의한 위해성이 모두 낮은 수준이라는 것을 보여준다.

In this research, a novel and efficient quinoline thioacetamide functionalized magnetic graphene oxide composite (GO@Fe3O4@QTA) was synthesized and utilized for dispersive magnetic solid phase preconcentration of Cd(II) and Ni(II) ions in urine and various food samples. A number of diverse methods were employed for characterization of the new nanosorbent. The design of experiments approach and response surface methodology were applied to monitor and find the parameters that affect the extraction performance. After sorption and elution steps, the concentrations of target analytes were measured by employing FAAS. The highest extraction performance was achieved under the following experimental conditions: pH, 5.8; sorption time, 6.0 min; GO@Fe3O4@QTA amount, 17 mg; 2.4 mL 1.1 mol L-l HNO3 solution as the eluent and elution time, 13.0 min. The detection limit is 0.02 and 0.2 ng mL-1 for Cd(II), and Ni(II) ions, respectively. The accuracy of the new method was investigated by analyzing two certified reference materials (sea food mix, Seronorm LOT NO 2525 urine powder). The interfering study revealed that there are no interferences from commonly occurring ions on the extractability of target ions. Finally, the new method was satisfactorily employed for rapid extraction and determination of target ions in urine and various food samples.

카드뮴과 같은 중금속은 독성이 높아 수서 생물과 인간에게 해로운 영향을 미친다고 알려져 있다. 본 연구에서는 해양 섬모충 Euplotes crassus에서 카드뮴이 해독 기전에 관여하는 ABC transporters (ABCs)와 glutathione S-transferase (GST)의 유전자 발현에 미치는 영향을 조사하였 다. 총 7개의 ABCs 유전자와 1개의 GST 유전자 일부를 클로닝하여 유전자 분석을 실시하였고, 카드뮴(0.1~1 mg/l) 노출에 따른 이들 유전자의 발현 양상을 quantitative real time RT-PCR (qRT-PCR)을 이용하여 분석하였다. 염기서열 분석과 계통 분석 결과 이들 ABCs 유전자가 ABC transporter의 특징을 가지며, ABC-B/C family에 속하는 것을 확인하였고, GST 유전자는 theta isoform과 유사한 것으로 나타났다. 카드뮴에 8시간 노출시킨 결과 ABC transporter 유전자의 경우 ABCB21 유전자를 제외하고는 대부분 농도 의존적으로 유전자 발현이 유의하게 증가하였 다. GST 유전자는 0.5 mg/l에서 가장 높은 유전자 발현 양상을 보였으며, 1 mg/l에서는 발현량 이 대조군 수준으로 감소되었다. 본 연구 결과는 E. crassus의 ABC transporter와 GST 유전자가 카드뮴에 의해 유도되는 독성에 대한 방어 기전에 참여하는 것을 의미한다.