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Atmospheric mercury pollution caused by fluorescent lamp manufacturing and the associated human health risk in a large industrial and commercial city
2021
Luo, Qing | Ren, Yuxuan | Sun, Zehang | Li, Yu | Li, Bing | Yang, Sen | Zhang, Wanpeng | Hu, Yuanan | Cheng, Hefa
Although already eliminated in most industrial processes, mercury, as an essential ingredient in all energy-efficient lighting technologies, is still used in fluorescent lamp manufacturing. This study was conducted to investigate the atmospheric pollution caused by fluorescent lamp production and assess the associated public health risk in a large industrial and commercial city of south China, Zhongshan, which is a major production hub of lighting products. Concentrations of total gaseous mercury (TGM) in the atmosphere were measured over a total of 342 sites in the industrial, commercial, and residential areas. The average levels of TGM in the industrial, commercial, and residential areas prior to the landing of a typhoon were 12 ± 11, 3.6 ± 2.1, and 2.7 ± 1.3 ng⋅m⁻³, respectively. TGM concentrations in the industrial areas exhibited significant diurnal variation, with levels in the working hours being much higher than those in the non-working hours, which indicates that the high atmospheric mercury concentrations were contributed by local emissions, instead of regional transport. Most fluorescent lamp manufacturing activities in the city were shut down during a typhoon event, which resulted in a significant reduction in the average TGM level (down to 1.6 ± 1.8 ng⋅m⁻³) and rendered the difference in the average TGM levels in the industrial areas no longer significant between the working and non-working hours. Elevated TGM levels (up to 49 ng⋅m⁻³) were found near clusters of small-scale fluorescent lamp workshops in both industrial and commercial areas, which is indicative of significant emissions of mercury vapor resulting from obsolete equipment and production technologies. No significant non-carcinogenic risk was found for the general residents in the sampling area over the study period, while the risk for the workers in the fluorescent lamp manufacturing facilities and workshops could be higher. These findings indicate that fluorescent lamp manufacturing in the developing countries is a major source of atmospheric mercury.
Show more [+] Less [-]Arsenic speciation in rice bran: Agronomic practices, postharvest fermentation, and human health risk assessment across the lifespan
2021
Weber, Annika M. | Baxter, Bridget A. | McClung, Anna | Lamb, Molly M. | Becker-Dreps, Sylvia | Vilchez, Samuel | Koita, Ousmane | Wieringa, Frank | Ryan, Elizabeth P.
Arsenic (As) exposure is a global public health concern affecting millions worldwide and stems from drinking water and foods containing As. Here, we assessed how agronomic practices and postharvest fermentation techniques influence As concentrations in rice bran, and calculated health risks from consumption. A global suite of 53 rice brans were tested for total As and speciation. Targeted quantification of inorganic As (iAs) concentrations in rice bran were used to calculate Target Hazard Quotient (THQ) and Lifetime Cancer Risk (LCR) across the lifespan. Mean iAs was highest in Thailand rice bran samples (0.619 mg kg⁻¹) and lowest in Guatemala (0.017 mg kg⁻¹) rice bran samples. When comparing monosodium-methanearsonate (MSMA) treated and the Native-soil counterpart under the irrigation technique Alternate Wetting and Drying (AWD) management, the MSMA treatment had significantly higher total As (p = 0.022), and iAs (p = 0.016). No significant differences in As concentrations were found between conventional and organic production, nor between fermented and non-fermented rice bran. Health risk assessment calculations for the highest iAs-rice bran dosage scenario for adults, children and infants exceeded THQ and LCR thresholds, and LCR was above threshold for median iAs-rice bran. This environmental exposure investigation into rice bran provides novel information with food safety guidance for an emerging global ingredient.
Show more [+] Less [-]Bioassay-based ecotoxicological investigation on marine and freshwater impact of cigarette butt littering
2021
Oliva, M. | De Marchi, L. | Cuccaro, A. | Pretti, C.
Despite representing an extremely relevant portion (20–40%) of worldwide coastal litter, cigarette butts are still an underestimate environmental issue of limited scientific interest. Public authorities of different countries promote active removal of cigarette butts, but the issue remains problematic in terms of aesthetic, environmental and health-related impacts. There are few studies on the environmental side-effects of smoked cigarette butt litter despite being a worldwide issue. In this work, two ecotoxicological bioassay batteries were adopted to evaluate the environmental consequences of cigarette butt water-soluble ingredient release in both marine water and freshwater. Marine assays were generally more affected compared to freshwater. Interesting outcomes were observed with crustacean tests, showing a lower effect of smoked cigarette butt leachate when tested at maximum concentration. This finding were supported by heartbeat measures of Daphnia magna, which were accelerated at 100% of smoked cigarette butt leachate.
Show more [+] Less [-]Fixation stability of glass matrix co-existent with crystal phases for heavy metals formed by high-temperature vitrification
2021
Vitrification is an effective solidification method for heavy metal-containing wastes. However, most investigations focused on the formation of glass matrix. Seldom report discussed the influence of co-existing crystals on heavy metal stabilizations. In this work, Ca-Al-Si phase was formed in the glass matrix by adjusting the composition of feeding ingredient and melting temperature. As a result, when molar ratio of CaO/(SiO₂+Al₂O₃) was lower than 0.97 and reaction temperature was bigger than 1300 °C, small-size Ca-Al-Si phase (Ca₂Al₂SiO₇ and CaAl₂Si₂O₈) was homogeneously distributed in vitreous matrix. At the same time, Cr, Zn, and Pb leaching concentrations were the lowest, far lower than the leaching standard values. According to theoretical calculations, Zn and Pb replaced Ca atom; Cr replaced Al atom in Ca-Al-Si phase under thermal conditions. These replacements resulted in the fixation and stabilization of heavy metals. When the CaO/(SiO₂+Al₂O₃) molar ratio was bigger than 1.00, neither glass nor Ca-Al-Si was formed. Similarly, when the melting temperature was decreased, Ca-Al-Si phase formed a bigger size. Both these went against the stabilization, resulting in high leaching concentrations of heavy metals. The main of this work will help the development of high-temperature melting for the treatment of hazardous wastes.
Show more [+] Less [-]Potential application and beneficial effects of a marine microalgal biomass produced in a high-rate algal pond (HRAP) in diets of European sea bass, Dicentrarchus labrax
2021
Pascon, Giulia | Messina, Maria | Petit, Lisa | Valente, Luisa Maria Pinheiro | Oliveira, Beatriz | Przybyla, Cyrille | Dutto, Gilbert | Tulli, Francesca
Microalgae have been used as live food in aquatic species. In recent years, the interest in microalgae has considerably increased, thanks to the evolution of production techniques that have identified them as an ecologically attractive aquafeed ingredient. The present study provides the first data about the effects of dietary inclusion of a microalgae consortium grown in a high-rate algal pond system on zootechnical performance, morphometric indices, and dietary nutrient digestibility as well as morphology and functionality of the digestive system of European sea bass, Dicentrarchus labrax. A dietary treatment including a commercial mono-cultured microalgae (Nannochloropsis sp.) biomass was used for comparison. Six hundred and thirty-six European sea bass juveniles (18 ± 0.28 g) were randomly allotted into 12 experimental groups and fed 4 different diets for 10 weeks: a control diet based on fish meal, fish oil, and plant protein sources; a diet including 10% of Nannochloropsis spp. biomass (100 g/kg diet); and two diets including two levels (10% and 20%) of the microalgal consortium (100 and 200 g/kg diet). Even at the highest dietary inclusion level, the microalgal consortium (200 g/kg diet) did not affect feed palatability and fish growth performance. A significant decrease in the apparent digestibility of dry matter, protein, and energy was observed in diets including 10 and 20% of the microalgal consortium, but all fish exhibited a well-preserved intestinal histomorphology. Moreover, dietary inclusion with the microalgal consortium significantly increased the enzymatic activity of maltase, sucrase-isomaltase, and ɤ-glutamil transpeptidase in the distal intestine of the treated European sea bass. Algal consortium grown using fish farm effluents represents an attempt to enhance the utilization of natural biomasses in aquafeeds when used at 10 % as substitute of vegetable ingredients in diet for European sea bass.
Show more [+] Less [-]Time-frequency dependency of temperature and sea level: a global perspective
2021
Kirikkaleli, Dervis | Sowah, James Karmoh Jr
The importance of environmental sustainability to all human aspects has been spiking as the world keeps evolving. Economies around the world are on the move to ensure sustainable economic development and a clean atmosphere through the use of renewable energy sources. Since the end of the nineteenth century, it is recognized that a global mean sea level rise speed about 1.7 ± 0.2 mm/year, but the rate has increased to 3.2 ± 0.4 mm/year. In this study, we investigated the dynamic linkage between average temperature and sea level within the global framework covering 1881 to 2013. The paper employs wavelet analysis to investigate the short-term and long-run causal links between global average temperature anomalies and global sea level. In this respect, our findings indicate that (i) a significant vulnerability in global average temperature and sea level is observed over the selected study period; (ii) global average temperature has considerable power for predicting sea level, particularly in the long-term. The causality test revealed a bi-directional causal relationship between global average temperature and sea level and unidirectional flow from global average temperature to sea level. And the study confirms the “conservation hypothesis,” and it has long-run implications for environmental quality. Thus, minimizing global average temperature anomalies is a decisive ingredient for minimizing sea level rise. Based on these outcomes, both developed and developing countries’ policymakers should support the Paris agreement (COP21) agreement to control CO₂ emissions growth. Policymakers should encourage the usage of environmentally friendly energy sources that will enhance environmental quality and hold the increase in global average temperature below 1.5 °C.
Show more [+] Less [-]Feasibility of Sijunzi Tang (Chinese medicine) to enhance protein disulfide isomerase activities for reactivating malate dehydrogenase deactivated by polycyclic aromatic hydrocarbons
2021
Leung, Ho Man | Kwok, Francis Siu Lai | Mo, Wing Yin | Cheung, Kwai Chung | Yue, Yik Kit | Wong, Yee Keung | Au, Chi Kin | Tsui, Martin Tsz Ki | Yung, Ken Kin Lam
The objective of this research is to investigate the enzymatic activities between protein disulfide isomerase (PDI) found in animals and plants and the properties found in a commonly used Chinese medicine called Sijunzi Tang. During the investigation, PDI, which is a monomer with a molecular mass of 57.0 kDa, was used to reactivate malate dehydrogenase (MDH). However, with the interference of polycyclic aromatic hydrocarbons (PAHs), evidence indicates that such chemicals are carcinogenic, mutagenic, and toxic to humans. The enzymatic activity of PDI found in animal’s liver and plant was 1657 folds of purification; 0.284 unit/mg of enzyme activity, and 5694.4 folds of purification; 1.00 unit/mg of enzyme activity, respectively. PDI extracted in treated animal and plant tissue revealed 2.40% and 80.44% of regaining MDH enzymatic activity, respectively. Although in its initial phase of investigation, it is assumed that the properties found in Sijunzi Tang can help regain enzymatic activity in those affected by xenobiotic substances, thus, making it a potential ingredient in assisting with PDI functions.
Show more [+] Less [-]The addition of bean curd dreg improved the quality of mixed cow manure and corn stalk composting: enhancing the maturity and improving the micro-ecological environment
2021
Wang, Bing | Yan, Jianquan | Li, Guomin | Cao, Qingtong | Chen, Houhe | Zhang, Jian
Bean curd dreg (BCD) is a by-product of bean products, which can be used as a great ingredient for composting, but it combined with cow manure and corn stalk composting was rarely reported. In this study, the effect of BCD on the maturity and the micro-ecological environment was investigated under a lab-scale composting experiment and found that BCD was conducive to improve the maturity of compost during the BCD application. The excitation-emission matrix (EEM) showed that the final humus content in BCD treatments was richer than that in CK treatment. High-throughput sequencing results showed that BCD-applied better ameliorated the bacteria community structure with higher Actinomycetes abundance and lower denitrifying bacteria abundance in the late stage of composting. PICRUSt results showed that BCD-added decreased the abundance of microbial metabolic genes in the high temperature period (> 70 °C), but the metabolic abundance increased rapidly as the temperature cooled down. Compared with CK, the metabolic abundance decreased significantly on day 24, which was consistent with the conclusion of composting maturity. Redundancy analysis (RDA) results indicated that there were significant discrepancies in the microbial community structure of samples at different composting periods and the change of the dominant population in the BCD-treated compost samples were more outstanding than that in the CK treatment. Hence, BCD is a very good composting modifier that compensates for the disadvantages of composting and enhances the fertility of the compost product.
Show more [+] Less [-]Protective effect of Lycium barbarum polysaccharide on di-(2-ethylhexyl) phthalate-induced toxicity in rat liver
2021
Liu, Rui-jing | He, Yong-jian | Liu, Huan | Zheng, Dong-dong | Huang, Shao-wen | Liu, Chun-hong
Di-(2-ethylhexyl)-phthalate (DEHP) is the most commonly used plasticizer and it has been a ubiquitous environmental contaminant which affects health. The purpose of this study was to investigate the protective effect of the Lycium barbarum polysaccharide (LBP) at dosages of 100, 200, and 300 mg/kg bw on DEHP-induced (3000 mg/kg) toxicity in rat liver through a 28-day animal experiment. The results showed that LBP attenuated oxidative stress slightly by lowering the production of ROS and improving the activity of SOD and GSH-Px in liver and serum of DEHP treatment rats. At the same time, the levels of PXR, CYP450, CYP2E1, CYP3A1, UGT1, and GST were reduced after LBP treatment. Moreover, LBP decreased the mRNA expression of PXR, UGT1, and GST significantly. These findings suggested that LBP might ameliorate DEHP-induced liver injury by down-regulating the expression of PXR in liver, further down-regulating the downstream phase I and II detoxification enzymes, thus reducing the damage caused by DEHP. Therefore, LBP may have the potential to become an auxiliary therapeutic agent as a natural ingredient of health food.
Show more [+] Less [-]Ameliorative effect of fractionated low-dose gamma radiation in combination with ellagic acid on nicotine-induced hormonal changes and testicular toxicity in rats
2021
Ashoub, Aliaa H. | Abdel-Naby, Doaa H. | Safar, Marwa M. | El-Ghazaly, Mona A. | Kenawy, Sanaa A.
Nicotine is an active pharmacological ingredient in cigarette smoke, which may negatively influence the male reproductive system and fertility. This study aims to investigate the effect of fractionated low-dose radiation (fractionated-LDR) and/or ellagic acid (EA) on nicotine-induced hormonal changes and testicular toxicity in rats. Nicotine was administrated orally (1 mg/kg) for 30 days, afterward, rats were treated with LDR (2 × 0.25 Gy/1-week interval), EA (10 mg/kg, 14 consecutive days p.o.), or a combination of both fractionated-LDR and EA. Rats were sacrificed 24 h after the last dose of treatment, then testes were dissected for histopathology examination, along with some biochemical parameters in serum and testicular tissue were evaluated. Nicotine-induced oxidative stress was evidenced by an increase in testicular thiobarbituric acid reactive substances (TBARS) and a decrease in reduced glutathione (GSH) content. Additionally, the activities of testicular androgenic enzymes were decreased, and the activity of serum lactate dehydrogenase (LDH) was significantly increased. The hormonal changes were verified by a noticeable reduction in follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone serum levels. Histological evaluation revealed that the testicular seminiferous tubules structure was distorted. On the contrary, fractionated-LDR plus EA attenuated the negative changes caused by nicotine observed through biochemical and histological findings. Accordingly, the exposure to fractionated-LDR combined with EA may be a promising candidate for treating hormonal changes and testicular toxicity caused by nicotine.
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