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Identification of epigenetic mechanisms in paddy crop associated with lowering environmentally related cadmium risks to food safety Full text
2020
Feng, Sheng Jun | Liu, Xue Song | Ma, Li Ya | khan, Irfan ullah | Rono, Justice Kipkoir | Yang, Zhi Min
Cadmium (Cd) is a toxic metal that contributes to human diseases such as pediatric cancer and cardiovascular dysfunction. Epigenetic modification caused by Cd exposure is the major factor in etiology of environmentally-relevant diseases. However, the underlying epigenetic mechanism for Cd uptake and accumulation in food crops, particularly those growing in Cd-contaminated environments, is largely unknown. This study investigated uncharacterized regulatory mechanisms and biological functions of global DNA hypomethylation at CG sites that are associated with gene expression for Cd detoxification and accumulation in the food crop rice. Mutation of the CG maintenance enzyme OsMET1 confers rice tolerance to Cd exposure. Genome-wide analysis of OsMET1 loss of function mutant Osmet1 and its wild type shows numerous loci differentially methylated and upregulated genes for Cd detoxification, transport and accumulation. We functionally identified a new locus for a putative cadmium tolerance factor (here termed as OsCTF) and demonstrated that Cd-induced DNA demethylation is the drive of OsCTF expression. The 3′-UTR of OsCTF is the primary site of DNA and histone (H3K9me2) demethylation, which is associated with higher levels of OsCTF transcripts detected in the Osmet1 and Ossdg714 mutant lines. Mutation of OsCTF in rice led to hypersensitivity to Cd and the Osctf line accumulated more Cd, whereas transfer of OsCTF back to the Osctf mutant completely restored the normal phenotype. Our work unveiled an important epigenetic mechanism and will help develop breeding crops that contribute to food security and better human health.
Show more [+] Less [-]Environmental assessment of viticulture waste valorisation through composting as a biofertilisation strategy for cereal and fruit crops Full text
2020
Cortés, Antonio | Oliveira, Luis F.S. | Ferrari, Valdecir | Taffarel, Silvio R. | Feijoo, Gumersindo | Moreira, Maria Teresa
Composting is a solid waste management alternative that avoids the emission of methane associated with its disposal in landfill and reduces or eliminates the need for chemical fertilisers if compost is applied. The main objective of this study was to analyse the environmental burdens of composting as a way to achieve a more circular valorisation of wine waste. To do so, with the purpose of identifying optimal operational conditions and determining the “hotspots” of the process, the life cycle assessment (LCA) methodology was used. The consumption of diesel fuel in machinery was determined to be the main critical point in the environmental effects of the system, followed by the transport and distribution of the compost. After the application of compost instead of mineral fertilisers, corn, tomato and strawberry crops would have a better environmental performance in most impact categories. In this sense, a maximum improvement of 65% in terrestrial ecotoxicity is achieved in strawberry cultivation. In light of the results obtained, it is demonstrated that composting is a suitable way of organic waste valorisation according to Circular Economy principles.
Show more [+] Less [-]Development of polyoxymethylene passive sampler for assessing air concentrations of PCBs at a confined disposal facility (CDF) Full text
2020
Odetayo, Adesewa A. | Reible, Danny D. | Acevedo-Mackey, Damarys | Price-Glynn, Cynthia | Thai, Le
In this study, 76 μm polyoxymethylene (POM) strips were evaluated as a passive air sampler (PAS) for monitoring the volatile emissions from dredged material placed in confined disposal facilities (CDF). Laboratory evaluations were used to assess the uptake kinetics, average equilibrium time, and estimate the POM-air partition coefficients (KPOM₋A) of 16 PCB congeners. The uptake kinetics defined the effective averaging time for air sampling and ranged from about a week for dichlorobiphenyls to 2 weeks or more for tetra- and pentachlorobiphenyls at ∼20 °C under internal mass transfer resistance control which was applicable for Log KPOM₋A < 8. The measured Log KPOM₋A for PCBs ranged from 5.65 to 9.34 and exhibited an average deviation of 0.19 log unit from the theoretical value of KPOM₋W/KAW. The PAS approach was then tested with a preliminary field application (n = 17) at a CDF allowing equilibration over 42 days. The field application focused on lower congener PCBs as a result of the estimated increase in KPOM₋A and longer uptake times expected at the low ambient temperatures during the field study (average of 3.5 °C). Total PCB air concentrations around the CDF averaged 0.32 ng/m³ and varied according to proximity to placement of the dredged materials and predominant wind directions. Average PAS concentration of low congener number PCBs (15, 18, 20/28, 31) were compared to available high volume air sampler (HVAS) measurements. The PAS concentrations were within 20% of HVAS in the dominant north and south directions and showed similar trends as east and west HVAS samplers although PAS concentrations were as much as an order of magnitude below the west HVAS.
Show more [+] Less [-]Arctic snow pollution: A GC-HRMS case study of Franz Joseph Land archipelago Full text
2020
Mazur, D.M. | Latkin, T.B. | Kosyakov, D.S. | Kozhevnikov, AYu | Ul’yanovskii, N.V. | Kirilov, A.G. | Lebedev, A.T.
Anthropogenic pollution of the Arctic atmosphere is of great interest due to the vulnerability of the Arctic ecosystems, as well as the processes of global transport and accumulation of atmospheric aerosols at high latitudes under conditions of cold climate. The present work throws light upon chemical composition of Arctic snow as a natural deposition matrix for atmospheric semi-volatile pollutants taken from the northernmost Arctic archipelago - Franz Josef Land, which is least affected by local sources of pollution and being a unique unstudied environmental object. The used methodology involved the liquid-liquid extraction of snow samples with dichloromethane and combination of targeted and non-targeted analyses of semi-volatile organic compounds with comprehensive two-dimensional gas chromatography – high-resolution mass spectrometry. While almost none of the known priority pollutants (except three dialkylphthalates) were identified in the studied samples, non-targeted screening revealed a specific class of biomass burning biomarkers – fatty amides with oleamide being the major component among them. Some peculiar organic pollutants (N,N-dimethylcyclohexylamine and N,N-dimethylbenzylamine) were identified in few samples.First results on the semi volatile pollutants in Franz Joseph Land snow were obtained using the most reliable GC × GC-HRMS non-target analysis.
Show more [+] Less [-]Toxic effects and transcriptome analyses of zebrafish (Danio rerio) larvae exposed to benzophenones Full text
2020
Meng, Qi | Yeung, Karen | Kwok, Man Long | Chung, Chun Ting | Hu, Xue Lei | Chan, King Ming
Sunscreen chemicals, such as benzophenones (BPs), are common environmental contaminants that are posing a growing health concern due to their increasing presence in water, fish, and human systems. Benzoresorcinol (BP1), oxybenzone (BP3), and dioxybenzone (BP8) are the most commonly used BPs for their ability to protect from sunburn by absorbing a broad spectrum of ultraviolet radiation. In this study, zebrafish larvae were used as an in vivo model to investigate the potential risks and molecular mechanisms of the toxic effects of BPs. The effects of these BPs on the gene expression in the aryl hydrocarbon receptor pathway, estrogen receptor pathway, and sex differentiation were detected using quantitative real-time PCR. All BPs were found to function as agonists of the estrogen receptors α and β1, indicating that these BPs likely undergo similar molecular metabolism in vivo, whereby they can activate cytochrome P450 genes and promote the expression of CYP19A and DMRT1. Furthermore, the gene expression profile of larvae after BP3 exposure was evaluated using a whole transcriptome sequencing approach. BP3 affected estradiol biosynthesis and sex differentiation. It also regulated gonadotropin-releasing hormone, thus interfering with the endocrine system. As a xenobiotic toxicant, BP3 upregulated the expression of cytochrome P450 genes (CYP1A and CYP3A65) and glutathione metabolism-related genes (GSTA, GSTM, and GSTP). It also interfered with the nervous system by regulating the calcium signaling pathway. These findings will be useful for understanding the toxicity mechanisms and metabolism of BPs in aquatic organisms and promote the regulation of these chemicals in the environment.
Show more [+] Less [-]Antimicrobial resistance in freshwater Plesiomonas shigelloides isolates: Implications for environmental pollution and risk assessment Full text
2020
Ekundayo, Temitope Cyrus | Okoh, Anthony I.
Antibiotic resistance is known to impact treatment efficiency of Plesiomonas infections negatively with fatal outcomes. This study investigated antibiogram fingerprint of P. shigelloides (n = 182) isolated from three South Africa rivers using the disc diffusion technique. Environmental pollution and analogous health risk (given infections) that could associate with the freshwaters and empirical treatment of Plesiomonas were assessed using Antibiotic Resistance Index (ARI) and Multiple Antibiotic Resistance Indices (MARI), respectively. Thirteen EUCAST recommended (ERAs) and eleven non-recommended antibiotics (NAs) used as first line agents in the treatment of gastroenteritis and extraintestinal infections were tested. Resistance against ERAs decreased from cefoxitin (37.91%), cefuroxime (35.17%), cefepime (31.87%), ceftriaxone (29.67%), ciprofloxacin (18.13%), trimethoprim-sulfamethoxazole (10.44%), piperacillin/tazobactam (8.79%), ertapenem (4.95%), norfloxacin (4.40%), levofloxacin (2.75%), meropenem (1.10%) to imipenem (0.55%). The isolates had higher resistance (≥36.07%) against NAs but were susceptible to amikacin (67.58%), gentamycin (73.08%), and tetracycline (80.77%). MARI of the isolates were significantly different between ERAs and NAs (P-value < 0.05) and had an average of 0.17 ± 0.18 and 0.45 ± 0.13, respectively. About 33.87% and 95.63% of the isolates had MARI value from 0.23 to 0.62 and 0.27–0.82 to ERAs and NAs, respectively. Also, ERAs-based and NAs-based ARI across sampling units showed significantly different (P-value < 0.05) means of 0.18 ± 0.09 and 0.46 ± 0.05, respectively. MARI attributed low risk of empirical treatment to recommended antibiotics but higher risk to non-recommended antibiotics. Model estimated successful and unsuccessful empirical treatment of infections risks due to resistance in the isolates using recommended antibiotics as 65.93% and 34.07%, respectively; 1.65% and 98.35% in the case of non-recommended antibiotics, respectively. ARI based on recommended antibiotics identified potential environmental pollutions in a number of sites. Resistance in freshwater P. shigelloides especially against cephalosporin, quinolones and fluoroquinolones is distressing and might suggests high pollution of the freshwaters in the Eastern Cape Province.
Show more [+] Less [-]Does microplastic ingestion by zooplankton affect predator-prey interactions? An experimental study on larviphagy Full text
2020
Van Colen, Carl | Vanhove, Brecht | Diem, Anna | Moens, Tom
Litter is omnipresent in the ocean where it can be ingested by marine biota. Although ingestion of microplastics (MPs) is abundantly reported, insights into how MP can influence predator-prey interactions currently limits our understanding of the ecological impact of MPs. Here we demonstrate trophic transfer of MPs from zooplankton to benthic filter feeders, through consumption of contaminated prey (i.e. prey with ingested MP). However, predation rates of contaminated prey were significantly lower as compared to predation rates of prey that had no MPs ingested. As filter feeder clearance rates were not affected by consumption of MPs, the lower predation rates of contaminated prey appear to be primarily explained by disruption in zooplankton swimming behaviour that reduces their filtration risk. This is the first study that shows how MPs can change predator-prey interactions that are involved in the coupling between the pelagic and seabed habitat.
Show more [+] Less [-]PM2.5 and O3 pollution during 2015–2019 over 367 Chinese cities: Spatiotemporal variations, meteorological and topographical impacts Full text
2020
Zhao, Suping | Yin, Daiying | Yu, Ye | Kang, Shichang | Qin, Dahe | Dong, Longxiang
The strict Clean Air Action Plan has been in place by central and local government in China since 2013 to alleviate haze pollution. In response to implementation of the Plan, daytime PM₂.₅ (particulate matter with aerodynamic diameter less than 2.5 μm) showed significant downward trends from 2015 to 2019, with the largest reduction during spring and winter in the North China Plain. Unlike PM₂.₅, O₃ (ozone) showed a general increasing trend, reaching 29.7 μg m⁻³ on summer afternoons. Increased O₃ and reduced PM₂.₅ simultaneously occurred in more than half of Chinese cities, increasing to approximately three-fourths in summer. Declining trends in both PM₂.₅ and O₃ occurred in only a few cities, varying from 19.1% of cities in summer to 33.7% in fall. Meteorological variables helped to decrease PM₂.₅ and O₃ in some cities and increase PM₂.₅ and O₃ in others, which is closely related to terrain. High wind speed and 24 h changing pressure favored PM₂.₅ dispersion and dilution, especially in winter in southern China. However, O₃ was mainly affected by 24 h maximum temperature over most cities. Soil temperature was found to be a key factor modulating air pollution. Its impact on PM₂.₅ concentrations depended largely on soil depth and seasons; spring and fall soil temperature at 80 cm below the surface had largely negative impacts. Compared with PM₂.₅, O₃ was more significantly affected by soil temperature, with the largest impact at 20 cm below the surface and with less seasonal variation.
Show more [+] Less [-]Enhancing the plants growth and arsenic uptake from soil using arsenite-oxidizing bacteria Full text
2020
Debiec-Andrzejewska, Klaudia | Krucon, Tomasz | Piatkowska, Katarzyna | Drewniak, Łukasz
Plants, that naturally inhabit arsenic-contaminated areas may be used for effective arsenic-uptake from soil. The efficiency of this process may be increased by the reducing arsenic phytotoxicity and stimulating the activity of indigenous soil microbiota. As we showed, it can be achieved by the bioaugmenting of soil with arsenite-oxidizing bacteria (AOB). This study aimed to investigate the influence of soil bioaugmentation with AOB on the structure, quantity, and activity of the indigenous soil microbiota as well as to estimate the effect of such changes on the morphology, growth rate, and arsenic-uptake efficiency of plants. Plants-microbes interactions were investigated using the effective arsenites oxidizer Ensifer sp. M14 and the native plant alfalfa. The experiments were performed both in potted garden soil enriched with arsenic and in highly arsenic polluted, natural soil. The presence of M14 strain in soil contributed to the increase both in plants growth intensity and arsenic-uptake efficiency with regard to the soil without M14. After 40 days of plants culture, their average biomass increased by about 60% compared to non-bioaugmented soil, while the arsenic accumulation increased more than two times. The soil bioaugmentation contributed also to the increase in the quantity and activity of soil microorganisms without disturbing the natural microbial community structure. In the bioaugmented soil, the noticable increase in the quantity of heterotrophic, denitrifying, nitrifying and cellulolytic bacteria as well as in the activity of dehydrogenases and cellulases were observed. Soil bioaugmentation with M14 enables the application of native and commonly occurring plant species for enhancing the treatment of arsenic-contaminated soil. This in situ strategy may constitute a valuable alternative both to the chemical and physical methods of arsenic removal from soil and to the biological ways based on the arsenic hyperaccumulating plants and/or the arsenic mobilizing bacteria.
Show more [+] Less [-]Evaporation rates and pollutants emission from heated cooking oils and influencing factors Full text
2020
Adeniran, Jamiu Adetayo | Yusuf, Rafiu Olasunkanmi | Abdulkadir, Mariam Oyinkansola | Yusuf, Muhammad-Najeeb O. | Abdulraheem, Khadija Abdulkareem | Adeoye, Babatunde Kazeem | Sonibare, Jacob Ademola | Du, Mingxi
The heating of edible oils during cooking activities promotes the emissions of pollutants that have adverse impacts on the health of humans. This study investigated the evaporative emissions of fifteen (15) commonly used cooking oils. Split-plot experimental design under the response surface methodology framework was used to study singular and interaction effects of influencing parameters (temperature, volume of cooking oil and time) on cooking oil evaporation rate and pollutants emissions (i.e. Particulate matter of aerodynamic diameter ≤1 μm (PM₁.₀); ≤2.5 μm (PM₂.₅); ≤10 μm (PM₁₀); Total Suspended Particulate (TSP); Total Volatile Organic Compounds -TVOCs, and Carbon Monoxide- CO) on a groundnut oil sample that served as a case study. Obtained values of density, viscosity, kinematic viscosity, smoke, flash and fire points were; 873–917 kg/m³; 1.12–9.7 kg/ms; 2.4–3.4 m²/s; 96 -100 °C; 124–179 °C and 142–186 °C, respectively. The role of temperature as the most significant parameter influencing the rate of evaporative emissions was established. Evaporation rate and pollutants emission from unrefined samples were the highest. The restricted maximum likelihood (REML) analysis results suggested a strong relationship between the actual values and the predicted values as R-squared values obtained were greater than 0.8 for all the responses. These results suggest that minimal rates of evaporation and pollutants emission from heating cooking oils can be achieved with a high volume of the cooking oil at moderate temperature levels.
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