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Insecticide and metal exposures are associated with a surrogate biomarker for non-alcoholic fatty liver disease in the National Health and Nutrition Examination Survey 2003–2004 Texte intégral
2020
Wahlang, Banrida | Appana, Savitri | Falkner, K Cameron | McClain, Craig J. | Brock, Guy | Cave, Matthew C.
Non-alcoholic fatty liver disease (NAFLD), the most common form of liver disease, affects over 30% of the US population. Our group and others have previously demonstrated that low-level environmental pollutant exposures were associated with increased odds ratios for unexplained alanine aminotransferase (ALT) elevation, a surrogate biomarker for NAFLD, in the adult National Health and Nutrition Examination Survey (NHANES). However, recently, more sensitive and lower ALT cutoffs have been proposed. The objective of this observational study is to utilize these ALT cutoffs to determine new associations between environmental chemicals and the surrogate NAFLD biomarker. Adult NHANES 2003–2004 participants without viral hepatitis, hemochromatosis, or alcoholic liver disease were analyzed in this cross-sectional study. ALT elevation was defined as > 30 IU/L in men and > 19 IU/L in women. Odds ratios adjusted for potential confounders for ALT elevation were determined across exposure quartiles for 17 pollutant subclasses comprised of 111 individual pollutants. The overall prevalence of ALT elevation was 37.6%. Heavy metal and organochlorine insecticide subclasses were associated with dose-dependent increased adjusted odds ratios for ALT elevation of 1.6 (95% CI 1.2–2.3) and 3.5 (95% CI 2.3–5.5) respectively, for the highest vs. lowest exposure quartiles (pₜᵣₑₙd < 0.01). Within these subclasses, increasing whole blood levels of lead and mercury, and lipid-adjusted serum levels of dieldrin, and the chlordane metabolites, heptachlor epoxide, and trans-nonachlor, were associated with increased odds ratios for ALT elevation. In conclusion, organochlorine insecticide, lead, and mercury exposures were associated with ALT elevation and suspected NAFLD in adult NHANES 2003–2004.
Afficher plus [+] Moins [-]Seasonal changes in groundwater quality deterioration and chemometric analysis of pollution source identification in South India Texte intégral
2020
Vasanthakumari Sivasankara Pillai, Adithya | Sabarathinam, Chidambaram | Keesari, Tirumalesh | Chandrasekar, Thivya | Rajendiran, Thilagavathi | Senapathi, Venkatramanan | Viswanathan, Prasanna Mohan | Samayamanthu, Dhanu Radha
Hydrogeochemical understanding of groundwater is essential for the effective management of groundwater. This study has been carried out to have concrete data for the seasonal variations in hydrogeochemistry of groundwater in central Tamilnadu forming a complex geological terrain with a varied lithology. A total of 244 groundwater samples were collected during four different seasons, viz, southwest monsoon (SWM), summer (SUM), postmonsoon (POM), and northeast monsoon (NEM) from bore wells. The physical parameters such as pH, temperature, TDS, ORP, humidity, and electrical conductivity (EC) were measured insitu, whereas major ions were analyzed in the lab adopting standard procedures. Overall, higher EC and NO₃ values were observed and exceeded the WHO permissible limit irrespective of seasons, except for NO₃ in SWM. Na and HCO₃ are the dominant cation and anion in the groundwater irrespective of seasons. The highest average values of Na (65.06 mg L⁻¹) and HCO₃ (350.75 mg L⁻¹) were noted during SWM. Statistical analysis was carried out to elucidate the hydrogeochemistry of the region. Initially, to understand the ionic relationship, correlation matrix was used followed by factor analysis for determination of major geochemical control and later factor scores were derived to understand the regional representations. An attempt has also been made to identify the samples influenced by multiple geochemical processes and to understand their spatial variation in the study period. Correlation of geochemical parameters reveals a excellent positive correlation between Ca and NO₃ in SUM, SWM, and NEM due to the dominant of anthropogenic sources and minor influence of weathering process. Strongly loaded factor scores are found to be mostly in the following order POM > NEM > SWM > SUM. Principal component analysis of different seasons indicates the interplay of natural weathering and anthropogenic factors. Overall, the predominant geochemical processes in this region, irrespective of seasons are weathering and, ion exchange and anthropogenic activities.
Afficher plus [+] Moins [-]Adulticidal activities of Cymbopogon citratus (Stapf.) and Eucalyptus globulus (Labill.) essential oils and of their synergistic combinations against Aedes aegypti (L.), Aedes albopictus (Skuse), and Musca domestica (L.) Texte intégral
2020
Soonwera, Mayura | Sittichok, Sirawut
The knockdown and adulticidal activities of individual Cymbopogon citratus and Eucalyptus globulus essential oils (EOs) and their combinations were evaluated against three medical insect pests (Aedes aegypti, Aedes albopictus, and Musca domestica) using a WHO susceptibility test. The knockdown and adulticidal activities against the three medical insect pests of combinations of C. citratus and E. globulus EOs were higher than those of individual EOs alone. Combinations of 7.5% C. citratus + 7.5% E. globulus EOs and 10% C. citratus + 10% E. globulus EOs exhibited the highest efficacy against females of the three species with 100% knockdown and mortality rates at 1 and 24 h after exposure, respectively. Their adulticidal activities were equivalent to that of 10% w/v cypermethrin. In contrast, 70% v/v ethyl alcohol negative control was not effective at all. The combinations of EOs showed a synergistic effect, i.e., their adulticidal activity was improved by 0.2 to 100%, with increased knockdown and mortality rates, compared to individual EOs. The highest synergistic effect on effective knockdown and adulticidal activities against females of the three species was achieved by a combination of 2.5% C. citratus + 2.5% E. globulus EOs, with 36.6 to 100% knockdown rate increase and 33.5 to 98.9% mortality rate increase. This study demonstrates that all tested combinations of C. citratus and E. globulus EOs were effective adulticidal agents against females of Ae. aegypti, Ae. albopictus, and M. domestica and have a high potential for development into a botanical insecticide for controlling populations of Aedes mosquitoes and houseflies.
Afficher plus [+] Moins [-]National screening study investigating nine phthalates and one adipate in raw and treated tap water in France Texte intégral
2020
Bach, Christina | Rosin, Christophe | Munoz, Jean-François | Dauchy, Xavier
The goal of this study was to determine the potential exposure of much of the French population to nine phthalates and bis (2-ethylhexyl) adipate (DEHA) due to water consumption. The occurrence of these compounds was investigated in raw and treated water from public water systems. Water samples were collected in one sampling campaign equally distributed across 101 French départements (a French administrative unit) from November 2015 to July 2016. In all, 271 raw water samples and 283 treated water samples were collected. A specific sampling protocol was conducted in order to assess phthalate pollution during sampling and analysis, and to produce reliable results. Field blanks were thus collected at the same time as real samples at each sampling point. The contamination detected in field blanks was due to diethyl phthalate (DEP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), and di-2-ethylhexyl phthalate (DEHP), which are common phthalate interferences in blanks. Their concentrations were never ten times higher than the limits of quantification (LOQ). In tap water, the most frequently detected compound was DBP, at a maximum concentration of 1300 ng/L. In raw water, however, DEP was the most frequently detected analyte with concentrations ranging from 255 to 406 ng/L, while DIBP was observed at a maximum concentration of 1650 ng/L. It is worth mentioning that DEHP—the most widely used phthalate—was only detected in one sample of raw water. Phthalates are not concentrated in any particular area of France in either raw or treated water.
Afficher plus [+] Moins [-]Effects of biochar properties on the bioremediation of the petroleum-contaminated soil from a shale-gas field Texte intégral
2020
Ren, Hong-Yang | Wei, Zi-Jing | Wang, Yan | Deng, Yuan-Peng | Li, Mingyou | Wang, Bing
The characteristics of biochar carriers prepared from different biomass (corncob, straw, and sawdust) were investigated, and the bioremediation performance of the biochar through microbial immobilization was analyzed. Corncob biochar had the highest specific surface area (157.11–312.30 m² g⁻¹) among the different biomass, and the specific surface area and total pore volume reached the maximum at 500 °C. The pore size was primarily micropore, which aided to the fixation of microorganisms and the adsorption of petroleum pollutants. With increased pyrolysis temperature, the polar functional groups in biochar decreased, and the aromatic functional groups gradually increased, thereby benefiting the adsorption of hydrophobic organic compounds. Corncob biochar had the highest zeta potential, i.e., from − 30.95 to − 6.43 mV, conducive to the electrostatic adsorption between carrier and microorganism. The highest oil-removal and microbial-immobilization rates of biochar CC500 (with corncob pyrolyzed at 500 °C) were about 70.7% and 71.2%, respectively. A strong recovery of microbial growth activity was also observed; recovery was 83.38% compared with free bacteria, and the fixed microorganisms reached logarithmic-growth period at 8–18 h.
Afficher plus [+] Moins [-]Using golden apple snail to mitigate its invasion and improve soil quality: a biocontrol approach Texte intégral
2020
Wang, Jiaxin | Lu, Xuening | Zhang, Jiaen | Ouyang, Ying | Qin, Zhong | Zhao, Benliang
The invasive and widespread golden apple snail (GAS, Pomacea canaliculata) is a harmful crop pest in many parts of Asia. The heavy use of molluscicides to control GAS could result in soil and water pollution as well as in loss of biodiversity. A sustainable and pollution-free control method is urgently needed to counteract this invasion. In this study, we proposed using dried and powdered GAS residue to neutralize and fertilize soils. We compared the effects of adding GAS residue (i.e., ground GAS shell and meat residue) to the effects of adding lime upon soil properties and microbes in a greenhouse pot experiment. Each pot was incubated for 120 days, and soil pH, nutrients, microbial species, and enzyme activity were assessed. Results showed that addition of GAS residue significantly improved soil pH, contents of total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), and available nitrogen but decreased soil available phosphorus (AP) content due to phosphorus sorption induced by soil organic matter (OM) and high pH. The GAS residue added to soil released nutrients and alleviated soil acidity, as well as provided more resources to soil microbes to increase their bioactivity, although lime addition was better at mitigating soil acidity. We found that with added GAS residue of 25 g kg⁻¹, the soil nitrate nitrogen (NO₃-N) content increased by 10 times; microbial biomass increased by 43%; and enzyme activity of β-1,4-glucosidase, β-1,4-N-acetylglucosaminidase, and β-D-cellobiosidase also were enhanced, compared to the control. Our findings suggest that GAS residue functions well as a fertilizer and soil amendment to aid the remediation of barren and acidic soils, making it a valuable and useful option in the control of the invasive GAS.
Afficher plus [+] Moins [-]Synthesis and characterization of high-performance activated carbon from walnut shell biomass for CO2 capture Texte intégral
2020
Al Mesfer, Mohammed K.
An increasing level of carbon dioxide (CO₂) in the atmosphere has ultimately resulted in global warming and climate change. The high-performance activated carbon (AC-WL) was synthesized from walnut shell, a low-cost biomass by-product, by physical activation using a tube furnace. The adsorption behavior of CO₂ from the CO₂/N₂ mixture was investigated using a fixed bed. The surface and morphological characterizations of the produced activated carbons were measured using a BET analyzer and a scanning electron microscope (SEM). The effect of temperature, flow rate, CO₂ level, and partial pressure on breakthrough behavior was analyzed, and the adsorption response presented in terms of breakthrough point and adsorption capacity. The breakthrough and saturation periods vary significantly with change in temperature. The steepness of the breakthrough curves signifies good utilization of adsorbent capacity at breakthrough point. The increase in temperatures and flow rates lead to an increase in the length of mass transfer zone. The adsorption capacity of 1.58 mmol/g was obtained at 1.30 bars and 293 K with higher capacity utilization factor of 0.8492.These results suggest that the walnut-based activated carbon is favorable for capturing CO₂.
Afficher plus [+] Moins [-]Short stay, long impact: ecological footprints of sojourners Texte intégral
2020
Ye, Qing | Anwar, Muhammad Azfar | Zhou, Rongting | Asmi, Fahad | Ahmad, Intikhab
The study proposes an empirical model (based on stimulus-organism-response as conceptual framework) to analyse sojourners’ intention to adopt green practices (i.e., electronic consumption behaviour). Specifically, the proposed model comprises ethical, ecological and economic concerns as stimuli while mapping sojourners’ altruistic traits and beliefs in climate change, which further lead to their green behaviour. The study investigates a sample of 1184 sojourners in China. Results highlight that sojourners’ perceived concerns (stimuli) are partially mediated by sojourners’ altruistic traits and beliefs in climate change while defining their green behaviour. The novel contributions of the current study include determining sojourners’ green behaviour, the role of scientific literacy and regulatory policy in green behaviour and generalising and proposing the concept of sojourner leakage (adapted from tourism leakage). The study emphasises that sojourners can be strategic stakeholders by involving them in designing, implementing and communicating green policies and reforms in diverse societies.
Afficher plus [+] Moins [-]Identify the significant contributors of regional CO2 emissions in the context of the operation of high-speed railway—illustrated by the case of Hunan Province Texte intégral
2020
Gan, Mi | Jiang, Qingchen | Zhu, Daoli
High-speed rail (HSR) is one of the essential innovations in the field of transportation in the latter half of the twentieth century. In China, the rapid development of HSR has received increasing attention and resulted in a boost of tourism, with significant impact on the development of cities that operates HSR. To accurately comprehend how will the operation of HSR influence the regional CO₂ emissions, this paper applies the modified STIRPAT model, combining with real data on high-speed rail passenger flow volume of the Beijing-Guangzhou high-speed rail Hunan section. The results show that (1) the high-speed rail operation is also a significant impact factor for regional CO₂ emissions. (2) Considering the operation of HSR, the ranking of contribution rate of driving factors for regional CO₂ emissions is as follows: GDP per capita, energy consumption per unit of GDP, arrival volume of high-speed rail, originated volume of high-speed rail, the proportion of coal in the energy mix, proportion of the tertiary industry, and population. (3) Surprisingly, the numerical research result shows that the operation of HSR for the cities may promote regional CO₂ emissions, while the increase in urban population and the optimization of energy structure have a reducing effect on regional carbon emissions. There is a transfer effect of the operation of HSR and region development, which results in the rising of regional CO₂ emissions. Thus, it is urgent to research on the decoupling of economic growth from CO₂ emissions. The findings could be conducive for the government and railway company to evaluate and administrate the operation of high-speed rail and adequately deal with the relationships between the high-speed railway and regional development.
Afficher plus [+] Moins [-]Veterinary growth promoters in cattle feedlot runoff: estrogenic activity and potential effects on the rat male reproductive system Texte intégral
2020
Patrick, Sean Mark | Aneck-Hahn, Natalie Hildegard | Van Wyk, Susan | Van Zijl, Magdelena Catherina | Huma, Mampedi | De Jager, C. (Tiaan)
The contribution of veterinary growth promoters (VGP) to the environmental burden of endocrine-disrupting chemicals (EDCs) is largely unknown. At cattle feedlots, the excrement of cattle may contain VGPs, which can contaminate aquatic systems and pose reproductive health risks. The study identifies VGPs used at cattle feedlots in South Africa and confirms associated estrogenic activity in feedlot runoff water. Using a rat model, we investigate the potential reproductive health effects and thyroid function of an environmentally relevant mixture of VGPs. Collected water samples had low levels of selected VGPs, and estrogenic activity was detected in the T47D-KBluc bioassay. Rats exposed to VGP had significant adverse effects on male reproductive health, including shortened anogenital distance, lowered sperm counts, disorganized seminiferous tubules, and thyroid parameters. In conclusion, VGP can contribute to complex environmental EDC mixtures and may adversely affect the reproductive and thyroid health of both humans and wildlife. The varied topography of individual cattle feedlots will govern the rate and extent of effluent runoff, thus continuous monitoring of VGPs in aquatic systems surrounding cattle feedlots is necessary.
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