https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50203 Wed 28 Feb 2024 16:02:09 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51944 MTC) was considered as the dependent variable; bioavailable As (BAs), total As (TAs), pH, organic carbon (OC), available phosphorus (AvP), and available iron (AvFe) were the predictor variables. LR performed better than RF and GBM in terms of accuracy, sensitivity, specificity, kappa, precision, log loss, F1score, and MCC. From the better-performing LR model, bioavailable As (BAs), TAs, AvFe, and OC were significant variables for grain As. From the partial dependence plots (PDP) and individual conditional expectation (ICE) of the LR model, 5.70 mg kg−1 was estimated to be the limit for BAs in soil.]]> Wed 28 Feb 2024 15:34:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34228 Wed 20 Feb 2019 15:55:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48921 Wed 19 Apr 2023 15:56:22 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31152 2) were obtained for Tympanotonus fuscatus, suggesting the potential for non-carcinogenic health outcomes in adults after a prolonged period of consumption. This calls for continuous monitoring and enforcement of regulations to ensure safety of fishery resources from Lagos Lagoon.]]> Wed 17 Nov 2021 16:30:33 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37162 Wed 17 Nov 2021 16:29:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30718 n = 162) with the highest fraction being 98.6%. The daily intake of inorganic As from rice ranged between 0.38 and 1.92 µg/kg BW in different districts. The incremental lifetime cancer risk (ILCR) for individuals due to the consumption of rice varied between 0.57 × 10^-3 to 2.88 × 10^-3 in different districts, and 0.54 × 10^-3 to 2.12 × 10 ^-3 in different varieties, higher than the US EPA thresho ld. The 2-10 age group experiences higher carcinogenic risks than others and females are more susceptible than males.]]> Wed 15 Dec 2021 16:10:48 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37835 80% of the total inorganic As in pore water and total As concentration declined from 933 μg/L to 177 μg/L with time. AWD irrigation practice with Si fertilization significantly reduced the total As levels in pore water. Arsenic concentration in different rice plant tissues showed significant variations due to water and fertilizer management. Lower concentrations of As in rice grains were observed using AWD (average 93.0 μg/kg) than those observed in CF (average 121 μg/kg) irrigation practice. The addition of Si also significantly (p < 0.03) decreased As uptake by rice plants while adding of P has no significant effect and this is also true for Si and P interaction. AWD irrigation practice with Si fertilization resulted in a reduction of grain As level at around 12%–21%, while grain yield increased by 13%.]]> Wed 12 May 2021 15:22:37 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50272 Wed 12 Jul 2023 14:11:21 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26286 -1 (range = 1.5-201 µg·L^-1). Fifty three percent groundwater samples showed higher As value than WHO safe limit of 10 µg·L^-1. Speciation of As in groundwater samples (n = 13) showed the presence of inorganic As only; arsenite (As(III)) constituted 13%-67% of total As and arsenate (As(V)) ranged from 33% to 100%. For As health risk assessment, the hazard quotient and cancer risk values were 11-18 and 46-600 times higher than the recommended values of US-EPA (i.e., 1.00 and 10^-6, respectively). In addition to As, various water quality parameters (e.g., electrical conductivity, Na, Ca, Cl¯, NO₃¯, SO₄²¯, Fe, Mn, Pb) also enhanced the health risk. The results show that consumption of As-contaminated groundwater poses an emerging health threat to the communities in the study area, and hence needs urgent remedial and management measures.]]> Wed 11 Apr 2018 15:52:32 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3288 Wed 11 Apr 2018 13:40:06 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:11102 50 μg/L) through drinking water also increases the risk of adverse pregnancy outcomes. The synergistic effects (if any) of malnutrition and chronic arsenic exposure may worsen the adverse pregnancy outcomes. This population based case control study reports the association between chronic arsenic exposure and nutritional status among the rural women in Bangladesh. 348 cases (BMI < 18.5) and 360 controls (BMI 18.5–24.99) were recruited from a baseline survey conducted among 2,341 women. An excess risk for malnutrition was observed among the participants chronically exposed to higher concentrations of arsenic in drinking water after adjusting for potential confounders such as participant’s age, religion, education, monthly household income and history of oral contraceptive pills.Women exposed to arsenic >50 μg/L were at 1.9 times (Odds Ratio = 1.9, 95% CI = 1.1–3.6) increased risk of malnutrition compared to unexposed. The findings of this study suggest that chronic arsenic exposure is likely to contribute to poor nutritional status among women of 20–45 years.]]> Wed 11 Apr 2018 12:51:48 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:7983 Wed 11 Apr 2018 09:44:54 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:16780 Wed 11 Apr 2018 09:14:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30719 in vivo assay using swine was used to measure the absolute bioavailability (AB) of As from cooked rice of twelve genotypes commonly grown in Bangladesh. An assessment of both total As in rice and its bioavailability is crucial for estimating human exposure following dietary intake by the local community. Average As concentrations in each rice genotype ranged from 108 ± 4 μg/kg to 580 ± 6 μg/kg. Arsenic speciation shows that most of the rice genotype contains 73 to 100% inorganic As. Swine were administered with As orally and via intravenous method, i.e. injection and fed certain common Bangladeshi rice genotypes (cooked). Swine blood As levels were measured to calculate As bioavailability from rice. Pilot studies shows that for As(III) and As(V), 90.8 ± 12.4% and 85.0 ± 19.2% of the administered oral dose was absorbed from the gastrointestinal tract whereas organic As was poorly absorbed resulting in low bioavailability values 20.2 ± 2.6% (MMA) to 31.2 ± 3.4% (DMA), respectively. These studies demonstrates that rice genotypic characters influenced As bioavailability in rice grown in As-contaminated areas and the bioavailability varied between 25% and 94%. Arsenic in salt tolerant rice genotypes Binadhan-10 and BRRI dhan47 as well as brown rice genotypes Kheali Boro and Local Boro has lower bioavailability (< 50%) compared to other rice genotypes. The most commonly cultivated and consumed variety (BRRI dhan28) has As bioavailability of 70%, which poses a significant risk to consumers. Calculation of maximum tolerable daily intake (MTDI) for humans due to consumption of rice based on bioavailability data was higher than those calculated based on inorganic and organic As concentration in rice genotypes.]]> Wed 06 Apr 2022 14:04:20 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29507 Wed 06 Apr 2022 13:59:57 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29583  L28 > C1. Strains AB3, C31, and L28 accumulated higher levels of intracellular vitamin B12 than strain C1. However, only strain C1 produced SAM and showed As biovolatilization activity. When strain C1 was incubated under microaerobic light conditions, it produced arsenobetaine [(AsB(V)] in medium with As(III) and monomethylarsonic acid [MMA(V)] in medium with As(V), which were found in the culture supernatants. Volatile methylated As compounds, such as dimethylarsenic acid [DMA(V)] and MMA(V)], were also detected in strain C1 during 30 days of incubation with As(III) and As(V). Strains AB3, C1, and L28 were identified as Rhodopseudomonas palustris and strain C31 as Rubrivivax benzoatilyticus. The resistance of these strains to As [As(III) and As(V)] based on minimum inhibition concentration values under aerobic dark and microaerobic light conditions, respectively, was in the order of C1 > AB3 > C31 > L28. The overall results demonstrate that all four selected strains of PNSB have a great potential for future application in the remediation of As-contaminated areas although R. palustris C1 was the most effective candidate.]]> Tue 31 Jul 2018 16:28:15 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51254 Tue 29 Aug 2023 10:47:01 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20106 50μg/L or to that of arsenic exposure as quartiles or as duration. Arsenic concentration as quartiles and >50 μg/L did show a strong relationship with increased pulse pressure (adjusted OR: 3.54, 95% CI: 1.46–8.57), as did arsenic exposure for ≥10 years (adjusted OR: 5.25, 95% CI: 1.41–19.51). Arsenic as quartiles showed a dose response relationship with increased pulse pressure. Our study suggests an association between higher drinking water arsenic or duration and pulse pressure, but not hypertension.]]> Tue 24 Aug 2021 14:26:19 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46340 −1 (Bangladesh drinking water standard) during pre-monsoon, while 11 samples out of 20 were unable to remove As below the WHO provisional guideline value of 10 µg L⁻¹. During post-monsoon, none of the samples exceeded 50 µg L−1, but eight of them exceeded 10 µg L⁻¹. The Fe removal efficiencies of AIRPs were evident in more than 80% samples. Although As removal efficiency was found to be substantial, a cancer risk assessment indicates that hazard quotient (HQ) and carcinogenic risk (CR) of As in treated water for adults and children are above the threshold limits. Thus, additional reductions of As concentrations in treated water are needed to further reduce the excess cancer risk due to As in drinking water. Since 55% and 40% of the AIRPs were unable to remove As < 10 µg L⁻¹ during pre-monsoon and post-monsoon, further improvement including changes in AIRP design, regular cleaning of sludge, and periodic monitoring of water quality are suggested. Future research is needed to determine whether these modifications improve the performance of AIRPs.]]> Tue 15 Nov 2022 15:04:48 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47014 Tue 13 Dec 2022 11:48:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46989 Tue 13 Dec 2022 09:35:23 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51455 Tue 05 Sep 2023 18:15:02 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30619 -1 dry weight) did not exceed the Canadian Interim Sediment Quality Guideline (CISQG) value of 7.24 mg kg^-1 dry weight during the wet and dry seasons. Based on the Sediment Quality Guidelines (SQGs) of the United States Environmental Protection Agency (USEPA) and ecological risk assessment using the enrichment factor (EF), contamination factor (CF) and geo-accumulation index (I_geo), the study’s results indicate two things: firstly, low to moderate and significant levels of enrichment from As; and secondly, low to moderate degree of contamination in Lagos Lagoon during the study period.]]> Tue 03 Dec 2019 15:10:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50558 Tue 01 Aug 2023 10:33:02 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32391 Thu 28 Oct 2021 12:36:12 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39841 Thu 28 Jul 2022 10:57:07 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45315 1) and carcinogenic risks (CR > 1.010–4) while AWD lowered health risks compared to CF. Thus, rice farming using AWD irrigation could be a viable and long-term solution for reducing As contamination in rice and associated human health hazards.]]> Thu 27 Oct 2022 13:56:53 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36013 Thu 20 Feb 2020 11:35:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32335 Thu 14 Apr 2022 11:05:50 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24911 Thu 14 Apr 2022 11:05:18 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30107 Thu 14 Apr 2022 11:04:20 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29676 Thu 14 Apr 2022 11:03:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34661 10 μg/L (maximum concentration 3,700 μg/L). Chronic exposure to arsenic through drinking water causes various health problems, like dermal, neurological, reproductive and pregnancy effects, cardiovascular effects, diabetes mellitus, diseases of the respiratory and gastrointestinal systems, and cancers, typically involving the skin, lungs, liver, bladder, etc. About 4.5% of the 8,000 children from arsenic-affected villages of affected states were registered with mild to moderate arsenical skin lesions. In the preliminary survey, more than 10,000 patients were registered with different types of arsenic-related signs and symptoms, out of more than 100,000 people screened from affected states. Elevated levels of arsenic were also found in biological samples (urine, hair, nails) of the people living in affected states. The study reveals that the population who had severe arsenical skin lesions may suffer from multiple Bowens/cancers in the long term. Some unusual symptoms, such as burning sensation, skin itching and watering of eyes in the presence of sun light, were also noticed in arsenicosis patients.]]> Thu 14 Apr 2022 11:02:12 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32797 Thu 14 Apr 2022 11:01:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24840 Thu 14 Apr 2022 10:59:28 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35935 9882 groundwater samples) were used to describe As variability in groundwater of Pakistan and for comparison with global data. The mean groundwater As content reported in these studies was 120 µg/L (range: 0.1-2090 µg/L; SD: ±307). About 73% of the values for mean As contents in the 43 studies were higher than the World Health Organization (WHO) permissible limit (10 µg/L) for drinking water, while 41% were higher than the permissible limit of As in Pakistan (50 µg/L). It was observed that groundwater samples in some areas of Punjab and Sindh provinces contained high As concentrations which were almost equal to concentrations reported in the most contaminated areas of the world. We predicted that the mean values of ADD, HQ and CR were 4.4 µg kg^-1day^-1(range: 0-77 µg kg^-1day^-1), 14.7 (range: 0-256) and 0.0029 (range: 0-0.0512), respectively, based on mean As concentrations reported in Pakistan. In addition, this article proposes some integrated sustainable solutions and future perspectives keeping in view the regional and global context, as well as the on-ground reality of the population drinking As-contaminated water, planning issues, awareness among civil society and role of the government bodies. Based on available data, it is predicted that almost 47 million people in Pakistan are residing in areas where more than 50% of groundwater wells contain As concentrations above the WHO recommended limit of As in drinking water.]]> Thu 14 Apr 2022 10:59:13 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23232 . 1 for As in drinking water, vegetables and rice, for Mn in drinking water, vegetables, rice and wheat, for Pb in rice and wheat indicated the potential health risk to the local population. An assessment of As and other elements of other food components should be conducted to understand the actual health hazards caused by ingestion of food in people residing in the middle Gangetic plain.]]> Thu 14 Apr 2022 10:59:04 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30167 50 ppb) and spontaneous abortion, stillbirth and low birth weight. Limitations of certain studies include study design, small sample size, recall constraints and exposure assessment. There needs to be further research investigating the dose metered impact of arsenic exposure on pregnancy outcomes. Further research on impact of low–moderate arsenic concentration exposure on pregnancy outcomes will allow for appropriate public health policy recommendations.]]> Thu 14 Apr 2022 10:57:38 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42912 -1 and ∼33,000 to ∼150 μg L^-1, respectively. This trend was interrupted by a sharp rise in aqueous As(III) and Fe(II) caused by reductive dissolution of As-bearing Fe(III) phases in a sediment retention pond. Attenuation of Fe and As mobility occurred via formation of As(V)-rich schwertmannite, As(V)-rich jarosite, and amorphous ferric arsenate (AFA), resulting in solid-phase As concentrations spanning ∼13 to ∼208 g kg-1. Schwertmannite and jarosite retained As(V) predominantly by structural incorporation involving AsO₄-for-SO₄ substitution at up to ∼40 and ∼22 mol %, respectively. Arsenic strongly influenced Fe(III) mineral formation, with high As(V) concentrations causing formation of AFA over schwertmannite. Arsenic also strongly influenced Fe(III) mineral evolution over time. In particular, increasing levels of As(V) incorporation within schwertmannite were shown, for the first time, to enhance the transformation of schwertmannite to jarosite. This significant discovery necessitates a re-evaluation of the prevailing paradigm that As(V) retards schwertmannite transformation.]]> Thu 02 Nov 2023 14:53:12 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51866 Thu 02 Nov 2023 14:47:06 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42716 Thu 01 Sep 2022 11:33:23 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:31400 Cucumis sativa L) conducting 4 weeks pot study in 5 different soils spiked with As (0, 2, 4, 8 to 1024 mg kg_{-1 ) individually and with Zn at two phytotoxic doses. The As pore-water concentration was significantly reduced (df = 289, Adjusted R² = 0.84, p < 0.01) in the presence of Zn in the whole dataset, whereas Zn and Zn²⁺ activity in pore-water was reduced significantly only in the two alkaline soils. This outcome may be due to adsorption/surface precipitation or tertiary bridging complexation. No homogenous precipitation of zinc arsenate could be established using electron microscopy, XRD or even equilibrium calculations. For bioaccumulation phase, no significant effect of Zn on As uptake was observed except acidic MG soil whereas, Zn uptake was significantly reduced (p < 0.05) by As in whole dataset. However, an additive response was observed mostly except acidic MG soil. The synergistic response (more than additive) was predominant in this soil for a wide range of inhibition concentration (0¿80%) at both Zn EC10 and EC50 levels. Since additive response is mostly considered in risk assessment for mixtures, precautions should be implemented for assessment of toxicity for As-Zn mixture in acidic soil due to their synergistic response in some soils.]]>} Sat 24 Mar 2018 08:43:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:1552 Sat 24 Mar 2018 08:30:42 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:5053 Sat 24 Mar 2018 07:48:42 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29268 Sat 24 Mar 2018 07:39:17 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28139 −1). The objective was to understand how bioaccessible As by different methods was related to different As pools based on sequential extraction and 0.43 M HNO₃ extraction. Arsenic bioaccessibility was 7.6–25, 2.3–49, 7.3–44, and 1.3–38% in gastric phase (GP), and 5.7–53, 0.46–33, 2.3–42, and 0.86–43% in intestinal phase (IP) for UBM, SBRC, IVG, and PBET, respectively, with HNO₃-extractable As being 0.90–60%. Based on sequential extraction, As was primarily associated with amorphous (AF3; 17–79%) and crystallized Fe/Al oxides (CF4; 6.4–73%) while non-specifically sorbed (NS1), specifically sorbed (SS2), and residual fractions (RS5) were 0–10%, 3.4–20% and 3.2–25%. Significant correlation was found between As bioaccessibility by PBET and NS1 + SS2 (R² = 0.55 − 0.69), and UBM-GP and NS1 + SS2 + AF3 (R² = 0.58), indicating PBET mostly targeted As in NS1 + SS2 whereas UBM in NS1 + SS2 + AF3. HNO₃-extractable As was correlated to bioaccessible As by four methods (R² = 0.42 – 0.72) with SBRC-GP having the best correlation. The fact that different methods targeted different As fractions in soils suggested the importance of validation by animal test. Our data suggested that HNO₃ may have potential to determine bioaccessible As in soils.]]> Sat 24 Mar 2018 07:36:39 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30318 Sat 24 Mar 2018 07:31:51 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30887 Sat 24 Mar 2018 07:30:40 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29775 80%) samples found above BIS and WHO permissible limit, while 28% samples exceeded the previous WHO drinking water guideline (400 µg/L) for manganese (Mn). In dietary food grains As followed the sequence as rice > wheat > maize. The estimated daily intake by individual of As, Mn, Ni, Cd, Co, Pb, Zn and Cr from drinking water and dietary food grains were 169,14582, 474, 19, 26, 1449, 12955 and 882 µg/ kg. The Health Risk Index (HRI) were >1 for As in drinking water, vegetables and rice indicated the potential health risk to the residents of the study area. However, HRI <1 for wheat and maize indicate a relative absence of health risks associated with their ingestion.]]> Sat 24 Mar 2018 07:30:31 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28266 Sat 24 Mar 2018 07:28:35 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30613 −, toxic contaminants CN⁻ and AsO₃³⁻/AsO₄³⁻, and anionic fluorosurfactants. The anionic fluorosurfactants mainly include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), both of which have recently been listed as emerging contaminants and categorised as persistent organic pollutants. This review addresses recent advancements in the development of gold nanoparticle-based nano-sensors for such anions and outlines their performance limitations towards on-site applications.]]> Sat 24 Mar 2018 07:28:26 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:26318 V than As^III to L. disperma but was highly effective in reducing both the As^III and As^V toxicity to C. cf. dubia. The growth of Chlorella sp. was significantly higher (p<0.05) in remediated and pre-remediated water than in controls (non-As-contaminated filtered Colo River water) for As^III, while the opposite was observed for As^V, indicating that As^V is more toxic than As^III to this microalga. Although the IOCS can efficiently remove As from contaminated water, residual As and other constituents (e.g. Fe, nitrate) in the remediated water had a significant effect on freshwater organisms.]]> Sat 24 Mar 2018 07:24:13 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24101 Cucumis sativus L. (cucumber) and Triticum aestivum L. (wheat) and shoot end-points with a 4 week a pot study using cucumber only. Root elongation of cucumber was a substantially less sensitive indicator to As than data from the 4 weeks pot study. Effective concentrations (50%)(EC₅₀) from cucumber root elongation studies were overall 1.6 times higher than the 4 week shoot data. Cucumber was however considerably more sensitive to wheat. Given the large discrepancy in phytotoxicity end points for 7 soils, root elongation data for ecotoxicological assessment should be treated with some caution. Arsenic phytotoxicity was strongly related to the sorption constants of each of the seven soils in our study. Both root elongation and shoot data were related strongly to Freundlich partitioning constants (K_f) (L/kg). Wheat and cucumber root elongation had R² values 0.90 and 0.91 respectively, while cucumber shoot data was 0.79. The K_f values were related to soil pH and also EC₅₀ data and, thus, shows that As phytotoxicity in our study was primarily controlled by sorption reactions. The rate of As bioaccumulation to cucumber shoots depended heavily on the soil under consideration. Chlorophyll and carotenoid content of cucumber shoots increased with As content in 3 soils and decreased in other soils.]]> Sat 24 Mar 2018 07:11:45 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24051 Chlorella sp., were investigated using different phosphate levels. The results indicated that arsenate was highly toxic than arsenite to the alga, and the phosphate limitation in growth media greatly enhanced arsenate toxicity. The uptake of arsenate in algal cells was more than that of arsenite, and the predominant species in the growth media was arsenate after 8 days of exposure to arsenite or arsenate, indicating arsenite oxidation by this microalga. Arsenate reduction was also observed when the alga was incubated in a phosphate-limiting growth medium. Similar to the process of biotransformation, the alga accumulated more arsenic when it was exposed to arsenate and preferably more in a phosphate-limiting condition. Although phosphate significantly influences the biotransformation and bioaccumulation of arsenic, the oxidizing ability and higher accumulation capacity of this alga have great potential for its application in arsenic bioremediation.]]> Sat 24 Mar 2018 07:09:36 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39614 Mon 29 Jan 2024 18:47:47 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38254 Mon 29 Jan 2024 18:38:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36508 Rhodopseudomonas palustris C₁ and Rubrivivax benzoatilyticus C₃₁ to ameliorate As toxicity and to reduce As uptake in rice. Strain C₁ was superior to strain C₃₁ for siderophore production. The mixed culture (1: 1) was most effective in reducing the toxicity of As species [As(III) and/or As(V), each 30 mg/l] by yielding maximal germination index that related to α- and β-amylase activities in two Thai rice cultivars (HomNil: HN and PathumThani 1: PT). Arsenic toxicity to the seed germination followed the order: mixed As species > As(III) > As(V); and the toxicity was reduced in inoculated sets, particularly with a mixed culture. The mixed culture significantly enhanced rice growth under As stress in both rice cultivars as indicated by an increase in the production of chlorophyll a and b, and also supporting the non-enzymatic (carotenoids, lipid oxidation, and nitric oxide) and enzymatic (superoxide dismutase, ascorbate peroxidase, catalase, and glutathione reductase) activities. These were concomitant with productions of 5-aminolevulinic acid, indole-3-acetic acid, exopolymeric substances, and siderophores which significantly reduced As accumulation in treated rice. It can be concluded that the mixed culture has great potential to ameliorate rice from As toxicity by preventing As species entry into rice for enhancing rice growth and also for reducing As accumulation to produce safe rice from rice grown in contaminated paddy fields.]]> Mon 25 May 2020 12:29:48 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32809 Mon 23 Sep 2019 13:39:40 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47546 Mon 23 Jan 2023 12:29:58 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:18641 Mon 20 Jul 2015 16:52:24 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43435 P_app), with differences in ML retention and complexation amongst the chelants and the gut microbes. The decrease in ML permeability varied amongst the MLs. Chelating agents reduce intestinal absorption of MLs by forming complexes thereby making them less permeable. In the case of gut bacteria, the decrease in the intestinal permeability of MLs may be associated to a direct protection of the intestinal barrier against the MLs or indirect intestinal ML sequestration by the gut bacteria through adsorption on bacterial surface. Thus, both gut microbes and chelating agents can be used to decrease the intestinal permeability of MLs, thereby mitigating their toxicity.]]> Mon 19 Sep 2022 11:35:28 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51765 Cd > Pb > As(III)>As(V) for E. coli; and Hg > Cd > As(III)>Pb > As(V) for the two Lactobacillus sp. Arsenite (AsIII) showed higher toxicity than arsenate (AsV) to gut bacteria. While As is an anion, Cd, Pb and Hg are cations and hence their binding capacity to the bacterial cell wall varied based on the charge dependent functional groups. However, the toxic effects of PTEs for a bacteria are controlled by their speciation and bioavailability.]]> Mon 18 Sep 2023 14:23:29 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47379 Mon 16 Jan 2023 13:46:54 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39730 Mon 13 May 2024 13:29:27 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51570 Mon 11 Sep 2023 14:30:50 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39536 Mon 08 Aug 2022 11:27:21 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40433 Fri 29 Jul 2022 10:41:40 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45175 2+, Mn²⁺, Cu²⁺, H₂PO₄⁻ and SO₄²⁻) and organic acids (oxalic acid and citric acid). SEM and TEM analyses indicated that the MOF as a support efficiently prevent NZVI from aggregation for quick and effective removal of As(III). Through the non-linear least-squares (NLLS) adjustment, As(III) removal by MOF-NZVI could be well fitted by pseudo first and second order reaction kinetics, as well as the Freundlich isotherm. FTIR, XRD and XPS results verified that NZVI and iron oxyhydroxides (Fe₃O₄, γ-Fe₂O₃, γ-FeOOH and α-FeOOH) might be responsible for the effective removal of As(III) and its oxidized product As(V) with an adsorption capacity of 360.6 mg As per g NZVI through chemical oxidation and physical adsorption. This work indicates that MOF-NZVI with good reusability and high efficiency is promising for application in As(III)-polluted wastewater treatment.]]> Fri 28 Oct 2022 11:28:57 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41831 -1 and 400 mg kg^-1), F1 and F2 transformed to F4 and F5. Meanwhile, soil moisture had a significant influence on soil ALP activity. Soil ALP activity under 110% WHC was smaller than the activity of soil ALP under 35% WHC. The variation partitioning analysis (VPA) showed that soil moisture contributed 63.19% for this effect on soil ALP activity and was identified as the dominant factor. The value of ED 10 indicated that the As toxicity under 35% WHC was greater than that under 110% WHC. This could be due to that the excessive moisture content depressed soil ALP activity. Therefore, it is important to consider soil moisture content while assessing the As toxicity to soil ALP.]]> Fri 26 Aug 2022 11:21:16 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41080 Fri 22 Jul 2022 17:04:21 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30716 Fri 22 Apr 2022 10:25:35 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32802 Fri 22 Apr 2022 10:24:54 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42230 Fri 19 Aug 2022 11:35:34 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32983 max) and Michaelis constant (K_m) in unpolluted soils were 0.012-0.267 mM h^-1 and 1.34-3.79 mM respectively. The competitive inhibition constant (K_ic) was 0.17-0.70 mM, which was lower than K_m, suggesting higher enzyme affinity for As than for substrate. The ecological doses, ED₁₀ and ED₅₀ (concentration of As that results in 10% and 50% inhibition on enzyme parameter) for inhibition of catalytic efficiency (V_max/K_m) were lower than those for inhibition of enzyme activity at different substrate concentrations. This suggests that the integrated kinetic parameter, catalytic efficiency is substrate concentration independent and more sensitive to As than ALP activity. Thus, catalytic efficiency was proposed as a more reliable indicator than ALP activity for risk assessment of As pollution.]]> Fri 17 Aug 2018 15:44:20 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32987 m) and maximum reaction velocity (V_max) values of soil ACP ranged from 1.18 to 3.77 mM and 0.025–0.133 mM h⁻¹ in uncontaminated soils. The kinetic parameters of soil ACP in different soils changed differently with As contamination. The K_m remained unchanged and V_max decreased with increase of As concentration in most acid and neutral soils, indicating a noncompetitive inhibition mechanism. However, in alkaline soils, the K_m increased linearly and V_max decreased with increase of As concentration, indicating a mixed inhibition mechanism that include competitive and noncompetitive. The competitive inhibition constant (K_ic) and noncompetitive inhibition constant (K_iu) varied among soils and ranged from 0.38 to 3.65 mM and 0.84–7.43 mM respectively. The inhibitory effect of As on soil ACP was mostly affected by soil organic matter and cation exchange capacity. Those factors influenced the combination of As with enzyme, which resulted in a difference of As toxicity to soil ACP. Catalytic efficiency (V_max/K_m) of soil ACP was a sensitive kinetic parameter to assess the ecological risks of soil As contamination.]]> Fri 17 Aug 2018 15:43:55 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43401 Fri 16 Sep 2022 09:58:33 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54852 Fri 15 Mar 2024 17:15:42 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:54822 Fri 15 Mar 2024 08:36:58 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39082 n = 22) and shallow (n = 27) tubewells, were determined by atomic absorption spectrophotometer following APHA standard analytical methods. The examined parameters of water samples regarding the deep tubewell were found to have the following ranges: arsenic 2–145 µg/L; iron 80–6710 µg/L; manganese 8–80 µg/L; cadmium 1–8 µg/L; zinc 3–433 µg/L; and lead below the detection limit of 6 µg/L. In the shallow tubewell, the statistics were: arsenic 2–321 µg/L; iron 110–8670 µg/L; manganese 8–620 µg/L; cadmium 2–9 µg/L; zinc 3–81 µg/L; and lead below the detection limit of 6 µg/L. Drinking water quality of Narail Sadar does not satisfy the guidelines published by the World Health Organization or the government standards in Bangladesh. Deep tubewell water is comparatively less contaminated by arsenic and other trace metals than the shallow tubewell water, a finding based on the hazard quotient, carcinogenic risk and water quality index. Regular consumption of arsenic-contaminated water may accelerate chronic arsenic-related toxicity and subsequently endanger people’s health.]]> Fri 06 May 2022 15:00:38 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:36754 1 for arsenic in the tube wells water of seven Upazilas at Satkhira district. Lifetime drinking of arsenic-contaminated water may trigger cancer risk to the human health.]]> Fri 03 Jul 2020 09:54:41 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39995 Fri 01 Jul 2022 13:49:31 AEST ]]>