https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29511 Cucumis sativa L. (cucumber). The parameter log K_f was predicted with soil pH_ca, logCEC and log OC. Transfer of soil pore-water Cd²⁺ to shoots was described with a power function (R² = 0.73). The dataset was validated with 13 long-term contaminated soils (plus 2 control soils) ranging in Cd concentration from 0.2 to 300 mg kg⁻¹. The series of equations predicting Cd_shoot from pore-water Cd²⁺ were able to predict the measured data in the independent dataset (root mean square error = 2.2). The good relationship indicated that Cd uptake to cucumber shoots could be predicted with Cd_pore and Cd²⁺ without other pore-water parameters such as pH or Ca²⁺. The approach may be adapted to a range of plant species.]]> Wed 23 Feb 2022 16:06:46 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18762 Wed 11 Apr 2018 14:54:37 AEST ]]> https://nova.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://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29927 Cucumis sativa L. (cucumber) focusing primarily on pore-water Pb data from 10 different soils after 12 weeks ageing. Phytotoxicity expressed in terms of Pb²⁺ was observed to occur in the nanomolar range in neutral to alkaline soils (EC50 values 90 to 853 nM) and micromolar levels for acidic soils (EC50 values 7.35 to 9.66 μM). Internal Pb concentrations relating to toxicity (PT50) in roots and shoots also decreased with increasing pore-water pH (R² = 0.52 to 0.53). From a series of dose-response studies, we developed transfer functions predicting Pb uptake in C. sativa and we validated these functions with long-term Pb contaminated soils. The significant independent parameters were pore-water Pb²⁺ and dissolved Pb plus dissolved organic carbon (DOC). The observed RMSE for the Pb-DOC model and Pb²⁺ were 2.6 and 8.8, respectively. The Pb-DOC model tended to under-predict Pb, whilst Pb²⁺ tended to over-predict accumulation despite reasonable RMSE values. Further validation is needed in soils with higher pore-water Pb solubility.]]> Sat 24 Mar 2018 07:30:55 AEDT ]]> https://nova.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://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52999 Vigna radiata) in two contrast soil types (Dermosol and Tenosol). The soil types with added Zn and Cd exerted a significant effect on translocation and accumulation of metals in different tissues. The accumulation of Zn and Cd was higher for Tenosol than that for Dermosol. At control, the concentration of Cd followed a pattern, e.g., root > stem > petiole > pod > leaflet > grain for both soils. A basal Zn supply (5 mg kg^-1) increased the grain Zn concentration to a significant amount (up to 67%). It also reduced Cd accumulation in tissues, including grains (up to 34%). No non-carcinogenic effect was observed for either the children or the adults as the EDI and PTDI values were below the safety limit; however, the ILCR values exceeded the safety limit, indicating the possibility of some carcinogenic effects. Added Zn helped to reduce the carcinogenic and non-carcinogenic health risks on humans.]]> Fri 03 Nov 2023 16:05:28 AEDT ]]>