Geochemical signatures and human health risk evaluation of rare earth elements in soils and plants of the northeastern Qinghai-Tibet Plateau,China

Information on rare earth elements(REEs)in soils and plants of the Qinghai-Tibet Plateau is very limited.Therefore,in this study,we performed field sampling to explore the geochemical signatures and human health risk of REEs in soils and plants of the northeastern Qinghai-Tibet Plateau,China.A total of 127 soil samples and 127 plant samples were collected from the northeastern Qinghai-Tibet Plateau to acquire the geochemical signatures and related human health risks of REEs.The mean total concentrations of REEs in soils and plants of the study area reached 178.55 and 10.06 mg/kg,respectively.The light REEs in soils and plants accounted for 76%and 77%of the total REEs,respectively.REEs showed significantly homogenous distribution in soils but inhomogeneous distribution in plants of the study area.Characteristic parameters indicated that light REEs were enriched and fractionated significantly,while heavy REEs were moderately fractionated in soils and plants.REEs in soils and plants showed significantly negative Europium anomaly.Cerium showed slightly positive anomaly in plants and slight anomaly in soils.The normalized distribution patterns of REEs were generally similar in the analyzed soils and the corresponding plants of the study area.The average bio-concentration factor of REEs ranged from 0.0478(Scandium)to 0.0604(Europium),confirming a small accumulation of REEs by plants.Health risks caused by REEs in soils and plants were negligible,while risks for adults were lower than those for children.This study provides important information on REEs in soils and plants of the northeastern Qinghai-Tibet Plateau.

Assessment of Metal Accumulation in the Vegetables and Associated Health Risk in the Upper-Most Ganga-Yamuna Doab Region, India

The present study indicates the status of metal contamination in the vegetables/crops grown in the upper most Ganga-Yamuna doab region of India and associated health risk. Commonly grown vegetables and crops were sampled and analyzed for the metal contamination. Maximum concentration (mg/kg) of Cd and Cr, was observed in Radish (7.6) and Cabbage (56.24) respectively, whereas maximum concentration of Pb, Ni and Zn was observed in the edible parts of Mustard plant (95.4, 58.6, 756.43 respectively). Bio-concentration factor (BCF) value indicated the transfer level of metal from soil to crop;indicated high transfer value of Cd in Radish followed by cabbage and spinach. Considerably high BCF value was observed in the Mustard (8.13), Cabbage (4.18) and radish (3.07) for Zn contamination. Estimated daily intake (EDI) and Hazard quotient (HQ) or Non-carcinogenic health risk was calculated using the USEPA method. The result revealed that the metal intake and associated health risk were considerably high in the children population in comparison to the adult population.

Health Risks of Trace Metals in Wastewater-Fed Fishes:A Case Study

In this study,the usage wastewater from secondary treatment in feeding fishes of Carassius gibelio species and suitability of the fishes for human food were evaluated.The metals(Ag,Al,As and B)in treated effluent and skeleton,skin,eyes and brain tissues of fishes were examined seasonally.It was found that treated effluent was not suitable for irrigation and aquaculture in terms of Al according to the Turkish standard values.According to annual averages the size order of Ag and B concentrations were skeleton>skin>eyes>brain and skeleton>skin>brain>eye respectively.Also,skin>brain>eyes>skeleton was for As and Al.TF(Transfer Factor)values of all metals examined were determined as>1 in the four tissues and the metals caused bioaccumulation because of treated effluent.Concentrations in muscles were found 7 to 6227 times higher than in water.The size order of TF and BCF(Bio-concentration Factor)values in skin and eye tissue were the same and it was Ag>Al>As>B.It was Ag>Al>As>B in skeleton,Al>As>Ag>B in brain.HQ(Hazard Quotient)of Al in all tissues had carcinogenic risk level.

A comparison on the phytoremediation ability of triazophos by different macrophytes

The strategy of choosing suitable plants should receive great performance in phytoremediation of surface water polluted by triazophos （O,O-diethyl-O-（1-phenyl- 1,2,4-triazol-3-base） sulfur phosphate, TAP）, which is an organophosphorus pesticide widespread applied for agriculture in China and moderately toxic to higher animal and fish. The tolerance, uptake, transformation and removal of TAP by twelve species of macrophytes were examined in a hydroponic system and a comprehensive score （CS） of five parameters （relative growth rate （RGR）, biomass, root/shoot ratio, removal capacity （RC）, and bio-concentration factor （BCF）） by factor analysis was employed to screen the potential macrophyte species for TAP phytoremediation. The results showed that Thalia dealbata, Cyperus alternifolius, Canna indica and Acorus calamus had higher RGR values, indicating these four species having stronger growth capacity under TAP stress. The higher RC loading in Iris pseudacorus and Cyperus rotundus were 42.11 and 24.63μg/（g fw.day）, respectively. The highest values of BCF occurred in A. calamus （1.17）, and TF occurred in Eichhornia crassipes （2.14）. Biomass and root/shoot ratio of plant showed significant positive correlation with first-order kinetic constant of TAP removal in the hydroponic system, indicating that plant biomass and root system play important roles in remediation of TAP. Five plant species including C. alternifolius, A. calamus, T. dealbata, C. indica and Typha orientalis, which owned higher CS, would be potential species for TAP phytoremediation of contaminated water bodies.