Evaluation Of Holistic Approaches To Predicting The Concentrations Of Heavy Metals In Pots-Cultivated Durum Wheat(Triticum Durum L.)

Heavy metal pollution is a serious threat to food safety and public Health in the world.Because of this,a research was conducted on the evaluation of holistic approaches to predict the concentrations of heavy metals in pots-cultivated wheat.This study aims to determine accumulation of heavy metals?Cd,Cu,and Zn?in the soil and their translocation to the wheat crop grown in pots and to investigate the uptake of different heavy metals in different parts of durum Wheat and to assess the risk of these metals to plants and Human beings as they accumulates in the edible portion of the plant.The soil and wheat crop samples were prepared for heavy metal analysis using acid digestion and heavy metal concentrations were determined using ICP-OES method and AAS.ICP-MS was used to measured Heavy Metals concentration in soil extracted by DGT.The results showed that the accumulation of heavy metals in the polluted soil and parts of the wheat plant follows Zn>Cd>Cu.It was observed that Concentrations of Cd and Zn in grain were above the permissible limits of Cd and Zn in edible plants set by the FAO/WHO:Cd=1.95 and Zn=3.07.The concentration of heavy metals in the samples of wheat plants was also found to follow soil>root>shoot>grain.The uptake of Cd in the grains was found to be very high in T2?1.9780 mg/kg?,T5?1.9780 mg/kg?T6?1.9630 mg/kg?and T8?1.9667 mg/kg?;meanwhile,it was very low at T1?0.0486 mg/kg?,T3?0.0156 mg/kg?and T4?0.0153 mg/kg?and T70.0921 mg/kg).Whereas Cu uptake was noticed to be high in T3?0.2711mg/kg?,T5?0.2342 mg/kg?,T7?0.2307 mg/kg?and T8?0.2199 mg/kg?.Also,it was very low in T1?0.0986 mg/kg?,T2?0.0213 mg/kg?,T4?0.0404 mg/kg?and T6?0.0240 mg/kg?.For the uptake of Zn,T4?3.0721 mg/kg?and T7?2.9802 mg/kg?recorded the highest values of Zn uptake.DGT measure the highest concentration of Cd?16.476?g/l?,Zn?50.0854?g/l?and Cu?41.2257?g/l?concentrations in the soil.In wheat plant,the grain is the edible portion that is consumed directly by human.Therefore,the level of heavy metals in grain endangers human health.For that reason,the transferred of metal concentrations in wheat grains should be investigated along with metal concentrations in the roots and shoots and soil,to determine the transport relationship of different HMs within the whole Wheat plant.Among the Plant part study,the roots have the strongest accumulation capacity for all the HMs,which are the parts in direct contact with soil,also,the roots is the main pathway of heavy metal uptake in wheat plant.As a result,the concentration heavy metal is usually higher in the roots than in the other plant parts,but on the contrary in this study.In the midst of the three?3?HMs study,Cd and Zn are the most accumulated heavy metal in the wheat plant parts?root and grain?,and Cu is the least accumulated heavy metal in the plant grains.A number of studies have shown that heavy metals content in the soil may raise the level of Cd in plants.However,a close connection between the concentration of heavy metals in plants and the soil is difficult to be found,as the metal bioavailability of the soil depends on several factors,like plant growth and distribution of metal in different parts of the plants.In different wheat plant parts,there are some correlations between the different HMs,but no consistent patterns are found,which Shows that the enrichment process of different heavy metals in wheat is very complex.Of all the extraction procedures used in this study,DGT technique extracted more Heavy Metals compare to the soil solution,HAc and HNO₃.It was established therefore in this study that DGT showed accurate concentration of plant available Cu than HNO₃but not of plant available Zn and Cd.Copper plant concentration showed significant correlation to extracted Cu by all the methods?DGT,HNO₃,CaCl₂,HAc and Soil Solution?but DGT had the strongest significant correlation at?R²=0.875^***,p?0.001?.Copper and Cadmium concentration measured by the DGT technique showed significant correlation between the extracted Cu and Cd by Soil solution,HNO₃ and CaCl₂.Zinc measured by DGT did not show significant correlations to the Zn plant concentration or to extracted Zn concentrations by HNO₃and CaCl₂.It was established in this research that DGT was the most accurate method for predicting plant available Cu but not for Cd or Zn.DGT being a robust extraction procedure as confirmed in this study,further research is needed to be carry out before considering the DGT technique as one of the conventional and reliable soil testing methods in China.