There are a number of factors that contribute to heavy metal contamination in agricultural soils including deficient management of solid waste, waste water discharge, irrigation with contaminated water, and use of fer...There are a number of factors that contribute to heavy metal contamination in agricultural soils including deficient management of solid waste, waste water discharge, irrigation with contaminated water, and use of fertilizers and pesticides. The aim of this study is to estimate the sources and the levels of metals in soils of the ULB （Upper Litani Basin） that receive all mentioned factors. Soil samples were collected during the dry season from 24 sites along the Litani River flow, and 12 sites irrigated by Canal 900 withdrawn from the Qaraoun Dam along river. Metals in soils were analyzed using EDXRF （energy dispersive X-ray fluorescence） technique. Data revealed the following average levels of some heavy metals in soils with high percentage of samples exceeding the international guidelines： Mn （593 mg/kg）--67%, Ni （98 mg/kg）--96%, Cr （143 mg/kg）--92%, Hg （3.6 mg/kg）--38%, Cd （2.8 mg/kg）---25% and As （17.6 mg/kg）-84%. In canal soils： Mn （683 mg/kg）-86%, Ni （156 mg/kg）-100%, Cr （203 mg/kg） -100%, Hg （2.3 mg/kg）-25%, Cd （3.3 mg/kg）-25% and As （19.5 mg/kg）-92%. The prime source of toxic metals was due to the agricultural runoffs, beside sewage and domestic waste water discharge. Thus, the prominent findings of high levels of toxic metals （Cr, Cd, Hg and As） in soils and consequent probability in plants might induce a major health threat to consumers,展开更多
Lebanese marine water is exposed to multi-point source contaminants. Risk assessment associated with deteriorative water quality profile is not only affected by the disposed quantities of specific contaminant, but als...Lebanese marine water is exposed to multi-point source contaminants. Risk assessment associated with deteriorative water quality profile is not only affected by the disposed quantities of specific contaminant, but also its chemical speciated forms. The objective of this study is to quantify the Lebanese chemical marine water profile. Sea water samples were collected based on GIS map. The chemical water quality was assessed by measuring the macro water parameters and potential existing metals. The microbiological profile of water was evaluated by fecal coliform. Results showed contamination by fecal coliform and high levels of toxic metals. However, the actual projected impact of the detected metals on human health were assessed using geochemical models ＂FREEQCE＂ and ＂Mineq＋＂ that predict the metal species forms, mainly, the free aqua-metal ion, most toxic form. Thus, these results necessitate the proposal of integrated intervention plans for the protection of this marine source and consistent with international treaties.展开更多
文摘There are a number of factors that contribute to heavy metal contamination in agricultural soils including deficient management of solid waste, waste water discharge, irrigation with contaminated water, and use of fertilizers and pesticides. The aim of this study is to estimate the sources and the levels of metals in soils of the ULB （Upper Litani Basin） that receive all mentioned factors. Soil samples were collected during the dry season from 24 sites along the Litani River flow, and 12 sites irrigated by Canal 900 withdrawn from the Qaraoun Dam along river. Metals in soils were analyzed using EDXRF （energy dispersive X-ray fluorescence） technique. Data revealed the following average levels of some heavy metals in soils with high percentage of samples exceeding the international guidelines： Mn （593 mg/kg）--67%, Ni （98 mg/kg）--96%, Cr （143 mg/kg）--92%, Hg （3.6 mg/kg）--38%, Cd （2.8 mg/kg）---25% and As （17.6 mg/kg）-84%. In canal soils： Mn （683 mg/kg）-86%, Ni （156 mg/kg）-100%, Cr （203 mg/kg） -100%, Hg （2.3 mg/kg）-25%, Cd （3.3 mg/kg）-25% and As （19.5 mg/kg）-92%. The prime source of toxic metals was due to the agricultural runoffs, beside sewage and domestic waste water discharge. Thus, the prominent findings of high levels of toxic metals （Cr, Cd, Hg and As） in soils and consequent probability in plants might induce a major health threat to consumers,
文摘Lebanese marine water is exposed to multi-point source contaminants. Risk assessment associated with deteriorative water quality profile is not only affected by the disposed quantities of specific contaminant, but also its chemical speciated forms. The objective of this study is to quantify the Lebanese chemical marine water profile. Sea water samples were collected based on GIS map. The chemical water quality was assessed by measuring the macro water parameters and potential existing metals. The microbiological profile of water was evaluated by fecal coliform. Results showed contamination by fecal coliform and high levels of toxic metals. However, the actual projected impact of the detected metals on human health were assessed using geochemical models ＂FREEQCE＂ and ＂Mineq＋＂ that predict the metal species forms, mainly, the free aqua-metal ion, most toxic form. Thus, these results necessitate the proposal of integrated intervention plans for the protection of this marine source and consistent with international treaties.
