Health risk assessment of heavy metals (Cu, Zn, and Mn) in wild oat grown in soils amended with sediment dredged from the Joumine Dam in Bizerte, Tunisia

Abstract

The Joumine Dam located in northern Tunisia has lost more than 20% of its initial storage capacity due to sedimentation, meaning that sediment management is necessary. The sediments at the reservoir bottom act as a sink for nutrients and chemicals originating from the upper agricultural lands and take the form of suspended particles. We proposed that the dredged sediments could be used to amend arid to semiarid soils, as this would partially cover the financial burden of dredging works and reduce the volume of these deposits. However, to check the feasibility of using the sediments as a fertilizer, it was necessary to assess the potential health risks from contaminants in the sediments. Therefore, the present study aimed to evaluate the human health risk (i.e., the hazard quotient, HQ) from heavy metals consumed due to the ingestion of Bromus ramosus (wild oat) grown in soil amended with the Joumine Dam sediments. Plant growth was monitored in macrocosm (amendment rate of 1.17%) and microcosm (amendment rate ≤ 10%) bioassays to elucidate the metal concentrations in roots, stems, leaves, and seeds. Zn, Cu, and Mn concentrations were analyzed in the plants grown in the macrocosm experiments, while the follow-up was only performed for Zn in the plants grown in the microcosm experiments. The human exposure to soil pollutants (HESP) evaluation model was adopted to evaluate the health risk (HQ) to humans through direct and indirect oral exposure to heavy metals in wild oat. At the macrocosm scale, Cu was found to be the main source of risk (HQ = 1.86) to children. At the microcosm scale, utilization of the sediment reduced the mobility and bioavailability of copper in the soil, thus decreasing the potential health risk from this metal. Graphic abstract

Application of Different Indices for Soil Heavy Metal Pollution Risk Assessment Comparison and Uncertainty: A Case Study of a Copper Mine Tailing Site

“…The health risk index represents the possibility of human health damage in the presence of pollutants. A toxic or hazardous substance must reach a minimum dose (i.e., threshold) before it causes harm to the human body [39]. It can expressed using the hazard quotient (HQ), which is the ratio of the average daily human exposure dose (ADD, mg/kg/day) to the reference dose (R fD , mg/kg/day).…”

Ecological and Health Risk Assessments of Heavy Metals Contained in Sediments of Polish Dam Reservoirs

“…Sediments from reservoirs are used as fertilizers or agents to improve soil properties [50]. The accumulated heavy metals can be subject to sorption by plants [51]. Bottom sediments can be used as substrates for the growth of non-edible plants [52].…”

An Assessment of trace metals in selected Leafy vegetables in Lagos state

“…through the application of pesticides and herbicides and mineral fertilizer containing traces of heavy metals, usage of contaminated irrigation water and municipal waste for fertilization (Ben-Chabchoubi et al, 2020), emissions from farm inputs, direct waste disposal on farmland or use of dumpsite for farming (Anyanwu et al, 2004). Mining activities, emissions from industrial and transportation activities, sewage discharge,…”