Ecological and Health Risks Assessment of Potentially Toxic Metals and Metalloids Contaminants: A Case Study of Agricultural Soils in Qatar

Abstract

In recent years, Qatar has witnessed exponential growth in the human population, urbanization, and increased anthropogenic activities, including agriculture. Potentially toxic environmental contaminants, including metals and metalloids, are commonly found in emerging economies. At high concentrations, elements such as As, Cr, and Ni can be hazardous and may lead to various health problems in humans, including cancer. The current study measured As, Cd, Cr, Cu, Ni, Pb, V, and Zn concentrations in agricultural soils. Pollution levels and potential negative impacts on human and environmental health were determined using the United States Environmental Protection Agency (USEPA) standard methodologies. According to the study’s findings, the studied element concentrations descended in the following order: Zn > Cr > V > Ni > As > Cu > Pb > Cd. Of these, As (27.6 mg/kg), Cr (85.7 mg/kg), Ni (61.9 mg/kg), and Zn (92.3 mg/kg) concentrations were higher than average world background levels. Each of these elements also had an enrichment factor (EF > 1), indicating their anthropogenic origin. The combined pollution load index (PLI > 1) and geo-accumulation index (Igeo) range values of −0.2–2.5 further indicated that the soil was up to 58% polluted. However, the ecological risk factor (Er ≤ 40.6) and potential ecological risk index (PERI = 79.6) suggested low ecological risk. A human health risk evaluation showed that only As, with a hazard index (HI) of 1.3, posed a noncarcinogenic risk to infants. Additionally, As, Cr, and Ni, with total carcinogenic risk (TCR) values of 1.18 × 10−4 and 2.06 × 10−4 for adults and children, respectively, proved carcinogenic to both age groups. The elements’ carcinogenic risk (CR) potential descended in the following order: Ni > As > Cr. Additionally, for both adults and children, oral ingestion is the most likely exposure pathway. Our findings support the need for closer monitoring of potentially toxic metals and metalloids levels in cultivated soils and farm produce in Qatar. Reducing the elements’ bioavailability in soil and developing innovative remediation technologies is needed to limit potential risks to human health. Further studies on As, Cr, and Ni gastrointestinal bioaccessibilities are needed to fully understand the effects after long-term exposure and the cancer-causing potential of these elements over a lifetime.

The Carcinogenic and Non-Carcinogenic Health Risks of Metal(oid)s Bioaccumulation in Leafy Vegetables: A Consumption Advisory

“…Previously, we reported high levels (in the cultivated soil) of some of the elements studied here (Alsafran et al, 2021). The objectives of the current study were to determine the levels of As, Cd, Cr, Cu, Ni, Pb, and V in three major leafy vegetables (rocca, coriander, and parsley) grown in the same cultivated soil and evaluate the human health risks among the adult (male and female) population in Qatar.…”

“…Another notable characteristic is that the peninsula is covered with pebbles and sand that have detached from outcropped limestone (Peng et al, 2016;Al-Sulaiti et al, 2017). While there is insufficient knowledge about lithological events in Qatar, the country's exterior predominately rests on layers of clay and limestone (Alsafran et al, 2021;Fourniadis, 2010). Earlier studies on metal(oid) remediation in Qatar's natural soil have found that the concentrations of some elements were below detection limit (Usman et al, 2019;Al-Thani and Yasseen, 2020).…”

“…Leafy vegetables could absorb higher concentrations than typical plants due to their high growth rates (Khan et al, 2013). The elements accumulation in vegetable samples may be due to chemical fertilizer usage or the discharge of untreated solid and/or fluid waste from factories in the surrounding areas (Alsafran et al, 2021). Toxic levels of these metal(oid)s in the vegetables studied may harm the health of the residents who stay nearby.…”

“…Previous reports documented the occurrence of potential toxic metal(oid)s investigated in the present study in both cultivated (Peng et al, 2016) and noncultivated soil (Usman et al, 2019;Usman et al, 2020b) in Qatar. Additionally, more recently, Alsafran et al (2021) found that As, Cr, and Ni concentrations in agricultural soil were higher than the USEPA recommended level and pose significant risks to human health, particularly children.…”

Understanding the Phytoremediation Mechanisms of Potentially Toxic Elements: A Proteomic Overview of Recent Advances

“…The continued accumulation of potentially toxic elements (PTEs), including cadmium (Cd), lead (Pb), chromium (Cr) and arsenic (As), copper (Cu), mercury (Hg), nickel (Ni), and selenium (Se) in the environment poses a significant danger to human health and undermines global environmental sustainability efforts ( Habiba et al, 2019 ; Rizvi et al, 2019 , 2020 ; Alsafran et al, 2021 ). Anthropogenic activities due to rapid industrialization, especially from oil and gas producing industries, infrastructural development, mining, foundries, smelters, coal-burning power plants, and agricultural activities, are significant contributors that enhance the elements of hazardous pollutants in the soil ( Al-Thani and Yasseen, 2020 ; Yan et al, 2020 ; Usman et al, 2020b ).…”