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To assess the human impact on the water of Dayat Roumi Lake and to develop effective management strategies to protect and restore this vital ecosystem in the region, seasonal sampling was carried out at six stations distributed around the lake. During these sampling campaigns, 24 parameters were measured, including 20 trace elements. Results showed that measured levels of trace elements increased in the following order: Cd < Be < Tl < Co < Sb < Mo < Cu < Zn < Ni < V < Rb < Mn < As < Cr < Pb < Li < Ba < Se < Pd < Sr in the lake water and that these recorded values were lower than those recommended by the Moroccan standard and the World Health Organization, except for Pb and Se. Correlation analysis revealed two principal water-contamination sources: natural geological origins and anthropogenic inputs. In addition, the Water Quality Index WQI showed that the lake’s water quality is poor, and its use can be dangerous for human and animal health. Health risk assessment associated with prolonged exposure to trace elements in lake water revealed that the Hazard quotient HQ and Hazard index HI of certain elements, such as Tl, Sb, V, As, Cr, Pb, Li, and Se, are higher than 1 in adult and children, indicating a significant risk for people living near the lake. Children are particularly vulnerable, with higher levels of HQ and HI, and selenium poses a substantial risk to their health through ingestion and skin absorption. In both adults and children, the total risk of cancer due to metals is classified as follows: CI (Cr) > CI (Ni) > CI (As) > CI (Pb) > CI (Cd). The Cr presents the highest carcinogenic risk—by ingestion or dermal route—in both groups. The total risk for these five metals exceeds 1 × 10⁻⁴, indicating a danger for residents who drink or swim in the lake. Full article

As in many countries worldwide, deterioration of quality of water in Morocco’s natural reserves continues, such that an inventory of qualities of these reserves has become necessary. Based on statistical analyses of the data collected by measuring nineteen physicochemical variables, and applying an index, the comprehensive pollution index, to those data, the quality of the waters of Lake Dayat Roumi, Morocco, were assessed. Waters of the lake are currently characterized by a salinity of 921.7 mg Cl⁻/L and 124.2 mg sulfates/L. The concentration of chloride exceeds the value indicated in the standard norms. This can affect the composition of the sediment, overlying water, and specific composition of biota in the lake. Status and trends of values of other parameters also indicate deterioration of water quality in this lake. Multivariate statistical analysis made it possible to differentiate four clusters of samples according to their physicochemical characteristics. These groups are due to inputs from three sources of materials: leaching of rocks from the watershed and plantations, discharge of domestic wastewater and runoff water. Samples taken from deeper parts of the lake indicate a depression of concentrations of dissolved oxygen during the hot season. The analysis results demonstrate the heterogeneous degradation of the water quality in the peripheral areas and deep parts of the lake, favored by the leaching of soils by rainwater, which, when sufficiently severe, can cause repeated mortalities of fishes. This situation requires regular water quality monitoring to develop a management plan for restoration of water quality in the lake to preserve valued ecological services. Full article