Molla Rahman Shaibur

This study investigated the chemical properties and concentrations of major pollutants, including toxic elements, across four zones of Erbil City: city center, industrial, residential, and suburban areas, with samples collected from five sub‐sites in each zone. The pH, electrical conductivity (EC), total dissolved solids (TDS), nitrate (NO ₃ ), sulfate (SO ₄ ), ammonium (NH ₄ ) and major toxic elements including chromium (Cr), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were analyzed. In the study area, the pH values ranged from 5.1 to 6.7 with industrial sites revealing slightly acidic conditions (5.1–5.3). Industrial zones revealed elevated EC (> 690 μS/cm) and TDS (> 500 mg/L), alongside high NO ₃ concentrations (7.5 to 8.1 mg/L). Heavy metal analysis revealed that heavy metal concentrations were highest in industrial areas, with Pb reaching 48.0 μg/L, Cd 2.1 μg/L, Cr 4.5 μg/L, and As 3.60 μg/L, which were higher than WHO guidelines. While in residential areas, NH ₄ levels were (> 0.32 ± 0.02 mg/L). Sulfate concentrations varied between 0.50 and 2.0 mg/L, with industrial sites showing the highest values, and concentrations increased. The results demonstrated that the city center and residential areas showed moderate contamination, while suburban areas demonstrated the lowest pollutant concentrations and revealed minimal anthropogenic influence. The study demonstrated that around 70% of samples posed moderate to high noncarcinogenic risks for children in the studied sites.

This study evaluated heavy metal (HM) contamination in sediments from the Malbasag River in the Ormoc City port, Leyte, Philippines. A total of thirty sediment samples were collected randomly from ten locations along the river using an Ekman grab sampler. Atomic absorption spectrophotometry revealed HM concentrations in the order of Mn > Zn > Cu > Ni > Pb > Cd. All HMs exceeded their sediment quality guideline (SQG) thresholds except for Mn. Contamination was assessed using indices such as the contamination factor (CF), pollution load index (PLI), geo-accumulation index (I_geo), and enrichment factor (EF). The CF values indicated “moderate to considerable” contamination for Zn, Ni, and Cd, while Cu and Pb showed “very high” contamination levels. The PLI results indicated severe sediment degradation in 20% of samples. The I_geo analysis classified 60% of the samples as “heavily to extremely polluted” for Cd, Cu, and Pb. EF analysis suggested that anthropogenic sources contributed to elevated HM levels, including port activities and agricultural runoff. Ecological risk index (RI) analysis revealed moderate risk in 40% and considerable risk in 20% of sampling locations. Multivariate analyses suggested significant anthropogenic contributions to HM contamination, highlighting the need for further studies to assess the ecological impacts.

Groundwater (GW) quality is a critical factor for its use in drinking and irrigation purpose and has become a significant concern in the southwestern region of Bangladesh. This study aims to conduct an in‐depth hydrogeochemical characterization and assess the suitability of GW for both drinking and irrigation purposes. Water samples were collected randomly from 42 tube wells and analyzed for 10 water quality parameters, along with 3 metallic pollutants, to evaluate their hydrogeochemical properties. The results of various analyses indicated that the relative concentrations of major ions follow the order: Ca ²⁺ > Na ⁺ > Mg ²⁺ > K ⁺ and HCO ₃ ⁻ > Cl ⁻ > SO ₄ ²⁻ . Principal component analysis suggests that the hydrogeochemistry of the GW in the study area is primarily influenced by both geogenic processes (such as weathering and leaching of host rocks) and anthropogenic activities (including the use of agrochemicals, sewage sludge, and municipal solid waste disposal). The water quality index indicated that approximately 38% of the water sources were classified as good, 28% as poor, 10% as very poor, and the remaining 24% were unsuitable for drinking purposes. The Piper diagram reveals that the predominant GW types were Ca ²⁺ ‐HCO ₃ ⁻ (80%) and Ca ²⁺ ‐Na ⁺ ‐HCO ₃ ⁻ (20%). A notable finding from this analysis was that basalt weathering—via surface runoff into aquifers—was the dominant process contributing to GW mineralization, along with silicate weathering, carbonate weathering, and ion exchange. Additionally, agricultural practices have a significant impact on the mineralization process. The hazard index indicates that approximately 40.5% of adults and 90.48% of children were exposed to high noncarcinogenic risks due to the use of contaminated water. Alarmingly, both adults and children were facing significant carcinogenic risks from the same exposure. According to the irrigation water quality index, parameters such as total hardness, Kelly’s ratio, and sodium adsorption ratio indicate that approximately 50% of the water sources were unsuitable for irrigation. Therefore, based on these findings, Magura Sadar Upazila requires targeted spatial management to ensure a safe drinking water supply and promote sustainable agricultural practices.