Spatial Assessment of Airborne Atmospheric Heavy Metals Across Key Monitoring Stations in Baghdad

 Detection of Air Pollution with Lead, Cadmium, and Zinc in Selected Industrial Areas of Baghdad

The objectives of this study are to investigate the concentrations of heavy metals in two selected industrial areas. Airborne heavy metal pollution represents a persistent environmental and public health problem in rapidly urbanizing cities. This research assesses the seasonal distribution of lead (Pb), cadmium (Cd), and zinc (Zn) associated with airborne particulate matter in two selected industrial areas including Al Bayaa on the Karkh side and Al Shurta Tunnel on the Rusafa side of Baghdad and a rural control site. Samples of air were collected during four seasons autumn, winter, spring, and summer and then analyzed using atomic absorption spectrometry AAS. The results revealed pronounced seasonal differences, Lead concentrations varied across the four seasons, with the highest concentration recorded in the summer at the Al Shurta Tunnel, reaching 5.8 µg/m³, while the lowest concentration was recorded in the same area during the winter at 0.0185 µg/m³. Cadmium concentrations were recorded at their lowest value of 0.0294 µg/m³ in winter in the police tunnel and at their highest concentration of 4 µg/m³ in the Al Bayyaa area in spring. As for zinc, its concentrations ranged between 2.257 µg/m³ and 43.8 µg/m³ in the winter and spring, respectively, in the police tunnel area. In general Cd levels remained low but exhibited episodic increases, particularly in Al Bayaa. Although most measured concentrations were below commonly cited health-based guideline values, the consistent detection of heavy metals highlights their persistence in Baghdad industrial atmosphere. These findings provide baseline data for Baghdad and emphasize the necessity for continuous monitoring and strengthened air quality management strategies.

Spatiotemporal Assessment of Heavy Metal Accumulation in Urban Soils: A Four-Year Monitoring Study in Thessaloniki, Greece (2021–2024)

This study investigates the spatiotemporal distribution of heavy metals in urban soils of Thessaloniki, Greece, over a four-year monitoring period (2021–2024). A total of 664 soil samples were collected across diverse land-use types during both wet (winter) and dry (summer) seasons. Soil physicochemical properties were analyzed alongside cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) concentrations. The results reveal distinct, element-specific accumulation dynamics driven by continuous anthropogenic inputs. Statistical and geospatial analyses confirm that Cd exhibits a highly significant, progressive accumulation and spatial expansion toward residential areas. In contrast, Cu and Pb demonstrate a gradual, chronic enrichment, eventually reaching a saturation point where winter precipitation is insufficient to offset summer deposition. Zn presents as a severe but temporally stable contamination burden, anchored to the northwestern industrial–port sector. Furthermore, the alkaline properties of the local urban soils were found to act as an effective sink, immobilizing contaminants and preventing downward leaching. The Geo-accumulation Index (Igeo) confirms a progressive decline in soil quality driven primarily by cadmium, while the other trace elements exhibit persistent, stable profiles. Overall, this study establishes a vital geochemical baseline of total heavy metal loading in Mediterranean urban soils, emphasizing the need for targeted emission controls and future mobile-fraction assessments to guide sustainable urban management.

Human health risk assessment of heavy metal pollution in airborne dust from Zakho City, Iraq

Multi-Compartment Pollution Assessment of Soil Metals and Air Pollutants in Lebanon’s Bekaa Valley: Integrating Geochemistry, Remote Sensing, and Multi-Scale Spatial Analysis

This study presents the first integrated multi-compartment assessment linking soil heavy- metal contamination and satellite-derived tropospheric air pollution in Lebanon’s Bekaa Valley. Six metals (Cd, Cr, Cu, Ni, Pb, Zn) were measured in 295 agricultural topsoils using DTPA extraction—which targets the labile, bioavailable pool most relevant to food-chain transfer in calcareous soils—and were compared with Sentinel-5P TROPOMI vertical columns of SO2, NO2 and HCHO extracted at point, 1000 m and 5000 m scales. Chromium was the dominant element, and composite pollution indices indicated overall good but transitional soil quality, with a majority of sites at warning level. Principal component analysis, spatial autocorrelation and land-use analysis converged on three plausible source groupings—predominantly geogenic (Cr, Ni), localized anthropogenic (Cd, Pb) and agricultural (Cu)—although, in the absence of isotopic or other direct source tracing, these assignments remain indicative rather than confirmed. Soil metals and atmospheric columns were largely uncorrelated (|r| < 0.3 for 17 of 18 pairs); this decoupling is consistent with the contrasting temporal integration and spatial support of the two compartments rather than with a single shared pathway. Multi-scale analysis supported a parsimonious dual-scale (point + 5000 m) sampling framework. The study offers a transferable assessment framework for other Mediterranean regions and underscores the need for locally calibrated, total-metal soil background values. Because these indices and threshold comparisons are computed from DTPA-extractable concentrations, they serve here as one-directional, bioavailability-based screening tools rather than regulatory determinations: an exceedance conservatively flags a site for confirmatory total-metal analysis, whereas a non-exceedance does not establish compliance.

Spatial patterns and ecological significance of heavy metals in water and sediments of the Drini–Buna river system

The Drini River Basin represents the largest river system in Albania and plays a key role in supporting freshwater resources, biodiversity, hydropower production, and human activities. This study evaluated the distribution, contamination status, and ecological risk of trace metals in water and surface sediments collected from eleven stations covering the basin of the river. Concentrations of metals were determined and interpreted using contamination indices, including the geoaccumulation index (Igeo), Nemerow pollution index (NPI), and potential ecological risk index (PERI). Trace metal concentrations exhibited significant spatial variability, with the highest enrichment observed for Ni, Cr, and Co. Geoaccumulation index results classified these metals as moderately to heavily con - taminated at several stations, particularly in the upper basin and the Zalli River. In contrast, Cu, Mn, Fe, Al, Pb, Cd, and Hg generally remained within the uncontaminated or slightly contaminated categories. The NPI values for water were below 1 at all stations, indicating no significant metal pollution in the water column. PERI values ranged from low to moderate ecological risk, with no station exceeding the threshold for considerable ecological risk. The highest ecological risk was observed at the Zalli stream station, while the Bushtrica River exhibited the lowest contamination and risk levels. The spatial distribution of metals suggests that sediment contamination is controlled predominantly by geogenic factors associated with ultramafic and ophiolitic formations characteristic of northeastern Albania, although localized contributions from historical mining activities cannot be ruled out. Results indicated good water quality with respect to trace metals and low to moderate ecological risk in sediments, providing an important baseline for future monitoring and management of the Drini River Basin.

Heavy Metal Contamination and Ecological Risk Assessment in the Bhairab–Rupsha River Basin: An Integrated Approach Using Pollution Indices, Spatial Mapping, and Multivariate Analysis

Heavy metal contamination in tidal river systems is an increasing environmental concern in rapidly urbanizing regions of South Asia. This study presents an integrated assessment of heavy metal pollution and ecological risk in the Bhairab–Rupsha River basin, Bangladesh. Concentrations of six priority metals—chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb)—were determined in water and surface sediments collected during the pre‐ and post‐monsoon seasons using inductively coupled plasma–mass spectrometry (ICP–MS). Data quality was ensured through strict QA/QC procedures. Pollution and ecological risks were evaluated using the heavy metal pollution index (HPI), heavy metal evaluation index (HEI), water–sediment concentration factor ( K d ), contamination factor ( C f ), degree of contamination ( C d ), pollution load index (PLI), geo‐accumulation index ( I geo ), ecological risk factor ( E r ), potential ecological risk index (PER), spatial mapping, and principal component analysis (PCA). Water samples showed the concentration order as follows: Cu > Cr > Ni > Pb > Zn > Cd, with Cr, Cd, and Pb exceeding the Bangladesh Environmental Conservation Rules and the relevant United States Environmental Protection Agency (USEPA) and CCME aquatic life guidelines. HPI values exceeded the critical limit (>100) at all stations, indicating severe water quality deterioration, particularly downstream. In contrast, sediment metal concentrations remained below guideline thresholds, with C f  < 1, C d  < 8, PLI < 1, I geo  < 0, and PER indicating low ecological risk. Spatial analysis revealed increasing downstream enrichment associated with industrial discharges, municipal wastewater, and port activities. PCA explained 98.8% of the total variance, suggesting a dominant anthropogenic source of contamination.