Spatial distribution and health risk implications of elemental hazard quotients in selected Nigerian cities

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

Source apportionment and human health risk assessment of toxic trace elements in urban road dust

Ecological and Human Health Risk Assessment of Heavy Metal Contamination in Soils of a Former Auto-Mechanic Village in Old Nekede, Imo State, Nigeria

Soils were sampled from the decommissioned auto-mechanic village in Old Nekede, Owerri, Imo State, Nigeria, and analysed for six trace metals (Co, Ni, Fe, Zn, Pb and Al) in both the topsoil (0–15 cm horizon) and subsoil (15–30 cm horizon). Sampling stations were established at minimum inter-station distances of 100 m on a georeferenced grid. Ecological risk was assessed using the Hakanson potential ecological risk index (RI) and the monomial potential ecological risk factor (Er). Human health risk via ingestion, dermal contact, and inhalation pathways was calculated for adult and child receptors at each station following established USEPA protocols. Residual concentrations of Fe and Zn dominated the contamination profile, with topsoil Fe reaching 1,267.25 mg/kg and topsoil Zn reaching 253.00 mg/kg. Pb and Ni were below the analytical detection threshold (<0.001 mg/kg) at all stations. Ecological risk index values (RI) ranged from 13.9 to 59.0, classifying the site as low-to-moderate ecological risk, with the highest individual Er associated with cobalt. Non-carcinogenic hazard indices (HI) exceeded the USEPA threshold of 1.0 for child receptors at three of the five stations investigated, driven primarily by the ingestion pathway and attributable to Zn and Co. Cobalt carcinogenic risk remained within the USEPA acceptable range (10−6 to 10−4) for both receptor groups at all stations. Passive site recovery over five years post-relocation has proven insufficient. Findings support the need for ecological restoration, groundwater management, and enforceable land-use policy.

Human health risk of particle exposure in outdoor environments in southwestern Pennsylvania

Trace Metal Concentrations in Rainwater, Sources, and Health Risks: A Case Study of Hanoi, Vietnam

Atmospheric wet deposition, where pollutants, including metals, are washed from the atmosphere by rain, is a significant concern, particularly in urban and industrial areas, given the risks to human and ecosystem health. This study investigated the concentrations, sources, and potential health risk of 10 metals in 102 rainwater samples collected in Hanoi city during the period 2023–2025. The results showed that zinc-(Zn) was the most abundant metal, followed by iron-(Fe), manganese-(Mn), nickel-(Ni), copper-(Cu), lead-(Pb), chromium-(Cr), arsenic-(As), cadmium-(Cd), and mercury-(Hg). Although the mean values of these 10 metals were within the limits of the Vietnam technical regulation for drinking water, the maximal values of Fe, Mn and Pb were higher than the permissible values. Single-factor pollution index (Pi), and Nemerow pollution index (PN) showed a low pollution level of rainwater. Both the hazard index (HI) and the total carcinogenic risk demonstrated low potential health risks. Enrichment factor (EF) values revealed strong anthropogenic impacts on three metals (Hg, Cd, and Zn), whereas the remaining metals were from both natural and anthropogenic sources. Increasing population, urbanization, and industrial production, with the combustion of fossil fuel, domestic and agricultural waste, and urban construction, are probably major sources. Our results provide scientific evidence for policy-makers in environmental and ecosystem protection and provide data for the estimation of metal loads from wet deposition at regional and global scales. 10 rainwater metal concentrations were measured in Hanoi city in 2023–2025. Concentrations decreased in the order: Zn > Fe > Mn > Ni > Cu > Pb ~ Cr > As > Cd > Hg. Maximal values of Fe, Mn and Pb exceeded the limits for drinking water. Pi and PN indices revealed low pollution levels, whereas HI and total CR demonstrated low potential health risks. Hg, Cd, and Zn originated from anthropogenic activities, whereas the remaining metals were from both natural and anthropogenic sources. 10 rainwater metal concentrations were measured in Hanoi city in 2023–2025. Concentrations decreased in the order: Zn > Fe > Mn > Ni > Cu > Pb ~ Cr > As > Cd > Hg. Maximal values of Fe, Mn and Pb exceeded the limits for drinking water. Pi and PN indices revealed low pollution levels, whereas HI and total CR demonstrated low potential health risks. Hg, Cd, and Zn originated from anthropogenic activities, whereas the remaining metals were from both natural and anthropogenic sources.

 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.