Spatial distribution of heavy metals in seawater and age-specific health risks to swimmers at Tirang Beach, Indonesia.

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

The disease burden associated with air pollution is now comparable to that of other major global health threats, including poor nutrition and tobacco use. This study employed the gravitational settling method to collect airborne particles in selected Nigerian cities. The cities include; Benin, Kano, Abuja, Lagos, Enugu, and Calabar. Airborne particles were allowed to settle naturally into containers fitted with funnels and placed outdoors at various sub-locations within each State. Sampling was conducted over a nine-month period from January to September 2023. The collected sediments were analyzed spectroscopically using a UV Visible (UV-VIS) Spectrophotometer CE 1101 to determine concentrations of cadmium (Cd), nickel (Ni), lead (Pb), and manganese (Mn). Results revealed that hazard quotient (HQ) values for all analyzed metals exceeded the recommended safe limit of 1 across all locations. In Benin City, nickel and lead recorded HQ values of 5.5 and 4.0, respectively. Enugu showed particularly elevated levels, with manganese (Mn) at HQ 16 and lead (Pb) at HQ 5, attributed to industrialization and vehicular activities. In Kano, HQ values for lead (Pb) and nickel (Ni) were 8.0 and 4.9, respectively. Abuja recorded HQ values of 6.0 for lead (Pb) and 4.9 for nickel (Ni), likely linked to recycling and agricultural activities. Lagos and Calabar also exhibited elevated HQ values, particularly for lead and nickel. Elevated exposure to these toxic elements can pose potential health risks, including neurological, respiratory, and allergic effects, to exposed populations.

Spatial and temporal patterns of trace metal distribution and ecological risk in a coal-mined central appalachian watershed, USA

Distribution, Source Apportionment, and Risk Assessment of Heavy Metals in Surface Waters from a Glacier Basin on the Southeastern Tibetan Plateau

Heavy metals in surface waters pose significant risks to aquatic ecosystems and human health. In this study, a comprehensive analysis of multiple heavy metals (V, Cr, Mn, Co, Ni, Cu, Zn, As and Cd) was performed using extensive surface water samples from the Meili Snow Mountains glacier basin, southeastern Tibetan Plateau. Results showed that heavy metal concentrations were higher in glacier meltwater than in downstream rivers, with significant variability observed in both the glacier basin (0.00300–33.4 μg/L) and downstream rivers (0.00500–2.85 μg/L), attributable to local geological processes and regional atmospheric deposition of transported particulate pollutants. Elevated total heavy metal concentrations at Sinong River and Qunatong River were primarily driven by uneven distribution of specific metals, likely from both anthropogenic and natural sources. Principal component analysis extracted three components that grouped heavy metals into Mn–Co–Ni–Cd, Cu–Zn, and V–Cr associations, indicating mixed geogenic and anthropogenic sources, with long-range atmospheric transport from surrounding polluted regions being a notable contributor. Risk assessments indicated low ecological risks (ERI < 150) and safe non–carcinogenic risks (HI < 1), with children exhibiting higher susceptibility than adults and As being the primary contributor. Although the carcinogenic risks (TCR: 10−6–10−4) were acceptable, ingestion of As and Ni posed higher risks, especially in the Yubeng River basin for adults. These findings provide valuable insights for water resource management and health protection in the southeastern Tibetan Plateau.

Spatio-seasonal groundwater heavy metal contamination and health risks in West Sheger city, Ethiopia: integrated APCS-MLR-PMF approach

Infographic comparing seasonal groundwater contamination in West Sheger City. In dry season, low rainfall and stable cadmium (Cd) combine with arsenic (As) to drive risk; children face higher non-carcinogenic risk than adults. In wet season, rising arsenic (Pb) from agriculture and industry exceeds WHO limits. Groundwater contamination by toxic elements poses health risks in water-limited regions, yet seasonal monitoring and source identification remain limited. This study evaluated the spatioseasonal variation of heavy metals, identified pollution sources, and assessed health risks in West Sheger City (spanning three subcities), Ethiopia. Twenty-four groundwater samples were collected during dry and wet seasons and analyzed for As, Hg, Cd, and Pb. Absolute principal component scores–multiple linear regression and positive matrix factorization (PMF) receptor models, cluster analysis, and principal component analysis were applied to resolve patterns, and with source-factor selection guided by diagnostic criteria and optimized PMF solutions. Pollution indices indicated contamination. Arsenic exceeded World Health Organization guideline values in the wet season, while Pb concentrations were higher in the dry season near identified sources; Cd remained stable under low-oxygen conditions. Mapping identified persistent contamination hotspots. Four sources: industrial, agricultural, geogenic, and atmospheric were identified, with seasonal variability. Health risk assessment indicated non-carcinogenic risks from drinking water, with greater susceptibility in children. Cd and As dominated risk during the dry season, whereas Pb predominated in the wet season. Risk estimates were evaluated using Monte Carlo simulation (10,000 iterations) to characterize uncertainty and variability. Seasonal pollutant-specific management and prioritization required to reduce exposure.

Health risk profiles of heavy metals and radionuclides in geothermal waters and groundwater, Kanchanaburi Province, Thailand: An interannual comparative baseline assessment.

Geothermal systems of Kanchanaburi Province in western Thailand constitute important hydrothermal resources yet represent potential reservoirs of geogenic contaminants. Despite increasing utilization, the combined health risks posed by heavy metals and naturally occurring radionuclides under variable hydrogeochemical conditions remain poorly understood. This study presents an integrated, interannual comparative assessment of trace constituents in major geothermal springs and adjacent groundwater, based on datasets collected in November 2023 and November 2024. The analytical results indicate persistent localized contamination, with mercury (Hg) and radium-226 (Ra-226) exceeding Thai regulatory standards and WHO drinking water guidelines at specific thermal sites. Health risk modeling for adult receptors revealed a distinct interannual shift in the risk profile. In 2023, non-carcinogenic risks were unacceptable (Hazard Index >1), primarily driven by Hg toxicity. Conversely, in 2024, while non-carcinogenic risks declined, carcinogenic risks (CR) increased to unacceptable levels (CR > 1 × 10-4), driven by the elevated presence of arsenic (As). These findings demonstrate that static, single-point assessments may inadequately characterize for managing geochemically complex systems. Consequently, periodic monitoring strategies are essential to safeguard public health against such interannual variations in toxicological threats.

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

The present study concerns the geographical assessment of atmospheric airborne heavy metals in the main monitoring stations of Baghdad during the months of May and June 2025. The heavy metals of interest are Lead (Pb), cadmium (Cd), nickel (Ni), Iron (Fe), Copper (Cu) and zinc (Zn). Air samples were collected with standardized one hour sniffer-based sampling, and the levels of heavy metals were determined in a laboratory. Geostatistical mapping and spatial interpolation were used to visualize distribution patterns and pollution hotspots across the metropolitan landscape. Results show a clear spatiotemporal variability driven by sources of legacy contamination, seasonal weather, industrial pollutants and traffic intensity. In both months, high atmospheric dispersion of river-channel airflow dynamics resulted in continually lower levels of heavy metals in the areas along the Tigris River, especially in central Al-Karkh and parts of Al-Khadimiya. However, high Zn concentrations, above 14 ppm in May, were observed near Karadaa and Al-Zafaraniya where there is a lot of traffic, construction and private generator use. Most of the metals showed higher concentrations in May (e.g., Cr: 0.84–2.31 ppm) than in June (0.231–1.16 ppm) which can be indicative of seasonal changes in air stability and emission strength. Fe showed the opposite trend, increasing from 4.05-9.91 ppm in May to 6.06-10.2 ppm in June. This increase was probably because of stronger summer winds and increased dust resuspension. Furthermore, spatial maps show much lower Fe concentrations along the Tigris corridor, supporting the moderating effect of dispersion due to river transport. The results show the combined impact of seasonal weather patterns and anthropogenic emissions on airborne metal pollution in Baghdad and highlight the urgent need for focused air quality control measures in high exposure areas