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

Indoor Dust Investigation in Homes from Istanbul, Türkiye: Household Conditions, Heavy Metals, and Health Risk of PTEs

Seasonal assessment of heavy metal contamination, pollution indices, and human health risks in dumpsite soils of Abakpa bridge, Enugu State, Nigeria

This study assessed heavy metal contamination and associated ecological and human health risks at a municipal dumpsite using established pollution indices and risk models. Soil samples collected from three stations (A–C) during rainy and dry seasons were analyzed for Cd, As, Fe, Zn, Cr, Pb, and Hg. Results showed clear seasonal and spatial variations, with higher concentrations generally recorded in the dry season. Cadmium exhibited the highest contamination, with CF values ranging from 12.74–23.40 and EF values of 191.6–211.6, indicating very high anthropogenic enrichment. The Igeo values for Cd (3.09–3.96) classified the site as strongly polluted, while Pb showed moderate pollution (Igeo: 0.60–1.65). Other metals remained largely within unpolluted categories (Igeo ≤ 0). The degree of contamination (Cd) ranged from 16.74–31.78, indicating considerable contamination, while PLI values (0.51–1.01) suggested moderate overall pollution with localized deterioration. Ecological risk assessment identified Cd as the major contributor to risk, reflecting its high toxicity and elevated concentration. Human health risk assessment revealed ingestion as the dominant exposure pathway. The total hazard index (THI) for children (3.97 × 10²) was significantly higher than for adults (4.25 × 10¹), exceeding the safety threshold (THI > 1).  Arsenic and cadmium contributed most to risk, with ingestion HQ values of 205.3 and 70.0, respectively, for children. Dermal exposure contributed moderately, while inhalation was negligible (10⁻³).Overall, the dumpsite poses significant ecological and human health risks, necessitating improved waste management, environmental monitoring, and remediation strategies.

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.

 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.

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

Elemental composition of indoor dust and health risk assessment in preschools located in a seasonal haze-affected area: Lampang Province, Thailand

This study investigated trace element contamination, source characteristics, and associated health risks of indoor dust collected from 22 preschools across six districts of haze-affected Lampang Province, Thailand. Dust samples from urban, coal power plant, sub-urban, and rural areas were analyzed for As, Cr, Ni, Pb, Cu, Fe, Mn, Zn, and K using ICP-OES following acid digestion. Contamination levels were evaluated using the enrichment factor (EF), geo-accumulation index (Igeo), and potential ecological risk index (RI), while human health risks were assessed using non-carcinogenic (HQ, HI) and carcinogenic (CR, TCR) models. Fe, K, Zn, and Mn were the dominant elements, with Zn showing moderate contamination and strong anthropogenic influence, particularly from traffic emissions and biomass burning. Source apportionment indicated mixed contributions from soil dust, industrial activities, and combustion processes. Ecological risk remained low across all sites (RI < 150). Non-carcinogenic risks were negligible (HI < 1), although children were more susceptible than adults. Carcinogenic risks for As, Cr, and Ni through both ingestion and inhalation pathways were within acceptable limits (10-6 to 10-4), with ingestion representing the dominant exposure pathway. Overall, indoor dust posed low ecological and health risks; however, continued monitoring is recommended due to potential long-term exposure effects on children.