Aug 2026· Toxics· Vol 14· 0 citations· 60 references
Medicine
Abstract
Ambient exposure to fine particulate matter (PM2.5) remains a critical global public health concern; however, the speciation and bioaccessibility mechanisms of particle-bound heavy metals within the lung environment are still insufficiently understood. In particular, the role of soluble and insoluble metal species in simulated lung fluids requires further clarification. Road dust, a major contributor to PM2.5, contains heavy metals that pose significant inhalation risks, leading to oxidative stress, DNA damage, and systemic toxicity. This study investigated the contamination characteristics, bioaccessibility, pollution level, and speciation of heavy metals in PM2.5-fractionated road dust (PM2.5RD) collected from Karachi (a megacity with >27 million inhabitants) and Shikarpur (a medium-sized city of ~0.3 million) in Pakistan. A grid-based sampling approach was applied across four functional zones (residential, school, hospital, and office), yielding 48 samples. Inhalation bioaccessibility was evaluated using artificial lysosomal fluid (ALF; pH 4.5, 37 °C, 24 h), revealing moderate bioaccessibility of Cr, As, and Pb. Pollution status was assessed using contamination factor (CF), integrated pollution index (IPI), pollution load index (PLI), and potential ecological risk index. Geochemical modeling with PHREEQC 3.0 and Visual MINTEQ 3.1 was employed to simulate metal speciation, release behavior, and mineral saturation states. Overall, this study provides mechanistic insights into speciation-driven toxicity of As, Pb, and Cr in simulated lung environments, offering a scientific basis for improved risk assessment and regulatory strategies for PM2.5-associated metal exposure.
The results highlighting the need for continued source control in school environments, with special attention to nonexhaust traffic emissions and industrial combustion, highlight the need for continued source control in school environments.
Haseeb Tufail Moryani, Fu Wang, Yang Zhou et al.· Journal of Applied Toxicolog...· 0 citations
Findings identify Cr containing PM2.5 inhalation during haze episodes as a priority health concern, particularly for children, underscoring the need for targeted emission controls in semi-urban-agricultural areas.
T. Srithawirat, Chanikan Junmatong, Orachorn Chimjan et al.· Journal of Environmental Sci...· 0 citations
Size-fractionated particulate matter analysis is key to understanding how particle size influences health risks. However, data on metals distribution and respiratory deposition across PM sizes in Southeast Asia is still scarce. In this study, we evaluated the levels, size distribution, and health-related impacts of metals in particulate matter (PM) from Ho Chi Minh City (HCMC), the most densely populated urban in Southern Vietnam. Sampling was performed monthly with a five-stage nano-sampler (PM< 0.5, PM0.5−1, PM1−2.5, PM2.5−10, and PM> 10). Concentrations of 8 metals were analyzed by ICP-MS, and the levels were observed in the following order: Al (1741 ng m− 3) > Fe (958 ng m− 3) > Zn (731 ng m− 3) > Pb ( 22.6 ng m− 3) > Mn (21.3 ng m− 3) > Cu (19.4 ng m− 3) > Ni ( 4.86 ng m− 3) > Cd (0.52 ng m− 3). Crustal metals (Al and Fe) predominantly resided in the coarse particulate fraction, whereas anthropogenic metals (e.g. Pb, Zn, and Cd) were enriched in fine particles. Deposition modeling indicated that crustal metals were mostly retained in the head region (62–72%), while anthropogenic metals were deposited more in deeper lung regions (7–12%). The health risk assessment showed that the Hazard Index (HI) was markedly higher in children than in adults for both PM2.5 and PM10. Specifically, the HI for children was 1.95 for PM2.5 and 3.54 for PM10, whereas for adults, these values were 0.49 and 0.88, respectively. Regarding cancer risk, Total Cancer Risk (TCR) for children reached 1.31 × 10− 5 for PM2.5 and 1.75 × 10− 5 for PM10, exceeding the low-risk threshold. In contrast, the TCR for adults was considerably lower at 3.26 × 10− 6 and 3.0 × 10− 6. These findings indicated the importance of size-resolved PM studies to better understand exposure characteristics and potential health risks posed by toxic elemental contaminants.
Le Quoc Hau, D. Nguyen, Nhung T. Tuyet Hoang et al.· Journal of Atmospheric Chemi...· 0 citations
Abandoned mine tailings, rich in potentially toxic elements (PTEs), can be redistributed in urban areas through atmospheric resuspension. This process serves as a dynamic geochemical compartment linking legacy contamination to human exposure. This study investigated the occurrence, oral bioaccessibility, ecological significance, and human health risks of PTEs in urban dust from Boquira, a former Pb–Zn mining district in northeastern Brazil. Eighteen urban dust samples and reference soils from uncontaminated areas were collected and analyzed for pseudo-total concentrations of Pb, Zn, Cd, Cu, Mn, Fe, and Al. Analyses were conducted using microwave-assisted acid digestion and X-ray fluorescence spectrometry (XRF). Geochemical indices, including the geoaccumulation index (Igeo), contamination factor (CF), enrichment factor (EF), and ecological risk index (Er), were used to evaluate anthropogenic enrichment and its ecological implications. Oral bioaccessibility was assessed using a simplified dilute nitric acid extraction method that simulates gastric conditions. Elevated enrichment and contamination indices revealed substantial anthropogenic inputs, particularly for Pb and Zn, indicating the long-term environmental persistence of mining-derived particulates. Pb had the highest mean oral bioaccessibility (~ 75%), followed by Cu (54.8%), Mn (28.1%), and Zn (27.0%), indicating the predominance of highly reactive and physiologically available metal-bearing phases. Human health risk assessment identified oral ingestion as the dominant exposure pathway, compared to dermal exposure, with children presenting substantially higher risks than adults. Non-carcinogenic risk thresholds (HI > 1) were exceeded for children, primarily due to Pb exposure, whereas carcinogenic risk associated with Cd ingestion exceeded acceptable limits for both population groups. The results demonstrate that legacy mine tailings in Boquira remain environmentally active decades after mine closure, sustaining chronic atmospheric redistribution of bioaccessible PTEs into urban areas.
Edvaldo Renner da Costa Cardoso, Rugana Imbaná, Ésio de Castro Paes et al.· Environmental Monitoring & A...· 0 citations
The results of the total carcinogenic risk for children aged 7–12 years in all schools caused by the presence of PAHs compounds in outdoor environments was acceptable and in some indoor environments, the values at certain schools exceeded the standard threshold of 10− 6-10− 4, indicating potential health risks.
Mohamad Firdaus Ismail, M. F. Fadzil, Nur Atifah binti Mohd Naim et al.· Asian Journal of Atmospheric...· 0 citations
PM10 (particles with aerodynamic diameter ≤ 10 μm) is a carrier of toxic elements from diverse sources. This study examined the origin and potential health risks associated with trace elements in PM10 during the dry season in Ghana. A Gent sampler, equipped with a Gast pump and a stacked filter unit, was employed to collect airborne particulates at the Winneba Highway Intersection (WHI) and the Apam Fish-smoking Community (AFC). Sampling was conducted three times per week from November 2022 to March 2023, with each session lasting 24 h. The particulate samples were analysed for elemental and Black Carbon (BC) concentrations using Ag-anode X-ray tube spectrometer and a smoke stain reflectometer, respectively. The US EPA Air Quality Index (AQI) and health risk assessment models evaluated air quality and elemental toxicity risks, respectively. Notably, the average levels of Chromium (77 ng/m3) and Nickel (210 ng/m3) at WHI, and Chromium (310 ng/m3) and Nickel (470 ng/m3) at AFC, exceeded the US EPA threshold limits. Pearson’s correlation model linked BC, sulphur, and potassium to combustion-related emission sources. Principal Component Analysis (PCA) showed that PM10 at WHI originated from fugitive dust and sea salt, vehicular emissions, and minor industrial activities, whereas sea salt, dust, biomass burning, and vehicular emissions contributed to PM10 at AFC. AQI ratings indicated moderate air quality during December to February, implying potential health risks for sensitive populations. Cancer risk levels were relatively higher in adults than in children. Adopting clean fuels and sustainable transport is vital to reducing PM₁₀ health risks.
Francis Attiogbe, G. Safo-Adu, F. Ofosu et al.· Asian Journal of Atmospheric...· 0 citations
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