Comparative Assessment of Polycyclic Aromatic Hydrocarbon Levels in Indoor and Outdoor Air and Associated Inhalation Health Risks in Akpajo, Alesa and Aleto Communities, Eleme, Rivers State, Nigeria

Unveiling distribution and health risks of polycyclic aromatic hydrocarbons (PAHs) bound to PM2.5 in indoor and outdoor environments of urban primary schools

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.

Polycyclic Aromatic Hydrocarbon (PAHs) Pollution Status of Soil, Water, and Edible Vegetables Within Cashew Nut Processing Clusters in Enugu, Nigeria

This study evaluated the concentrations of polycyclic aromatic hydrocarbons (PAHs) in soil, water, and edible plants within cashew nut processing clusters in Enugu, Nigeria. Following liquid–liquid and solid–liquid extractions, the concentration of sixteen PAHs congeners were determined using gas chromatography coupled with a flame ionization detector (GC‐FID). To predict the potential sources of these PAHs, a diagnostic ratio guide was employed and principal component analysis was performed. Mutagenic equivalent concentration, human health risk assessment, and ecological risk assessment were performed. The identified PAHs had concentration range: 786.31–2589.46 µg/kg in soil, 33.78–5476.37 µg/L in water, and 561.47–3047.84 µg/kg in vegetables. Except for one location, the vegetables had higher levels of low molecular weight PAHs, while high molecular weight PAHs were more prevalent in the water. The results showed that the studied location has a fair amount of PAH pollution, mostly from pyrogenic sources though the source apportionment models predicted multi‐sources. The ecological risk assessment indicated acenaphthene to be the most contributing contaminant while the health risk evaluations indicated that consumers of water and vegetables from this area may have risk for non‐carcinogenic health problems. There were substantial mutagenic equivalent quantities, and BaP metabolites were probably responsible. The study reveals that inefficient burning of biomass and fossil fuels has resulted in significant levels of PAH contamination in the surrounding cashew nut processing clusters, and these activities should be controlled.

Rising Carcinogenic Risk from Polycyclic Aromatic Hydrocarbon Exposure Through Indoor Settled Dust: First Comprehensive Residential Dust Assessment from India

Occurrence, Health Risk and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Borehole Water Around Fuel Stations in Owerri West Local Government Area, Imo State, Nigeria

Borehole water is a major drinking water source in Owerri West LGA, Imo State, Nigeria, but fuel stations within residential areas raise concerns over groundwater contamination by polycyclic aromatic hydrocarbons (PAHs). This study assessed concentrations of the 16 USEPA priority PAHs in borehole water near three fuel stations (Nekede, Orogwe, Obinze), evaluated health risks to adults and children, and identified probable contamination sources. Twenty-seven samples were collected in the dry season from fuel-station and nearby residential boreholes (25–625 m away). Physicochemical parameters were analyzed per APHA (2017); PAHs were extracted (USEPA Method 3510C) and quantified by GC-MS. Health risk was assessed using the USEPA (2014) deterministic model, with source apportionment via diagnostic ratios and PCA. All physicochemical parameters met WHO/USEPA limits. Total PAHs (Σ16PAHs) ranged from 0.112–0.217 mg/L, with benzo(a)pyrene exceeding the USEPA limit (0.01 µg/L) in all fuel-station boreholes. Hazard quotients were below 1, but benzo(a)pyrene cancer risk (7.15×10⁻⁵ adults; 1.67×10⁻⁴ children, Nekede) exceeded the USEPA threshold (1×10⁻⁶), with children ~2.3 times more at risk. Diagnostic ratios indicated predominantly pyrogenic sources with petrogenic contribution from fuel leaks. Despite meeting potability standards, the water posed unacceptable carcinogenic risk, warranting setback regulations and household treatment.

Soil Quality, Pollution Indices and Health Risk of Metals and PAHs at a Crude-Oil Spill Site in Okpohovor, Delta State, Nigeria

Background: Oil spillage is a major driver of soil degradation in the Niger Delta, yet integrated, site-specific assessments coupling metals, polycyclic aromatic hydrocarbons (PAHs) and quantitative risk remain scarce. Objective: This study assessed the contamination status, source structure and ecological and human-health risk of soils at a crude-oil spill site in Okpohovor, Udu Local Government Area, Delta State, Nigeria. Methods: Soils from five points (S1–S5) and a control station were sampled at two depths (0–15 and 15–30 cm). pH, electrical conductivity, total organic carbon, particle size and nine metals were determined by flame atomic absorption spectrophotometry, and 16 priority PAHs by GC–MS. Pollution indices, principal component analysis (PCA), one-way ANOVA with effect sizes, and BaP-equivalent, hazard-index and incremental lifetime cancer-risk models were applied. Results: Soils were strongly acidic (pH 3.00–3.70) and sandy. All metals were below Department of Petroleum Resources (DPR) target values except cadmium (0.05–2.55 mg/kg), which reached the pollution range in 60% of samples. Clay differed significantly between sites (F=10.133, p=0.013, η²=0.890). PCA separated a lithogenic Pb–Cr–Ni–Fe association (PC1, 32.0%) from a cadmium-driven signal. The ecological risk index (9–263) was cadmium-dominated. ΣPAH reached 81,327 µg/kg from mixed petrogenic–pyrogenic sources; hazard indices were mostly below 1 but total cancer risk exceeded 1×10⁻⁶. Conclusion: Cadmium and carcinogenic PAHs are the priority contaminants, posing food-chain and public-health risks that warrant targeted remediation and sustained monitoring.

Spatial and seasonal variability of atmospheric persistent organic pollutants in northeastern France: passive air sampling and source patterns.

Persistent and semi-volatile organic contaminants remain important atmospheric tracers because of their environmental persistence, multiple emission pathways and capacity for regional transport. This study investigated the spatial and seasonal variability of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in northeastern France. Nitrogen-doped carbon-coated silicon carbide foam (NMC@SiC) passive air samplers were deployed at six urban, suburban and rural sites in the Strasbourg metropolitan area between 2018 and 2020. Twenty-one OCPs, sixteen PAHs, and twenty-two PCBs were quantified by gas chromatography-tandem mass spectrometry. PAHs exhibited the clearest spatial and seasonal variability, with higher concentrations at urban sites and cold-season or autumn enhancements depending on the location. Naphthalene dominated the PAH profile, while diagnostic ratios suggested dominant combustion inputs, including traffic, residential heating and biomass or solid-fuel burning. PCBs showed weaker spatial contrasts and more homogeneous distributions, with profiles dominated by penta-, hexa- and hepta-chlorinated congeners, indicating diffuse legacy contamination, possible PCB-containing materials, industrially influenced areas and regional redistribution. OCPs were dominated by dichlorodiphenyltrichloroethane-related compounds and hexachlorocyclohexane isomers, reflecting historical residues and secondary volatilization from contaminated environmental reservoirs. These findings highlight the combined influence of current urban emissions, persistent legacy reservoirs, secondary re-emissions and regional atmospheric transport on organic contaminant distributions in northeastern France.