Dietary Daily Intake, Toxic Equivalent Concentrations, and Excess Cancer Risk of Polycyclic Aromatic Hydrocarbons in Tympanotonus fuscatus Harvested from Woji– Elelenwo Creek, Rivers State, Nigeria
2026· Journal of Applied Sciences and Environmental Management· 0 citations
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental contaminants of concern due to their toxicity, carcinogenicity, and potential for bioaccumulation in aquatic organisms. This study evaluated the concentrations, sources, and human health risks of PAHs in periwinkle (Tympanotonus fuscatus) from the Woji–Elelenwo Creek, Niger Delta, Nigeria. Periwinkle samples were analyzed for sixteen priority PAHs using standard analytical methods, while dietary exposure and carcinogenic risks were assessed using established risk assessment models. Results showed that high molecular mass PAHs predominated over low molecular mass PAHs, indicating the persistence of combustion-derived hydrocarbons within the creek ecosystem. The mean total PAH concentration was 0.472 mg/kg, while carcinogenic PAHs contributed 0.388 mg/kg of the total burden. Fluoranthene recorded the highest mean concentration (0.098 ± 0.156 mg/kg), followed by benzo(b)fluoranthene (0.070 ± 0.157 mg/kg), chrysene (0.056 ± 0.114 mg/kg), and benzo(a)anthracene (0.056 ± 0.114 mg/kg). The PAH4 index and total toxic equivalency (TEQ) were 2.08 × 10⁻² mg/kg and 6.89 × 10⁻² mg/kg, respectively, with dibenz(a,h)anthracene contributing most to the toxic burden. Estimated dietary daily intake values were below international guideline limits, while the excess cancer risk (6.51 × 10⁻⁷) indicated negligible carcinogenic risk to consumers. Diagnostic ratios suggested predominantly petrogenic contamination with minor pyrogenic inputs linked to hydrocarbon-related activities. Although current health risks associated with periwinkle consumption appear low, the occurrence of carcinogenic PAHs highlights ongoing hydrocarbon pollution in the creek. Continuous environmental monitoring and pollution control measures are therefore recommended. This study provides baseline data for environmental management and risk assessment in the Niger Delta.
This study aimed to determine the levels of 16 priority PAHs in commercial enteral nutrition formulas (ENFs) marketed in Türkiye and to assess dietary exposure and associated carcinogenic and non-carcinogenic health risks under different consumption scenarios. Across all products, most PAH concentrations were either below the limit of detection or present only at trace levels, demonstrating very low contamination. Although a limited number of samples showed relatively higher concentrations of high-molecular-weight PAHs, such as ∑4PAHs reaching up to 3.06 μg/kg and ∑16PAHs up to 5.48 μg/kg, overall PAH levels remained low and did not suggest significant toxicological concern. Exposure modelling demonstrated that estimated PAH intakes were negligible in both partial- and full-dependence consumption scenarios (A and B, respectively). Hazard Index values remained well below the threshold for non-carcinogenic effects (Reference value: 1), while Incremental Lifetime Cancer Risk values fell within negligible ranges (3.55×10-8-4.76×10-7). The Margin of Exposure calculations (1,854,054-249,000,000) further supported the absence of carcinogenic concern, remaining well above the benchmark across all PAH groupings. These findings collectively suggest that currently marketed ENFs do not pose a significant PAH-related health risk for adult consumers. However, given the vulnerability of ENF users, continued monitoring of raw materials, processing, and packaging remains warranted to ensure product safety.
B. Başaran, O. Canlı, Barış Güzel· Regulatory toxicology and ph...· 0 citations
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.
Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants with potential health risks, particularly in food. This study assessed the PAH levels present in processed bovine skin (kpomo) and grilled fish and their related health risks. Ten (10) kpomo and 10 grilled fish samples were collected from different vendors and analysed using gas chromatography-mass spectrometry. Health risk assessments were carried out based on estimated daily intake (EDI), hazard quotient (HQ), hazard index (HI), and cancer risk index (CR). Results showed that fluoranthene was the only PAH detected in kpomo samples, with concentrations ranging from 0.039 mg/kg to 0.125 mg/kg. In grilled fish samples, PAH levels ranged from 0.012 mg/kg (Benzo(b)fluoranthene) to 0.764 mg/kg (Indeno(1,2,3) perylene), with only two samples showing contamination. HQ and HI values indicated minimal non-carcinogenic risks for most food samples; however, children exposed to certain fish samples (ZE) had an HI > 1, suggesting potential adverse health effects. The cancer risk assessment showed generally low carcinogenic risks, except for a sole processed fish sample (ZE), where HI values exceeded 1 × 10⁻³ for children. These findings revealed the need for continued monitoring of PAHs in food products, improved processing techniques, and stricter food safety regulations to minimize health risks, particularly for vulnerable human populations.
This study aimed to quantify the levels of mercury (Hg), arsenic (As), lead (Pb), and cadmium (Cd) in 250 fish samples, including flathead grey mullet, sardine, and mackerel, collected from local fish markets in Mansoura, Egypt, on ten occasions from August 2023 to March 2024. Unlike previous studies that have primarily focused on metal concentrations, this study assessed both carcinogenic and non-carcinogenic health risks among the general population (57.09 g/day) and high-fish consumers (200 g/day). Metal concentrations were determined using atomic absorption spectrophotometry, with method accuracy validated using certified reference materials (CRMs), yielding recoveries of 95.5–100.6%. The average concentrations of Hg, As, Pb, and Cd (µg/g wet weight) were 0.313, 2.13, 0.194, and 0.018 in flathead grey mullet (As > Hg > Pb > Cd); 0.131, 1.65, 0.472, and 0.021 in sardine (As > Pb > Hg > Cd); and 0.196, 0.98, 0.370, and 0.025 in mackerel (As > Pb > Hg > Cd), respectively. Hg and As concentrations were significantly higher in flathead grey mullet, whereas Pb concentration was highest in sardine and Cd concentration was highest in mackerel. Based on the Maximum Permissible Limits (MPLs) set by the Food and Agriculture Organization (FAO), Egyptian Organization for Standardization and Quality (EOS), and Food Standards Australia New Zealand (FSANZ), the proportion of samples exceeding these limits ranged from 9 to 20% for Hg, 22–56% for As, and 20–58% for Pb. For the general population, only the estimated daily intake (EDI) of Hg in flathead grey mullet was above the Provisional Tolerable Daily Intakes (PTDIs), while EDI of most metals exceeded safety thresholds in high fish consumers. Target Hazard Quotient (THQ) for Hg and As exceeded 1.0, while TTHQ values for flathead grey mullet, sardine, and mackerel were 8.4, 5.7, and 4.35 for the general population and 29.43, 19.84, and 15.26 for high-fish consumers, respectively, indicating potential non-carcinogenic health risks. Furthermore, cancer risk (CR) for As ranged from 1.20E−03 to 9.14E−03, exceeding the acceptable safety threshold of 1.0E−04, whereas Pb and Cd risks remained within safe limits. The relatively high metal concentrations may reflect anthropogenic pollution and other environmental inputs affecting the aquatic ecosystem, highlighting the need for regular monitoring and control of pollution sources to reduce contamination and protect public health.
H. Elshebrawy, K. Sallam, Nahed Kasem et al.· Scientific Reports· 0 citations
In this study, the concentrations, compositional patterns, sources, and human health risks of polycyclic aromatic hydrocarbons (PAHs) were investigated in surface sediments and the oyster Saccostrea cucullata collected from five tidal beach stations along the Oman Sea. Total PAH concentrations in surface sediments ranged from 171 to 533 ng g-1 dw, whereas markedly higher levels were recorded in oyster tissues (1064-4219 ng g-1 dw), indicating substantial bioaccumulation. A significant positive correlation was observed between PAH concentrations in sediments and corresponding oyster tissues (p < 0.05), and both matrices exhibited similar compositional patterns, suggesting that sediment contamination directly influences PAH accumulation in oysters. Source diagnostic ratio analysis indicated a predominance of petrogenic sources, with low-molecular-weight PAHs being more abundant than high-molecular-weight compounds in both sediments and oysters. Although the EDI values were below the recommended threshold levels, the presence of PAHs in oysters reflects their bioavailability in the coastal environment and warrants continued monitoring. Given the bioaccumulation of PAHs in bivalves and the associated human health risks, long-term biomonitoring programs using bivalves are strongly recommended to support pollution mitigation efforts and ensure seafood safety.
Reza Dahmardeh Behrooz, Sanaz Khammar, K. Nambirajan et al.· Marine Pollution Bulletin· 0 citations
Polycyclic aromatic hydrocarbons (PAHs), typical persistent organic pollutants, are ubiquitous around coking plants and pose potential ecological and human health risks. This study used readily available willow leaves collected from areas surrounding a coking plant as a passive sampling medium to investigate PAH accumulation characteristics and evaluate their feasibility as bioindicators. The results showed that PAH concentrations in willow leaves were relatively high, indicating a strong accumulation capacity for atmospheric PAHs. A significant positive correlation was observed between the logarithm of the leaf-air partition coefficient (KLA) and the logarithm of the octanol-air partition coefficient (KOA) (R2 = 0.6170, p < 0.001). Further analysis of concentration correlations and toxic effects revealed that, among individual PAHs, naphthalene exhibited the strongest correlation with total PAH concentration (R2 = 0.6375), although it was insufficient to represent the overall PAH pollution level. Toxic equivalency analysis indicated a strong relationship between the toxic equivalent concentration of benzo[a]pyrene (TECBaP) and the total toxic equivalent concentration (TTEC) (R2 = 0.9387). Leave-one-out cross-validation (LOOCV) further demonstrated good internal robustness of the model (RMSE = 0.157). Overall, under the specific meteorological and source conditions during the sampling period of this study, BaP can serve as a surrogate indicator for the rapid estimation of the total toxic equivalent concentration of PAHs in willow leaves. However, the applicability of this indicator is source-dependent and should be further validated under different plant species, meteorological conditions, and emission source scenarios before broader application.
Guohui Xia, Yuan Gao, Handan Zhang et al.· Journal of Environmental Man...· 0 citations