Polycyclic aromatic hydrocarbon (PAH) contamination in clinical nutrition: Levels and associated health risks in enteral nutrition formulas.

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

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.

Beyond single scenarios: multi-scenario analysis of PAH exposure and health risks in China

Health Risk Assessment of PAHs in Processed Fish and Roasted Bovine Skin in Benin City, Nigeria

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. 

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.

Multi-Media Exposure, Selective Accumulation and Health Risks of Organochlorine Pesticides in Human Serum under Post-Ban Conditions

Organochlorine pesticides (OCPs), despite being banned, persist in the environment and continue to pose potential risks to human health. This exploratory study investigated the concentrations of multiple OCPs in serum samples from 10 local residents and 52 surrounding environmental samples, including soil (n = 10), air (n = 12), indoor dust (n = 10), and food (n = 20), collected in Taizhou, Zhejiang Province, in 2022. Multiple exposure pathways were quantified, and associated health risks were assessed. The results showed evidence of selective accumulation in humans, with serum ΣOCP concentrations ranging from 107.01 to 552.41 ng/g lipid weight (lw). p,p′-DDE was the predominant compound, accounting for 67.81% of total serum OCPs, while β-HCH showed relatively higher enrichment among HCH congeners. Lower proportions of p,p′-DDT and α-/γ-HCH were observed. Source contributions varied across media: food was the primary contributor to p,p′-DDE exposure, indoor dust and soil contributed more to β-HCH and certain DDT isomers, and the atmosphere showed a higher contribution of methoxychlor. Differences between integrated exposure profiles and serum composition highlighted the potential roles of metabolic transformation and lipid-associated accumulation in shaping internal OCP burdens. Risk assessment indicated that DDT metabolites and β-HCH were the major contributors to potential exposure risks. Overall, this study provides preliminary insights into the environmental–human distribution patterns of OCPs observed in Taizhou under post-ban conditions and highlights that environmental concentrations alone may not fully represent chronic internal exposure. These findings improve the understanding of potential OCP exposure pathways and emphasize the need for larger-scale studies incorporating population characteristics and refined exposure parameters for more comprehensive risk assessment

Pyrethroid residue concentrations and associated consumer health risks in fresh vegetables from Khon Kaen markets, Thailand

Background: Increased concerns over the potential health impacts on consumers from widespread pyrethroid use in agriculture have necessitated the implementation of maximum residue limits (MRLs) on food products. In Thailand, while such regulations exist, their enforcement remains incomplete.  The study aims to monitor pyrethroid contamination in Khon Kaen market vegetables and evaluate the risks posed to human health. Method: A total of 100 samples representing ten different fresh vegetable types were collected from May to July 2024. Pyrethroid residues in vegetables collected from both structured and unstructured markets in Khon Kaen, Thailand, were analyzed using gas chromatography (GC) with a micro electron capture detector (μECD). Health risks for both short-term and long-term exposure were calculated by combining the detected pyrethroid residue levels with estimated dietary intake data, utilizing a relevant database. Results: Samples of Chinese kale contained the highest levels of lambda-cyhalothrin detected at 0.71 mg/kg and bifenthrin at 0.70 mg/kg. The structured markets within Muang District had a high prevalence of detectable residues from pyrethroid groups. An evaluation of the short-term (sHI) and long-term (cHQ) health risks associated with the consumption of these vegetables indicates potential health risks exceeding acceptable thresholds, particularly among children. Conclusion: This investigation reveals pyrethroid contamination in vegetables from the Khon Kaen province markets in Thailand. It is vital to reduce contamination to ensure food security as well as educate consumers about this contamination to increase their food safety. Keywords: Pyrethroids, Pesticides, Maximum Residue Limits, Vegetables, Insecticide residues, Health risk assessment