Recent Evidence on Polycyclic Aromatic Hydrocarbon Exposure

Associations between urinary polycyclic aromatic hydrocarbon biomarker concentrations and birth outcomes in the LIFECODES cohort

Environmental exposure to polycyclic aromatic hydrocarbons (PAH) is ubiquitous and may impact fetal development leading to adverse birth outcomes. PAHs result from incomplete combustion and exposure sources include inhalation of cigarette smoke and car exhaust, ingestion of charred meat, and many others. The purpose of this study was to determine associations between prenatal PAH biomarker concentrations and birth outcomes. Our nested case-control study included 123 preterm birth cases and 335 term controls from the LIFECODES cohort between 2006 and 2008 (n = 458). Eight urinary PAH metabolites were measured in urine samples collected at up to four study visits (median 12, 18, 24, 34 weeks gestation). Linear and logistic regression were used to model gestational geometric mean PAH biomarker concentrations in relation to preterm birth, birth weight z-score, and small or large for gestational age with adjustment for potential confounders. Effect modification by infant sex was also explored. Odds ratios for preterm birth were elevated for most PAH metabolites but confidence intervals included the null. For most PAH metabolites, a significant inverse association was observed for birth weight for gestational age z-score, and a corresponding increase in the odds of small for gestational age (SGA). For example, an interquartile range increase in 2-hydroxynapthalene (2-NAP) was associated with a significantly lower birth weight z-score (β: 0.22; 95 % CI: 0.36, -0.08) and 1.90 times the odds of SGA (95 %CI: 1.41, 2.55). Further study should aim to determine the extent and mechanisms by which PAH exposure impacts fetal growth.

Occurrence, formation mechanism, and health risk of polycyclic aromatic hydrocarbons in barbecued food

Polycyclic aromatic hydrocarbons (PAHs) show negative impacts on human health. Dietary intake is the predominant way for PAH exposure, of which barbecued food is a crucial contributor. This review aims to provide a comprehensive insight into the formation mechanism, influencing factors, mitigation strategies, and health risks of PAHs in barbecued food. PAHs in barbecued food are formed by Hydrogen abstraction and acetylene addition (HACA) mechanism, Diels-Alder reaction and Maillard reaction, which was influenced by heat source, temperature, cooking time, and the meat type. There are significant differences in PAH concentrations in different barbecued foods, where chrysene dominates among the selected PAH species. To reduce PAHs formation, adding marinades and adopting alternative cooking methods are suggested, which effectively reduce PAH levels by 53 -89 %. In addition, it is estimated that people in countries such as Pakistan has an incremental lifetime cancer risk (ILCR) over 10-5 via barbecued food consumption, indicating potential health risk. This work highlighted that regular monitoring of PAH levels in barbecued food and dynamic modification of relevant safety limits are recommended to ensure food safety.

Computational Multiscale Study of the Interaction Between the PDMS Polymer and Sunscreen-Related Pollutant Molecules

Sunscreen molecules play a critical role in protecting skin from ultraviolet radiation, yet their efficient detection and separation pose challenges in environmental and analytical contexts. In this work, we employ a multilevel modeling approach to investigate the molecular interactions between representative sunscreen molecules and the polydimethylsiloxane (PDMS) polymer, a material widely recognized for its sorbent properties. Our goal is to explore how these interactions can be fine-tuned to facilitate the effective separation of sunscreen molecules in portable membrane inlet mass spectrometry (MIMS) systems, potentially leading to the development of new membrane materials. Using a combination of advanced computational techniques-force field molecular dynamics simulations, semiempirical GFN2-xTB, and density functional theory calculations-we assess the interaction strength and noncovalent interactions of sunscreen molecules, namely oxybenzone, naphthalene, benzo[a]anthracene, avobenzone, and 1,3,5-trichlorobenzene, with PDMS. Additionally, the effect of temperature on the interaction dynamics is evaluated, with the aim of extending the sorbent capacities of PDMS beyond light polar molecules to larger, polar sunscreen compounds. This study provides critical insights into the molecular-level interactions that may guide the design of novel membrane materials for efficient molecular separation.

Effects of single and combined urinary polycyclic aromatic hydrocarbon effects on lung function in the U.S. adult population

BACKGROUND

The impact of polycyclic aromatic hydrocarbons (PAHs) on lung function has garnered attention, but studies mostly focus on individual effect. This study investigates urinary PAH metabolites as biomarkers of exposure and assesses the relationships between single and combined exposures to nine urinary PAH metabolites and lung function in adults.

METHODS

Data from 4040 adults in the 2007-2012 National Health and Nutrition Examination Survey (NHANES) were analyzed. Weighted generalized linear models estimated the effects of individual PAH metabolites on lung function. Additionally, weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR) were employed to evaluate the combined impacts of multiple PAH metabolites.

RESULTS

Analyses of individual PAH metabolites revealed negative associations with lung function, excluding forced vital capacity (FVC). The WQS, qgcomp, and BKMR models consistently showed that exposure to multiple PAH metabolites was associated with lung function decrease. WQS indicated that 2-hydroxynaphthalene (2-NAP) was the largest contributor to the reductions in forced expiratory volume in 1 s (FEV1), FVC, peak expiratory flow (PEF), and forced expiratory flow from 25 to 75% of FVC (PEF25-75%). Additionally, 1-hydroxypyrene (1-PYR) was the primary PAH metabolite contributing to the decreases in FEV1/FVC and fractional exhaled nitric oxide (FeNO). The combined effect of urinary PAH metabolites did not affect FVC in the current smokers or FeNO in nonsmokers, but decreased FEV1/FVC in current smokers.

CONCLUSION

This study strengthens the negative relationships between multiple PAH metabolites exposure and lung function in adults. Given the limitations of this study, including the lack of knowledge of other exposure pathways and the uncertainty of urinary metabolites, further research is necessary to explore the mechanisms underlying these associations and to address the limitations in exposure assessment.

One-Year Impact of Occupational Exposure to Polycyclic Aromatic Hydrocarbons on Sperm Quality

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) have toxic potential, especially as carcinogens, neurotoxins, and endocrine disruptors. The objective of this study is to know the impact of exposure to PAHs on the reproductive health of male workers who operate in solar thermal plants.

METHODS

Case-control study. A total of 61 men were included: 32 workers exposed to PAH at a solar thermal plant and 29 unexposed people. Seminal quality was studied both at the cellular level (quantity and quality of sperm) and at the biochemical level (magnitudes of oxidative stress in seminal plasma).

RESULTS

In exposure to PAHs, a significantly higher seminal leukocyte infiltration was observed, as well as lower activity in seminal plasma of superoxide dismutase (SOD) and a reduced glutathione/oxidised glutathione (GSH/GSSG) ratio. The oxidative stress parameters of seminal plasma did not show a relationship with sperm cellularity, neither in those exposed nor in those not exposed to PAH.

CONCLUSION

One year of exposure to PAH in a solar thermal plant does not have a negative impact on the sperm cellularity of the worker, either quantitatively (sperm count) or qualitatively (motility, vitality, morphology, or cellular DNA fragmentation). However, PAH exposure is associated with lower antioxidant capacity and higher leukocyte infiltration in seminal plasma.

Plant Defense Mechanisms against Polycyclic Aromatic Hydrocarbon Contamination: Insights into the Role of Extracellular Vesicles

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that pose significant environmental and health risks. These compounds originate from both natural phenomena, such as volcanic activity and wildfires, and anthropogenic sources, including vehicular emissions, industrial processes, and fossil fuel combustion. Their classification as carcinogenic, mutagenic, and teratogenic substances link them to various cancers and health disorders. PAHs are categorized into low-molecular-weight (LMW) and high-molecular-weight (HMW) groups, with HMW PAHs exhibiting greater resistance to degradation and a tendency to accumulate in sediments and biological tissues. Soil serves as a primary reservoir for PAHs, particularly in areas of high emissions, creating substantial risks through ingestion, dermal contact, and inhalation. Coastal and aquatic ecosystems are especially vulnerable due to concentrated human activities, with PAH persistence disrupting microbial communities, inhibiting plant growth, and altering ecosystem functions, potentially leading to biodiversity loss. In plants, PAH contamination manifests as a form of abiotic stress, inducing oxidative stress, cellular damage, and growth inhibition. Plants respond by activating antioxidant defenses and stress-related pathways. A notable aspect of plant defense mechanisms involves plant-derived extracellular vesicles (PDEVs), which are membrane-bound nanoparticles released by plant cells. These PDEVs play a crucial role in enhancing plant resistance to PAHs by facilitating intercellular communication and coordinating defense responses. The interaction between PAHs and PDEVs, while not fully elucidated, suggests a complex interplay of cellular defense mechanisms. PDEVs may contribute to PAH detoxification through pollutant sequestration or by delivering enzymes capable of PAH degradation. Studying PDEVs provides valuable insights into plant stress resilience mechanisms and offers potential new strategies for mitigating PAH-induced stress in plants and ecosystems.

Using bioactive compounds to mitigate the formation of typical chemical contaminants generated during the thermal processing of different food matrices

With rising consumer awareness of health and wellness, the demand for enhanced food safety is rapidly increasing. The generation of chemical contaminants during the thermal processing of food materials, including polycyclic aromatic hydrocarbons, heterocyclic aromatic amines, and acrylamide happens every day in every kitchen all around the world. Unlike extraneous chemical contaminants (e.g., pesticides, herbicides, and chemical fertilizers), these endogenic chemical contaminants occur during the cooking process and cannot be removed before consumption. Therefore, much effort has been invested in searching for ways to reduce such thermally induced chemical contaminants. Recently, the addition of bioactive compounds has been found to be effective and promising. However, no systematic review of this practical science has been made yet. This review aims to summarize the latest applications of bioactive compounds for the control of chemical contaminants during food thermal processing. The underlying generation mechanisms and the toxic effects of these chemical contaminants are discussed in depth to reveal how and why they are suppressed by the addition of certain bioactive ingredients. Examples of specific bioactive compounds, such as phenolic compounds and organic acids, as well as their application scenarios, are outlined. In the end, outlooks and expectations for future development are provided based on a comprehensive summary and reflection of references.

Characterization and risk assessment of polycyclic aromatic hydrocarbons from the emission of different power generator

Epileptic power supply in Sub-Saharan countries of Africa has warranted the use of power generators as an alternative source of power supply. Exhaust emission from these generators is associated with Polycyclic Aromatic Hydrocarbon (PAHs). Hence, this study focused on the determination of levels of PAHs in the emission of different brands of power generators used in Nigeria. Exhaust emissions of different power generators were sampled using a filter-sorbent sampling system with polyurethane foam (PUF) as an adsorbent material. Analysis of PAHs was carried out using a Gas Chromatograph coupled to a mass selective detector (GC- MS) operated on Electron Ionization (EI) mode. The results showed the ∑ PAHs range 14.91-26.0 μ g m - 3 . Bap was the most abundant of all the compounds with a concentration of 2.6 μ g m - 3 with a range of 2.08-3.07 μ g m - 3 . The Incremental Life Cancer Risk (ILCR) values of all the generator's emission sampled are higher than 10- 4 for both children and adult which indicate a high potential cancer risk from inhalation of emission from these generators while Hazard Quotient (HQ) values from all the power generating set in this study are all above 1 which indicated high associated non-carcinogenic. The study revealed the levels of PAHs associated with the emission of power generators in Nigeria.

Association between exposure to polycyclic aromatic hydrocarbons and endometriosis: data from the NHANES 2001-2006

AIM

To evaluate the association between urinary polycyclic aromatic hydrocarbon (PAH) metabolites and the risk of endometriosis.

METHODS

This cross-sectional study obtained data on women aged 20-54 years from the National Health and Nutrition Examination Survey (NHANES) 2001-2006. The weighted multivariate logistic regression model was established to assess the association between the eight urinary PAH metabolites and the risk of endometriosis. In this multivariate analysis, the eight urinary PAH metabolites were adjusted with urinary creatinine, and were divided into three groups according to tertiles: Tertile 1, Tertile 2 and Tertile 3. To evaluate the overall association of mixed PAH metabolites with endometriosis, the Bayesian kernel machine regression (BKMR) model was applied.

RESULTS

Totally 1,291 women were included, of which 90 (6.97%) had endometriosis and 1,201 (93.03%) did not have endometriosis. After adjusting for age, race, smoking, age at menarche, hysterectomy, ovary removed, female hormone use, and menopause, compared with the Tertile 1 group, the Tertile 2 and Tertile 3 groups of all PAH metabolites demonstrated no significant risk of endometriosis. A positive tendency was found between mixed PAH metabolites and endometriosis when all the metabolites were at their 60th percentile levels or above compared with their median levels. When all the other metabolites were fixed at their median levels, 1-hydroxynaphthalene was positively correlated with endometriosis. Potential interactions existed between 1-hydroxynaphthalene and 2-hydroxynaphthalene and between 2-hydroxyfluorene and 3-hydroxyfluorene.

CONCLUSION

No significant association was found between individual PAH metabolites and endometriosis. A positive association existed between mixed PAH metabolites and the risk of endometriosis.

Magnetic solid phase extraction coupled to HPLC-UV for highly sensitive analysis of mono-hydroxy polycyclic aromatic hydrocarbons in urine

BACKGROUND

As a common pollutant, the carcinogenic properties of polycyclic aromatic hydrocarbons have garnered considerable attention. Trace metabolites of polycyclic aromatic hydrocarbons can be detected in urine as a non-invasively approach to monitor the exposure level. Nonetheless, the urine samples have the disadvantages of being large in volume and containing numerous impurities. Given the growing demand to study metabolites with low abundance and potential biomarkers, there is a pressing need for a preconcentration and high-throughput technique for effectively handling complex liquid samples.

RESULTS

Polystyrene-coated magnetic nanoparticles were used to establish a novel magnetic extraction method for monohydroxy polycyclic aromatic hydrocarbons in urine samples. Polystyrene magnetic nanoparticles are an ideal absorbent for solid-phase extraction. After the material was mixed with the sample and adsorbed the target analyte, the analytes on the material were eluted and quantified using high-performance liquid chromatography. Influencing factors were optimized, and the proposed method achieved desirable sensitivity in analyzing low-abundance metabolites in large volumes of complex urine samples. The recoveries of intra-day and inter-day were 78.0-118.0 % and 81.0 %-115.0 %, respectively. The intra-day and inter-day reproducibility were less than 4.5 % and 8.6 %, respectively. The limits of detection were in the range of 0.009-0.041 ng mL-1, and the limits of quantification were in the range of 0.030-0.135 ng mL-1.

SIGNIFICANCE AND NOVELTY

The application of reusable polystyrene-coated magnetic solid-phase nanoparticles as adsorbents makes the extraction of monohydroxy polycyclic aromatic hydrocarbons from urine samples economical and environmentally benign. The proposed method is simple, sensitive, and efficient compared to existing techniques. The nanoparticles are easy to prepare, showing potential for rapid screening of complex bulk bio-samples in batches with high efficiency and low budget.