Evaluation of benzo[a]pyrene in food from China by high-performance liquid chromatography-fluorescence detection

Mechanism of action of anthocyanin on the detoxification of foodborne contaminants-A review of recent literature

Foodborne contaminants refer to substances that are present in food and threaten food safety. Due to the progress in detection technology and the rising concerns regarding public health, there has been a surge in research focusing on the dangers posed by foodborne contaminants. These studies aim to explore and implement strategies that are both safe and efficient in mitigating the associated risks. Anthocyanins, a class of flavonoids, are abundantly present in various plant species, such as blueberries, grapes, purple sweet potatoes, cherries, mulberries, and others. Numerous epidemiological and nutritional intervention studies have provided evidence indicating that the consumption of anthocyanins through dietary intake offers a range of protective effects against the detrimental impact of foodborne contaminants. The present study aims to differentiate between two distinct subclasses of foodborne contaminants: those that are generated during the processing of food and those that originate from the surrounding environment. Furthermore, the impact of anthocyanins on foodborne contaminants was also summarized based on a review of articles published within the last 10 years. However, further investigation is warranted regarding the mechanism by which anthocyanins target foodborne contaminants, as well as the potential impact of individual variations in response. Additionally, it is important to note that there is currently a dearth of clinical research examining the efficacy of anthocyanins as an intervention for mitigating the effects of foodborne pollutants. Thus, by exploring the detoxification effect and mechanism of anthocyanins on foodborne pollutants, this review thereby provides evidence, supporting the utilization of anthocyanin-rich diets as a means to mitigate the detrimental effects of foodborne contaminants.

Low-dose benzo[a]pyrene exposure induces hepatic lipid deposition through LCMT1/PP2Ac-mediated autophagy inhibition

Non-alcoholic fatty liver disease (NAFLD) is a progressive disorder of liver metabolism and has become the most common chronic liver disease worldwide. Benzo[a]pyrene (BaP) is recognized as a potent carcinogen, but the effect of low-dose BaP on the development of NAFLD has not been well-studied, and its molecular mechanism is still unknown. In this study, we demonstrated that low-dose BaP induced hepatic steatosis in a mouse model with a notable increase in hepatic lipid content. Interestingly, mRNA expression of genes related to fatty acids uptake or synthesis was not significantly altered after BaP exposure. Instead, we found that low-dose BaP promoted lipid deposition in primary mouse hepatocytes by inhibiting autophagy, which was regulated through Leucine carboxyl methyltransferase-1 (LCMT1) mediated Protein Phosphatases 2A subunit C (PP2Ac) methylation. The role of LCMT1 in BaP-induced steatosis was further validated in a liver-specific lcmt1 knockout (L-LCMT1 KO) mouse model. In this study, we provided evidence to support a novel mechanism by which BaP induces the development of hepatic steatosis through PP2Ac mediated autophagy inhibition. These findings provided new insight into the pathogenesis of NAFLD induced by environmental exposure to low-dose BaP.

Polycyclic aromatic hydrocarbons (PAHs) in meat, poultry, fish and related product samples of Iran: a risk assessment study

Meat, poultry, and seafood such as fish are a valuable source of protein, vitamins and minerals. Considering their high consumption in the human diet, it is necessary to study pollutants (such as PAHs) in them. This present study has focused on the PAHs level and probabilistic risk of health in meat, poultry, fish and related product samples by MSPE-GC/MS technique (magnetic solid-phase extraction with gas chromatography-mass spectrometry). The maximum mean of 16 PAH was detected in smoked fish samples (222.7 ± 13.2 μg/kg) and the minimum mean of 16 PAH was detected in chicken (juje) kebab (112.9 ± 7.2 µg/kg μg/kg). The maximum mean of 4PAHs was detected in tuna fish (23.7 ± 2.4 µg/kg) and the minimum mean of 4PAHs was seen in grilled chicken and sausage samples (non-detected). Our results showed the 4PAHs and B[a]P were lower than the EU (European Union) standard levels (these standard levels were 30 and 5 μg/kg, respectively). Furthermore, the correlation among the type and concentrations of PAHs congeners was investigated through cluster analysis by heat map and principal component analysis. The 90th percentile ILCR (incremental lifetime cancer risk) of PAH compounds in fish, poultry, meat and related products samples was 3.39E-06, which was lower than the maximum acceptable level of risk (10-4). Finally, the highest ILCR was related to hamburger (4.45E-06). Therefore, there is no risk in consuming these foods in Iran, but it is necessary to monitor PAHs concentration in different types of foods.

A surface-enhanced Raman scattering sensor for the detection of benzo[a]pyrene in foods based on a gold nanostars@reduced graphene oxide substrate

In this study, a simple and sensitive surface-enhanced Raman scattering (SERS) sensor based on gold nanostars@reduced graphene oxide (AuNS@rGO) was successfully developed for the detection of benzo[a]pyrene in foods. The detection strategy involved benzo[a]pyrene adsorption on reduced graphene oxide, followed SERS detection of adsorbed molecules. Owing to the large electric fields generated by the gold nanostars under laser irradiation, which greatly amplified the Raman signals of benzo[a]pyrene, very high sensitivity for the target analyte was achieved. Under optimized conditions, the SERS sensor exhibited a wide linear detection range for benzo[a]pyrene (from 0.1 μg L^-1 to 10000 μg L^-1), with a low limit of detection of 0.0028 μg L^-1. Chicken samples spiked with benzo[a]pyrene were assayed using the sensor, with recoveries ranging from 89.20% to 100.80%. The benzo[a]pyrene content in roasted mutton sample was quantified using the SERS sensor and a reversed-phase high-performance liquid chromatography method, with similar results being obtained.

Benzo[a]pyrene induces epithelial tight junction disruption and apoptosis via inhibiting the initiation of autophagy in intestinal porcine epithelial cells

Ingestion of food contaminated with benzo[a]pyrene (B[a]P) poses health risks to animals and humans. However, the toxicity of B[a]P exposure on the intestinal barrier function and underlying mechanisms remain obscure. In the present study, intestinal porcine epithelial cells (IPEC-1) were challenged with different doses of B[a]P and its deleterious effects were determined. We found that B[a]P exposure led to impaired intestinal tight junction function as evidenced by reduced transepithelial electric resistance, increased permeability, and downregulated intestinal tight junction protein levels. Further study demonstrated that B[a]P treatment induced cell cycle arrest, and resulted in oxidative damage-related apoptosis in IPEC-1 cells. Intriguingly, we observed an inhibition of autophagy and an activation of unfolded protein response (UPR) in B[a]P-challenged cells, when compared with controls. To investigate the role of autophagy on B[a]P-induced epithelial tight junction disruption and apoptosis, cells were cotreated with B[a]P and rapamycin, and rapamycin dramatically improved intestinal tight junction and reduced apoptosis, indicating a protective effect of autophagy for the cells in response to B[a]P treatment. We also explored the role of UPR in B[a]P-induced cellular damage by using 4-phenylbutyric acid, an antagonist of UPR. Interestingly, B[a]P-induced apoptosis and dysfunction of the intestinal tight junction were exacerbated by 4-phenylbutyric acid, and the 4-phenylbutyric acid didn't ameliorate the inhibitory effects of B[a]P on microtubule-associated protein 1 light chain 3 (LC3-II) and lysosomal-associated membrane protein 2 (LAMP2) in IPEC-1 cells. These novel findings provided herein indicated that B[a]P induces intestinal epithelial tight junction disruption and apoptotic cell death via inhibiting autophagy in IPEC-1 cells.

A transcriptome-wide association study of uterine fibroids to identify potential genetic markers and toxic chemicals

Uterine fibroid is one of the most prevalent benign tumors in women, with high socioeconomic costs. Although genome-wide association studies (GWAS) have identified several loci associated with uterine fibroid risks, they could not successfully interpret the biological effects of genomic variants at the gene expression levels. To prioritize uterine fibroid susceptibility genes that are biologically interpretable, we conducted a transcriptome-wide association study (TWAS) by integrating GWAS data of uterine fibroid and expression quantitative loci data. We identified nine significant TWAS genes including two novel genes, RP11-282O18.3 and KBTBD7, which may be causal genes for uterine fibroid. We conducted functional enrichment network analyses using the TWAS results to investigate the biological pathways in which the overall TWAS genes were involved. The results demonstrated the immune system process to be a key pathway in uterine fibroid pathogenesis. Finally, we carried out chemical–gene interaction analyses using the TWAS results and the comparative toxicogenomics database to determine the potential risk chemicals for uterine fibroid. We identified five toxic chemicals that were significantly associated with uterine fibroid TWAS genes, suggesting that they may be implicated in the pathogenesis of uterine fibroid. In this study, we performed an integrative analysis covering the broad application of bioinformatics approaches. Our study may provide a deeper understanding of uterine fibroid etiologies and informative notifications about potential risk chemicals for uterine fibroid.

Construction of novel magnetic nanoparticles for enrichment of benzo(α)pyrene from edible oils followed by HPLC determination

A novel method for benzo(α)pyrene (Bαp) enrichment from an oil matrix was developed by using magnetic nanoparticles (Fe₃O₄@dopamine/graphene oxide, Fe₃O₄@DA/GO) as extraction absorbents, and the chemical properties of the synthesized nanoparticles were characterized. Various parameters were investigated to optimize the extraction of Bαp from oils. Under optimal conditions (pH, 4; extraction time, 0.5 min; elution solvent, 1 mL; absorbent weight, 20 mg; elution time, 0.5 min), these nanoparticles showed excellent abilities to enrich Bαp from the saponified oil solution and were easily separated by a magnet. High-performance liquid chromatography plus fluorescence detection (HPLC-FLD) was then applied to determine the Bαp content with excellent linearity (R² = 0.999). The detection limit was 0.13 µg/kg, while the limit of quantification was 0.42 µg/kg. The spiked recoveries of Bαp in oils ranged from 73.5% to 121%. Compared with previous reports, the proposed method displayed many advantages, including a high efficiency of oil matrix removal, short extraction time, and convenient extraction procedure.

Sporoderm-broken spores of Ganoderma lucidum alleviates liver injury induced by DBP and BaP co-exposure in rat

Dibutyl phthalate (DBP) and Benzo(a)pyrene (BaP) are ubiquitous contaminants in environment and foodstuffs, which increase the chance of their combined exposure to humans in daily life. However, the combined effects of DBP and BaP on liver and the underlying mechanisms are still unclear. In this study, we explored the combined effects of DBP and BaP on liver and the potential mechanisms in a rat model. We found that DBP and BaP co-exposure activated the MyD88/NF-κB pathway through increasing TLR4 acetylation (TLR4ac) level, leading to the imbalance of pro-inflammatory factors (CXCL-13, IL-6 and TNF-α) and anti-inflammatory factors (IL-10), ultimately resulting in liver tissue damage and functional changes. Sporoderm-broken spores of Ganoderma lucidum (SSGL) had strong alleviating effects on liver injury induced by DBP and BaP co-exposure. Our study found that SSGL suppressed TLR4ac-regulated MyD88/NF-κB signaling to reduce the release of pro-inflammatory factors, and promote the secretion of IL-10, thus alleviating liver injury caused by DBP and BaP co-exposure. In conclusion, SSGL contributed to liver protection against DBP and BaP-induced liver injury in rats via suppressing the TLR4ac-regulated MyD88/NF-κB signaling.

Impact of benzo[a]pyrene with other pollutants induce the molecular alternation in the biological system: Existence, detection, and remediation methods

The exposure of benzo [a]pyrene (BaP) in recent times is rather unavoidable than ever before. BaP emissions are sourced majorly from anthropogenic rather than natural provenance from wildfires and volcanic eruptions. A major under-looked source is via the consumption of foods that are deep-fried, grilled, and charcoal smoked foods (meats in particular). BaP being a component of poly aromatic hydrocarbons has been classified as a Group I carcinogenic agent, which has been shown to cause both systemic and localized effects in animal models as well as in humans; has been known to cause various forms of cancer, accelerate neurological disorders, invoke DNA and cellular damage due to the generation of reactive oxygen species and involve in multi-generational phenotypic and genotypic defects. BaP's short and accumulated exposure has been shown in disrupting the fertility of gamete cells. In this review, we have discussed an in-depth and capacious run-through of the various origins of BaP, its economic distribution and its impact as well as toxicological effects on the environment and human health. It also deals with a mechanism as a single compound and its ability to synergize with other chemicals/materials, novel sensitive detection methods, and remediation approaches held in the environment.

The Effect of Combined Superheated Steam Roasting and Smoking on the Quality Characteristic of Alaska Pollack (Gadus chalcogrammus) Roe

Alaska pollack roe (APR) is a protein source that is usually salted and fermented, containing a high salt content. Using a combination of superheated steam roasting and smoking, we developed a new low-salt ready-to-eat APR variant, whose quality characteristics we analyzed. The optimal conditions for roasting (216 °C for 4 min) and smoking (64 °C for 14 min) were obtained from sensorial attributes using response surface methodology. Under the optimal conditions, smoke-roasted APR had an overall acceptance (OA) score of 8.89. The combination of roasting and smoking significantly increased volatile basic nitrogen (VBN, 18.6%) and decreased the total bacterial count (TBC, 38.6%), while thiobarbituric acid reactive substances (TBARS) were not affected. Smoke-roasting APR also increased its nutritional content to 30% protein with 44% essential amino acids, and more than 40% DHA and EPA in 4.3% fat. During 30 days of storage, the OA, VBN, TBARS, and TBC values significantly changed with time and storage temperature (p < 0.05). The shelf life of the product was estimated to be 24 d. In conclusion, the combination of roasting and smoking APR could improve product quality and may be an alternative to diversify processed APR.

Polycyclic aromatic hydrocarbons in grilled foods from Kermanshah province

Grilling is one of the most traditional ways of cooking foods, especially meat, which can produce a number of carcinogenic compounds. This study was to identify the pattern of kebab consumption and its PAHs among a selection of the Iranian population. Kebab consumption pattern were assessed using a validated questionnaire. A sample of three types of popular kebabs, including Koobideh (minced meat), Barg (crushed meat pieces), and Juje (chopped chicken pieces), was collected from each restaurant and then transferred to a laboratory to measure PAHs. The median benzo[a]pyrene concentrations (7.85 μg/kg) and the sum of benzo[a]pyrene, chrysene, benzo[a]anthracene, and benzo[b]fluoranthene concentrations (15.74 μg/kg) were higher than the maximum level imposed by the Commission of the European Communities. A significant relationship between Barg kebab prepared with charcoal and the amounts of anthracene, benzo[a]anthracene, dibenzo[a,h]pyrene, and benzo[g,h,i]perylene was found. The highest PAHs produced in samples prepared with charcoal was dibenzo[a,h]pyrene.

Assessment of 9-OH- and 7,8-diol-benzo[a]pyrene in Blood as Potent Markers of Cognitive Impairment Related to benzo[a]pyrene Exposure: An Animal Model Study

The potent neurotoxicity of benzo[a]pyrene (B[a]P) has been suggested to be a susceptibility factor accelerating the onset of brain tumours and the emergence of neurobehavioural disturbances. B[a]P has been shown to be neurotoxic, acting directly on both the central and peripheral nervous systems, as well as indirectly via peripheral organs like liver and gut. By using a realistic B[a]P exposure scenario (0.02-200 mg/kg/day, 10 days) in mice, we elucidated brain-specific B[a]P metabolism and at identified hydroxylated B[a]P metabolites in serum which could be used as markers of cognitive impairment. Repeated oral administration of B[a]P led to, at the doses of 20 and 200 mg/kg/day, significant overexpression of Cyp1a1/Cyp1b1 in 2 out of the 3 brain regions considered, thereby suggesting the ability of the brain to metabolize B[a]P itself. At the same doses, mice exhibited a reduction in anxiety in both the elevated plus maze and the hole board apparatus. Concomitantly, B[a]P triggered dose-dependent changes in Nmda subunit expression (Nr1 and Nr2a/Nr2b) in areas involved in cognition. We detected 9-OH-B[a]P and 7,8-diol-B[a]P in serum at the level for which cognitive impairment was observed. We suggest that these metabolites may, in the future be exploited as potent biomarkers of B[a]P-induced cognitive impairments.

Effects of Different Smoking Materials and Methods on the Quality of Chinese Traditional Bacon (Larou)

ABSTRACT

Larou is a traditional smoked meat product in China. In this experiment, larou was processed with different smoking materials and methods to determine whether differences in processing methods would affect the quality of the larou and the concentrations of carcinogens. Pork bellies were marinated, dried, and divided into four groups and then directly smoked with four different smoking materials for 40 min. The smoking material for larou that was most effective was then used with an indirect smoking device with an nano-activated carbon fiber filter and evaluated as a single-factor variable. The surface area of the nano-activated carbon filter was 978.00 m2/g, and this filter effectively adsorbed the ash particles from the smoke. For the group smoked with pomelo skins (PS), the highest concentrations and number of phenols were 4.48% and 11, respectively, which increased the smoke flavor significantly. The moisture was 32.64%, and the Staphylococcus, lactic acid bacteria, and yeast and mold levels were 0.98, 1.10, and 0.59 log CFU/g, indicating inhibition of harmful bacteria and a beneficial microbial environment for larou fermentation. The benzo[a]pyrene (B[a]P) concentration in PS smoke determined with the indirect smoking device was 1.82 μg/kg, whereas that determined with the direct smoking device was 36.1 μg/kg, a significant difference (P < 0.01). These findings suggested that indirect smoking with PS could effectively maintain microbial quality and reduce the B[a]P[mc] concentrations in larou. This processing method can be used for the production of this meat product.

HIGHLIGHTS

Protective effect of hawthorn extract against genotoxicity induced by benzo(<alpha>)pyrene in C57BL/6 mice

Benzo(<alpha>)pyrene [B(<alpha>)P], widely originated from environmental pollution or food process such as roasting and frying, is a strong mutagen and potent carcinogen. Utilization of hawthorn has been reported against physical mutagens. Our study found that hawthorn extract (HE) contained abundant phenolic compounds, wherein chlorogenic acid was 2.78 mg/g, procyanidine B2 was 3.58 mg/g, epicatechin was 2.99 mg/g DW, which may contribute to anti-genotoxicity activity. So, the role of HE against B(<alpha>)P-induced genotoxicity in C57BL/6 mice was further assessed. Fifty mice were distributed into five groups: control group, B(<alpha>)P group (30 mg/kg, i.p.), B(<alpha>)P + HE-L group (100 mg/kg, i.g.), B(<alpha>)P + HE-M group (200 mg/kg, i.g.), B(<alpha>)P + HE-H group (400 mg/kg, i.g.). Mice were orally administered with solutions of HE for 10 days and injected intraperitoneally with B(<alpha>)P for 3 days from the 8th day. Results showed that B(<alpha>)P can induce significantly pathological damage in liver, lung and spleen, as well as decrease white blood cells (WBCs). Remarkably elevated levels of reactive oxygen species (ROS), DNA strand breaks (DSBs) and G1 cell cycle arrest were also found in B(<alpha>)P group, with upregulated expressions of p-H2AX, p-p53 and p21 in bone marrow cells. With administration of HE, liver, lung and spleen injury significantly mitigated, while WBCs were evidently increased in B(<alpha>)P-treated mice. Consistently, HE markedly reduced level of ROS, DSBs and G1 cell cycle arrest accompanied by reducing expressions of p-H2AX, p-p53 and p21 in bone marrow cells. Combined, these results indicated a protective role of HE on B(<alpha>)P-induced genotoxicity.

The intervention mechanism of folic acid for benzo(a)pyrene toxic effects in vitro and in vivo

Folic acid is a necessary micronutrient for normal human growth and development. Benzo(a)pyrene (BaP) is a ubiquitously distributed environmental pollutant and its metabolite, benzo(a)pyrene-diol-epoxide, is known to exert a strong teratogenic and carcinogenic effect on the body’s tissues and cells. The aim of this study was to investigate the mechanism by which folic acid can inhibit the toxic effects of BaP both in vivo and in vitro. We measured changes in 16HBE cell activity affected by the intervention of folic acid on BaP using the cell counting kit-8 assay and that of cell cycle distribution by flow cytometry. At the same time, we assessed the xeroderma pigmentosum group A, xeroderma pigmentosum group C, excision repair cross complementation group 1, cyclinD1, and CKD4 mRNAs, and their related protein expression both in mouse lung tissue and in 16HBE cells. In conclusion, the mechanisms by which this effect is mediated were not entirely elucidated by our study, possibly because folic acid antagonizes the toxic effects of BaP by upregulating the levels of excision repair cross complementation group 1, xeroderma pigmentosum group A, and xeroderma pigmentosum group C gene expression to improve the rate of DNA repair, in turn accelerating the speed of repair for DNA damage caused by BaP. Meanwhile, folic acid could restrain BaP-induced cyclinD1 protein expression, which could help cells return to their normal cell cycle.

Influence of E-beam irradiation on microbiological and physicochemical properties and fatty acid profile of frozen duck meat

This study investigated the effect of different doses (0, 3, and 7 kGy) of e-beam on the microbiological and physicochemical qualities and the profile of fatty acids of the frozen duck meat (FDM). Electron beam at the dose of 3 kGy showed more than 2 log and 1 log cycles of reduction in the total bacterial (TAB) and coliform counts (TCC), respectively. The results indicated an increase in the TBARS values (1.50 ± 0.02 mg MDA/kg), peroxide value (0.83 ± 0.04 meq peroxide/kg), and total volatile base nitrogen (1.31 ± 0.16 mg/100 ml), but no effect on the sensory parameters. Irradiation lowered the lightness (L*) (31.87 ± 0.98) and redness (a*) (11.04 ± 0.20) values but elevated the metmyoglobin content in FDM. In addition, irradiation had no effect on the benzopyrene content; however, a reduction was observed in the vitamin A (0.239 ± 0.015 µg/g) and vitamin E (1.847 ± 0.075 µg/g) contents of the FDM samples. There were no trans-fatty acids present in the treated (irradiated) as well as the untreated (nonirradiated) meat samples (FDM), whereas the fatty acid content decreased in irradiated samples, in contrast with the nonirradiated control. Electronic nose clearly discriminated between the nonirradiated and irradiated FDM based on principal component analysis. It is concluded that the e-beam successfully improved the microbial quality of FDM with slight changes in physicochemical properties, but without altering its sensory properties.

Determination of benzo[a]pyrene in camellia oil via vortex-assisted extraction using the UPLC-FLD method

In this paper, vortex-assisted extraction using the ultraperformance liquid chromatography analysis method was performed to determine benzo[a]pyrene in camellia oil. Optimum results were obtained when 0.5 g of oil sample was used followed by vortex-assisted extraction for 10 min with 25 mL of acetonitrile. Chromatographic separation was performed on an Agilent ZORBAX Eclipse Plus C₁₈ column (2.1mm×100mm, particle size 1.8 μm). The optimum mobile phase comprised 70% acetone and 30% water. The detection limit of benzo[a]pyrene was 0.2 μg/kg. The recoveries were in the range of 81.0-97.0%. The proposed method was simple and fast, and it provided high throughput in the determination of benzo[a]pyrene in an oil matrix sample.

Effects of cooking methods and tea marinades on the formation of benzo[a]pyrene in grilled pork belly (Samgyeopsal)

We investigated the effects of different grilling tools, temperatures, and tea marinades on the formation of benzo[a]pyrene in grilled pork belly as well as the antioxidant capacities of tea marinades. The least amount of benzo[a]pyrene was detected in modified charcoal-grilled pork belly (1.28μg/kg). The highest risk factors for the formation of benzo[a]pyrene are direct contact with flames and fat excess on the heating source. A modified charcoal grill can be used as an alternative grilling tool to meet consumer needs for safety and taste. The marination of pork bellies with tea increased radical-scavenging activity and prevented lipid oxidation in proportion to the concentration of tea infusion and marinating time. The yerba mate tea marinade significantly increased the radical-scavenging activity and prevented benzo[a]pyrene formation more than the green tea marinade. Tea marinade can be applied to seasoning or sauce as pretreatment to preserve the quality of meat and to decrease benzo[a]pyrene formation during cooking.

Red Meat and Health

Despite its nutritional benefits, there is an increasing body of evidence to suggest that regular consumption of red meat may negatively impact health and disease risk, including the risk of most common chronic diseases. This chapter reviews the current evidence linking red and processed meat intakes with chronic disease, obesity and mortality risks and discusses possible mechanisms to explain these associations. Research on the health benefits of diets low in red meat, including vegetarian, vegan, Mediterranean and other plant-based diets, is also reviewed.

Predicting lung dosimetry of inhaled particleborne benzo[a]pyrene using physiologically based pharmacokinetic modeling

Benzo[a]pyrene (BaP) is a by-product of incomplete combustion of fossil fuels and plant/wood products, including tobacco. A physiologically based pharmacokinetic (PBPK) model for BaP for the rat was extended to simulate inhalation exposures to BaP in rats and humans including particle deposition and dissolution of absorbed BaP and renal elimination of 3-hydroxy benzo[a]pyrene (3-OH BaP) in humans. The clearance of particle-associated BaP from lung based on existing data in rats and dogs suggest that the process is bi-phasic. An initial rapid clearance was represented by BaP released from particles followed by a slower first-order clearance that follows particle kinetics. Parameter values for BaP-particle dissociation were estimated using inhalation data from isolated/ventilated/perfused rat lungs and optimized in the extended inhalation model using available rat data. Simulations of acute inhalation exposures in rats identified specific data needs including systemic elimination of BaP metabolites, diffusion-limited transfer rates of BaP from lung tissue to blood and the quantitative role of macrophage-mediated and ciliated clearance mechanisms. The updated BaP model provides very good prediction of the urinary 3-OH BaP concentrations and the relative difference between measured 3-OH BaP in nonsmokers versus smokers. This PBPK model for inhaled BaP is a preliminary tool for quantifying lung BaP dosimetry in rat and humans and was used to prioritize data needs that would provide significant model refinement and robust internal dosimetry capabilities.

Red Meat and Health

Despite its nutritional benefits, there is an increasing body of evidence to suggest that regular consumption of red meat may negatively impact health and disease risk, including the risk of most common chronic diseases. This chapter reviews the current evidence linking red and processed meat intakes with chronic disease, obesity and mortality risks and discusses possible mechanisms to explain these associations. Research on the health benefits of diets low in red meat, including vegetarian, vegan, Mediterranean and other plant-based diets, is also reviewed.