Contamination and Daily Intake of Polycyclic Aromatic Hydrocarbons in Iranian Bread Samples

Concentration of polycyclic aromatic hydrocarbons (PAHs) in bread and health risk assessment across the globe: A systematic review and meta-analysis

Although bread is the principal food in most countries, polycyclic aromatic hydrocarbons (PAHs) may be present and pose a potential risk to consumers. The aim of this review is to provide a comprehensive report on the concentration and health risks associated with PAHs in bread around the world. Various databases, such as Scopus, PubMed, Science Direct, and Google Scholar, were searched from their beginnings until December 2023 for this systematic review, which included 34 potentially relevant articles with data relating to 1057 bread samples. Utilizing a multilevel regression modeling approach, the study evaluated various factors such as fuel type, bread type, and geographical location. Following the initial evaluation, in 26.47% and 20.28% of all studies, the levels of Bap and PAH4 were higher than the permissible limit values, respectively. Based on the isomer ratios, 55.88% of the studies associated the presence of PAHs in bread samples with pyrogenic/coal combustion sources. According to the carcinogenic risk results, bread consumers in all studies have been exposed to moderate or high levels of carcinogenicity. The most significant risk levels are associated with the consumption of bread in Egypt, Kuwait, Iran, and India. Moreover, meta-regression analysis demonstrated significantly higher toxicity equivalent quotient and cancer risk mean values in bread baked using fossil fuels compared to other sources (p < .05). The high concentrations of PAHs, especially Benzo[a]pyrene, in bread pose a serious public health risk. Stringent regulations and monitoring are crucial to reduce contamination. Further research is necessary to develop safe processing methods to remove PAHs in bread.

Benzo[a]pyrene promotes an epithelial-to-mesenchymal transition process in MCF10A cells and mammary tumor growth and brain metastasis in female mice

Breast cancer is the most frequent neoplasia in developed countries and the leading cause of death in women worldwide. Epithelial-to-mesenchymal transition (EMT) is a cellular process through which epithelial cells decrease or lose their epithelial characteristics and gain mesenchymal properties. EMT mediates tumor progression, because tumor cells acquire the capacity to execute the multiple steps of invasion and metastasis. Benzo[a]pyrene (B[a]P) is an environmental organic pollutant generated during the burning of fossil fuels, wood, and other organic materials. B[a]P exposition increases the incidence of breast cancer, and induces migration and/or invasion in MDA-MB-231 and MCF-7 breast cancer cells. However, the role of B[a]P in the induction of an EMT process and metastasis of mammary carcinoma cells has not been studied in detail. In this study, we demonstrate that B[a]P induces an EMT process in MCF10A mammary non-tumorigenic epithelial cells. In addition, B[a]P promotes the formation of larger tumors in Balb/cJ mice inoculated with 4T1 cells than in untreated mice and treated with dimethyl sulfoxide (DMSO). B[a]P also increases the number of mice with metastasis to brain and the total number of brain metastatic nodules in Balb/cJ mice inoculated with 4T1 cells compared with untreated mice and treated with DMSO. In conclusion, B[a]P induces an EMT process in MCF10A cells and the growth of mammary tumors and metastasis to brain in Balb/cJ mice inoculated with 4T1 cells.

The carcinogenic PAHs in breads, amount, analytical method and mitigation strategy, a systematic review study

Bread is one of the most consumed foods all over the world. Several contaminants are identified in bread. Polycyclic aromatic hydrocarbons (PAHs) is one of these contaminants. This systematic study evaluates the amount of four carcinogenic PAHs (PAH4) in various types of breads. To conduct this study, a comprehensive search was carried out using keywords of polycyclic aromatic hydrocarbons, PAHs, PAH4, and bread, with no time limitations. 17 articles were selected and fully evaluated. The observed range of PAH4 concentrations in bread varied from non-detected (ND) to 20.66 µg/kg. In the sample preparation process for analysis, an ultrasonic bath was predominantly utilized. Most chromatographic methods are able to measure PAHs in food, but the GC-MS method has been used more. To mitigate PAH levels in bread, it is suggested to incorporate antioxidants during the bread-making process. Furthermore, the type of bread, the type of fuel used to bake the bread, the temperature and the cooking time were some of the factors affecting the amount of PAH. Restricting these factors could significantly reduce PAH content. Regarding the risk assessment conducted in the manuscript, it was determined that industrial breads are usually considered safe. However, some traditional breads may pose risks in terms of their potential PAH content.

Benzo[a]pyrene-Environmental Occurrence, Human Exposure, and Mechanisms of Toxicity

Benzo[a]pyrene (B[a]P) is the main representative of polycyclic aromatic hydrocarbons (PAHs), and has been repeatedly found in the air, surface water, soil, and sediments. It is present in cigarette smoke as well as in food products, especially when smoked and grilled. Human exposure to B[a]P is therefore common. Research shows growing evidence concerning toxic effects induced by this substance. This xenobiotic is metabolized by cytochrome P450 (CYP P450) to carcinogenic metabolite: 7β,8α-dihydroxy-9α,10α-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), which creates DNA adducts, causing mutations and malignant transformations. Moreover, B[a]P is epigenotoxic, neurotoxic, and teratogenic, and exhibits pro-oxidative potential and causes impairment of animals' fertility. CYP P450 is strongly involved in B[a]P metabolism, and it is simultaneously expressed as a result of the association of B[a]P with aromatic hydrocarbon receptor (AhR), playing an essential role in the cancerogenic potential of various xenobiotics. In turn, polymorphism of CYP P450 genes determines the sensitivity of the organism to B[a]P. It was also observed that B[a]P facilitates the multiplication of viruses, which may be an additional problem with the widespread COVID-19 pandemic. Based on publications mainly from 2017 to 2022, this paper presents the occurrence of B[a]P in various environmental compartments and human surroundings, shows the exposure of humans to this substance, and describes the mechanisms of its toxicity.

The analysis and probabilistic health risk assessment of polycyclic aromatic hydrocarbons in cereal products

The analysis and probabilistic health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in cereal products were done by using magnetic solid-phase extraction (MSPE) method and gas chromatography/mass spectrometric (GC/MS). The results of method showed LOQ and LOD of PAHs compounds were 0.105-0.180 and 0.035-0.060 µg/kg, and the recorded values were 4.3-12.1 and 6.1-20.3% for repeatability and reproducibility with an estimated recovery of 94.4-103.4%. In this study, we analyzed kind of bread (Barbari, Sangak, Baguette, Taftoon, Lavash), macaroni, lasagna, and cooked rice that mean of total PAHs were 98.2, 121.7, 134.9, 166.3, 176.3, 176.2, 130.1, and 248.3 μg/kg, respectively. Further, the correlation between the type and amount of 16 PAHs with cereal products samples evaluated with multivariate principal component analysis and heat map visualization. The highest incremental lifetime cancer risk (ILCR) was found in cooked rice (7.80E-6), while the lowest ILCR was found in Lasagna (2.35E-07). In conclusion, the PAHs content in the tested products were in low health risk ranges (1 × 10^-6 < ILCR < 1 × 10^-4), and all of the cereal products sold in Tehran are considered safe for consumers. Therefore, cereal products should be regularly evaluated and monitored by regulatory agencies to reduce contaminants in these high-consumption products.

Polycyclic Aromatic Hydrocarbons in Foods: Biological Effects, Legislation, Occurrence, Analytical Methods, and Strategies to Reduce Their Formation

Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds comprised of carbon and hydrogen molecules in a cyclic arrangement. PAHs are associated with risks to human health, especially carcinogenesis. One form of exposure to these compounds is through ingestion of contaminated food, which can occur during preparation and processing involving high temperatures (e.g., grilling, smoking, toasting, roasting, and frying) as well as through PAHs present in the soil, air, and water (i.e., environmental pollution). Differently from changes caused by microbiological characteristics and lipid oxidation, consumers cannot sensorially perceive PAH contamination in food products, thereby hindering their ability to reject these foods. Herein, the occurrence and biological effects of PAHs were comprehensively explored, as well as analytical methods to monitor their levels, legislations, and strategies to reduce their generation in food products. This review updates the current knowledge and addresses recent regulation changes concerning the widespread PAHs contamination in several types of food, often surpassing the concentration limits deemed acceptable by current legislations. Therefore, effective measures involving different food processing strategies are needed to prevent and reduce PAHs contamination, thereby decreasing human exposure and detrimental health effects. Furthermore, gaps in literature have been addressed to provide a basis for future studies.