Presence Of Benzo Research Articles

Polycyclic aromatic hydrocarbons in permafrost peatlands

The concentrations of 15 individual PAHs in 93 peat cores have been determined by using high-performance liquid chromatography methods. In the profile the qualitative and quantitative composition of PAHs was non-uniform estimated in a wide range: from 112 to 3673 ng/g with mean 1214 ± 794 ng/g. Among 15 identified individual PAHs, the main contribution to their total amount was made by heavy highly condensed PAHs in the Eastern European peat plateaus, in particular, 6-nuclear benzo[ghi]perylene (1021 ± 707 ng/g), whereas in West Siberian permafrost peatlands, light PAHs were dominating, mostly naphthalene and phenanthrene (211 ± 87 and 64 ± 25 ng/g, respectively). The grass-equisetum peat contained the maximum of heavy PAHs and the dwarf shrub-grass—the minimum. In grass-dwarf shrub, grass-moss and moss peat, the share of 2-nuclear PAHs was most significant: naphthalene and fluorene, as well as 6-nuclear benzo[ghi]perylene. The presence of benzo[ghi]perylene in the entire peat strata, including its permafrost layer, was a marker of the anaerobic conditions that persisted throughout the Holocene and they were necessary for the synthesis of this compound.

Insilico Insight into the Association between Polycyclic Aromatic Hydrocarbons and Human Toll like Receptor in Progression of Esophageal Carcinogenesis

Cancer creates enormous burden and is a leading cause of death in most of the countries. Esophageal cancer (EC) is one of the most common cancers in the world and has the worst survival of all cancers. Esophageal Squamous Cell Carcinoma (ESCC) and adenocarcinoma are the two main types of esophageal cancer. Exposure of polycyclic aromatic hydrocarbons (PAHs) can be cited as one of the reasons for development of Esophageal Squamous Cell Carcinoma. Toll Like Receptors (TLRs) present in human esophageal epithelial cells may pose a major role in pathogen recognition, activation of innate immunity and cancer. The study attempts to predict the role of carcinogenic PAHs in TLR4 signaling pathway and how it can ultimately result in immuno suppression and development of esophageal cancer by insilico docking evaluation. For the study we retrieved the structure of sixteen PAHs from the PubChem database and the protein model of TLR4 (PDB ID: 4G8A) from protein data bank (PDB). The binding affinity of PAHs to the TLR4 receptor was calculated using molecular docking software Auto Dock1.5. The results showed that Benzo[a]pyrene showed strong interaction toward TLR4 receptor with the highest number of polar contacts along with high binding affinity values. Considering the presence of Benzo[a] pyrene in different environmental, occupational and behavioral sources globally, there is a need for future research on the risk assessment of Benzo[a]pyrene on Esophageal Squamous Cell Carcinoma.

Bioaugmentation strategy to enhance polycyclic aromatic hydrocarbons anaerobic biodegradation in contaminated soils

This paper proposes an innovative bioaugmentation approach for the remediation of polycyclic aromatic hydrocarbon (PAH) contaminated soils, based on a novel habitat-based strategy. This approach was tested using two inocula (i-24 and i-96) previously enriched through an anaerobic digestion process on wheat straw. It relies on the application of allochthonous microorganisms characterized by specific functional roles obtained by mimicking a natural hydrolytic environment such as the rumen. The inocula efficiency was tested in presence of naphthalene alone, benzo[a]pyrene alone, and a mix of both of them. In single-contamination tests, i-24 inoculum showed the highest biodegradation rates (84.7% for naphthalene and 51.7% for benzo[a]pyrene). These values were almost 1.2 times higher than those obtained for both contaminants with i-96 inoculum and in the control test in presence of naphthalene alone, while they were 3 times higher compared to the control test in presence of benzo[a]pyrene alone. In mixed-contamination tests, i-96 inoculum showed final biodegradation efficiencies for naphthalene and benzo[a]pyrene between 1.1 and 1.5 higher than i-24 inoculum or autochthonous biomass. Total microbial abundances increased in the bioaugmented tests in line with the PAH degradation. The microbial community structure showed the highest diversity at the end of the experiment in almost all cases. Values of the Firmicutes active fraction up to 7 times lower were observed in the i-24 bioaugmented tests compared to i-96 and control tests. This study highlights a successful bioaugmentation strategy with biological components that can be reused in multiple processes supporting an integrated and environmentally sustainable bioremediation system.

Polycyclic Aromatic Hydrocarbons (PAH) in Atmospheric Particles (PM2.5 and PM2.5–10): Integrated Evaluation of the Environmental Scenario in Urban Areas

The 16 United States Environmental Protection Agency (US EPA) priority polycyclic aromatic hydrocarbons (PAHs) are considered carcinogenic and mutagenic for humans and are emitted by anthropogenic sources mainly in urban areas. For this purpose, the carcinogenic risk in the Metropolitan Region of Porto Alegre/RS (RMPA), Brazil, was investigated due to its demographic density (421.8 inhabitants/km2), industrialization, and high flow of vehicles. The concentration of the 16 PAHs present in PM10–2.5 and PM2.5 was evaluated, and so their origins, the carcinogenic risk of inhalation, and their interaction with meteorological parameters. Dichotomous sampler was used to collect the PM10–2.5 and PM2.5 in the cities of Canoas (CA) and Novo Hamburgo (NH) in RMPA for having different industries and demographic densities. Extracts containing PAHs were analyzed by gas chromatography coupled to mass spectrometry to determine the concentration of PAHs. Thirteen PAHs were found, mainly in PM2.5. The carcinogenic risk was above the US EPA recommended safety range (1 × 10−6) in PM2.5 and PM2.5–10 at both NH and CA. Naphthalene obtained the highest concentration, but the presence of benzo[a]pyrene was determinant for the higher carcinogenic risk in PM2.5. PAHs in RMPA are emitted mainly from burning by vehicles, increasing concentrations in cold seasons. Due to anthropogenic similarities between CA and NH, the interactions among meteorological parameters and air pollutants were the same. High interaction was observed between PM2.5, naphthalene, and meteorological parameters. The integrated evaluation of the factors used by this study shows the relevance of obtaining these data for the prevention of human health.

Optimization and Interaction Analysis of Bacterial and Fungal Growth in the Presence of Benzo(A) Pyrene in Wastewater

In wastewater treatment plant, an aerobic approach is adopted in the system which utilize the ability of bacteria in the wastewater to reduce biochemical oxygen demand (BOD) and other organic pollutants. High molecular weight of polycyclic aromatic hydrocarbons (HMW-PAHs) are type of organic persistence and insoluble pollutants which hard to be removed from wastewater by bacteria. Owing to the HMW-PAHs tolerant characteristic and abundancy of fungi in wastewater, the bacteria and fungi interaction is anticipated to degrade the HMW-PAHs in wastewater. Thus, this study is carried out as a preliminary study to understand the interaction by optimized the bacterial and fungal growth in the presence of benzo[a]pyrene (BaP). Bacteria and fungi used in this study were Sphingobacterium spiritovorum and Aspergillus brasiliensis ATCC 16404. The response surface methodology (RSM) in Design-Expert® Version 7.0.0 software was used to analysed two factors which are pH and temperature on the bacterial and fungal growth. The growth of bacteria and fungi in co-culture and existence of BaP also been studied. The optimization study showed the growth of S. spiritovorum and A. brasiliensis was optimized at pH 6.2, temperature of 32 °C, and pH 6.5 and temperature of 33 °C, respectively. Synergy interaction was observed in the co-culture condition and with the existence of BaP. The present study provides beneficial information about the bacteria and fungi interaction which has the potential to be applied in the wastewater treatment plant.

Sedimentary polycyclic aromatic hydrocarbons (PAHs) along the mouth bar of the Yangtze River Estuary: Source, distribution, and potential toxicity

The source, distribution, and potential toxicity of sedimentary polycyclic aromatic hydrocarbons (PAHs) along the mouth bar of the Yangtze River Estuary were investigated. Total concentrations of 17 PAHs in the study area ranged from 34.94 to 580.26 ng/g (mean value 146.31 ng/g). Results of PMF model revealed that mixed vehicle emissions (38.43%), natural gas combustion (24.98%), biomass combustion (20.76%) and coal combustion (15.83%) were sources of these sedimentary PAHs. The ERL/ERM, TEL/PEL and TEC/PEC values showed that the potential toxicity of PAHs was at low to medium level, but the presence of benzo[a]pyrene (BaP) and benzo[e]pyrene (BeP) requires more attention and research. Sedimentary PAHs pollution level in the three shoals (East Nanhui Shoal, Jiuduansha Shoal and Hengsha Shoal) was higher than that of the two passages (South Passage and North Passage), which demonstrates the possibility of restoration of the adjacent shoals by dredged soils in terms of PAHs pollution.

Polycyclic aromatic hydrocarbons (PAHs) in mussels (Modiolus capax) from sites with increasing anthropogenic impact in La Paz Bay, Gulf of California

The composition, distribution and source of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments and tissues of the mussel Modiolus capax from three sites with increasing anthropogenic impact in La Paz Bay on the Gulf of California, were determined. Levels of total PAHs in sediments (18.9-94.5 ng/g dw) were below the effect range low for marine sediments at all sites. PAHs in mussels (147.01-271.09) were higher than in sediments and similar to mussels from other moderately contaminated sites. The origin of PAHs was predominantly petrogenic, attributed to port activities and a thermoelectric plant. The mussels of Las Pacas and Pichilingue showed the lowest condition indexes and some organisms with the presence of benzo(a)pyrene in their tissues, which is among the most toxic hydrocarbons and may represent a risk to human health. However, this study only represents a baseline for future studies, which are necessary to dismiss risks to human health and the ecosystem.

Polycyclic aromatic hydrocarbons in the bottom sediments of Elburgon River—Kenya: precursors for cancer

The exponential growth in the rate of industrialization is a serious precursor for contamination and deterioration of the environment. Water pollution, for instance, is expected to reach disturbing levels in the years to come. Polycyclic aromatic hydrocarbons (PAHs) in water systems are persistent contaminants not only in aquatic systems but also in soil, air and plant materials and are well-known initiators for cancer and gene mutation. Numerous human-dependent activities such as agriculture and suspected wood treatment works in Elburgon may lead to an increased PAH contamination of water in River Elburgon, especially when the internationally set limits are exceeded. The sediment samples were collected in May 2019 during the wet season and treated for analysis of PAHs using a gas chromatograph hyphenated to a mass selective detector. A total of 25 PAHs were quantified in this study out of which pyrene was the most abundant, contributing $$\approx \,17\%$$ of the total concentrations of PAHs identified. The total concentration of the PAHs analyzed in this study was found to be $$\mathop \sum \nolimits_{25} {\text{PAH}} = 73.19 \pm 3.67\;\upmu{\text{g}}\;{\text{g}}^{ - 1}$$ dry weight (dw) with pyrene contributing a total concentration $$\mathop \sum \nolimits_{\text{pyrene}} = 12.44 \pm 0.54\;\upmu{\text{g}}\;{\text{g}}^{ - 1 }$$ dw. On the other hand, benzo[a]pyrene (BaP)—a well-known carcinogen—was significantly high $$\mathop \sum \nolimits_{\text{BaP}} = 10.67 \pm 0.43\;\upmu{\text{g}}\;{\text{g}}^{ - 1 }$$ . Other major PAHs detected included acenaphthene and 5,6-dihydrobenzo[de]anthracene, $$14.57\%$$ and $$\approx \,11\%$$ , respectively. The low concentration PAHs included 1-ethenylnaphthalene and 1,4,5-trimethylnaphthalene each at $$0.08\%$$ . The presence of benzo[a]pyrene in significant amounts is of serious concern on the public health of the residents of Elburgon and its environs. Considering the high levels of PAHs in the sediments of River Elburgon, it is important to note with concern that the water in the river under study is not only be unsuitable for drinking but also unsuitable for other domestic purposes such as irrigation and laundry.

Application of Dopant-Assisted Atmospheric Pressure Photoionisation HPLC-MS Method for the Sensitive Determination of Polycyclic Aromatic Hydrocarbons in Dark Chocolate.

Multiple food research studies have shown that the polycyclic aromatic hydrocarbon (PAHs) are frequently found in processed cocoa products and chocolate. In a present study a method based on dopant-assisted atmospheric pressure photoionisation (DA-APPI) combined with a liquid chromatography/high-resolution mass spectrometer (HPLC-HRMS) for high-sensitivity analysis of four EU marker PAHs in dark chocolate samples was developed and fully validated according to the performance criteria set in EU guidelines. PAHs detection was achieved by HRMS in positive electrospray ionization mode with toluene used as a dopant to enhance the ionization efficiency of non-polar PAHs. The on-column instrument detection limits ranged from 0.8 to 1.2 pg for all four marker compounds. The method detection limits ranged from 0.016 to 0.024 μg kg-1 expressed on fat basis. The elaborated method was successfully applied to the analysis of four EU marker PAHs in dark chocolate samples. The presence of benzo[a]anthracene, benzo[b]fluoranthene and chrysene revealed at detectable levels in 100% of the samples, while benzo[a]pyrene was revealed in 77% of the samples, with its content ranging from 0.08 to 2.90 μg kg-1 fat.

The arbuscular mycorrhizal fungus Rhizophagus irregularis MUCL 41833 increases the phosphorus uptake and biomass of Medicago truncatula, a benzo[a]pyrene-tolerant plant species.

The accumulation of phosphorus (P) in plants increases their biomass and resistance/tolerance to organic pollutants. Both characteristics are mandatory for the utilization of plants in phytoremediation. Arbuscular mycorrhizal (AM) fungi improve plant P nutrition, and thus growth. However, only a few studies have focused on the dynamics of inorganic P (Pi) uptake in AM fungal-colonized plants in the presence of organic pollutants. Indeed, most of the results so far were obtained after harvesting the plants, thus by evaluating P concentration and content at a single time point. Here, we investigated the effects of the AM fungus Rhizophagus irregularis MUCL 41833 on the short-term Pi uptake dynamics of Medicago truncatula plants grown in the presence of benzo[a]pyrene (B[a]P), a polyaromatic hydrocarbon (PAH) frequently found in polluted soils. The study was conducted using a non-destructive circulatory semi-hydroponic cultivation system to investigate the short-term Pi depletion from a nutrient solution and as a corollary, the Pi uptake by the AM fungal-colonized and non-colonized plants. The growth, P concentration, and content of plants were also evaluated at harvest. The presence of B[a]P neither impacted the development of the AM fungus in the roots nor the plant growth and Pi uptake, suggesting a marked tolerance of both organisms to B[a]P pollution. A generally higher Pi uptake coupled with a higher accumulation of P in shoots and roots was noticed in AM fungal-colonized plants as compared to the non-colonized controls, irrespective of the presence or absence of B[a]P. Therefore, fungal-colonized plants showed the best growth. Furthermore, the beneficial effect provided by the presence of the AM fungus in roots was similar in presence or absence of B[a]P, thus opening the door for potential utilization in phytomanagement of PAH-polluted soils.

Pouteria ramiflora (Mart.) Radlk. extract: Flavonoids quantification and chemopreventive effect on HepG2 cells

ABSTRACTPouteria ramiflora (Mart.) Radlk., popularly known as curriola, is commonly used in Brazil as medicinal plant to treat worm infections, dysentery, pain, inflammation, hyperlipidemia, and obesity. At present the safety of this extract when used therapeutically in human remains to be determined. Thus, the aim of this study was to examine cytotoxicity, antiproliferative, and antimutagenic actions of this extract. The hydroalcoholic extract from P. ramiflora leaves consisted of flavonoids identified and quantified as myricetin-3-O-β-D-galactopyranoside (13.55 mg/g) and myricetin-3-O-α-L-rhamnopyranoside (9.61 mg/g). The extract exhibited cytotoxicity at concentrations higher than 1.5 µg/ml in human hepatocarcinoma (HepG2)and 2.5 µg/ml in non-tumoral primary gastric (GAS) cells using the MTT assay, and at concentrations higher than 3 µg/ml in HepG2 and 3.5 µg/ml in GAS cells by the neutral red assay. The extract did not show antiproliferative effect as evidenced by the nuclear division index (NDI). However, in the presence of benzo[a]pyrene (BaP) (positive control), an enhanced cytostatic effect in the NDI and flow cytometry was noted. It is of interest that when the extract was co-incubated with BaP a significant decrease in DNA damage was observed indicating an antimutagenic action. This protective effect might be attributed to myricetin and gallic acid found in P. ramiflora extract. The low cytotoxicity action and protective effect observed in the present study encourage further studies regarding other biological effects of P. ramiflora, as well as its potential use as a chemopreventive agent.

Functional data analysis, a new approach to aligning three-way liquid chromatographic with fluorescence detection data

Functional data analysis (FDA) arises as a promissory auxiliary methodology designed to help the analytical chemists, especially chemometricians. However, although the innovative ideas of this approach have barely spread into the chemical research field. In this work, a novel approach for aligning three-way chromatographic-spectral data based on FDA methodology is proposed. Unlike most of the available algorithms, this novel method allows performing data alignment when the test data matrix contains unexpected chemical interferences. Simulated and experimental analytical systems composed of calibrated analytes and potential interferents in the test samples are studied. The experimental system corresponds to the determination of the four polycyclic aromatic hydrocarbons (benzo[a]pyrene, dibenzo[a,h]anthracene, benzo[b]fluoranthene and benzo [k]fluoranthene) in the presence of benzo[j]fluoranthene and benzo[e]pyrene as potential interferences. These compounds are priority pollutants; hence, its reliable quantification in environmental samples is an analytical challenge. The method consists in decomposing the three-way data in each sensor mode and in making a functional alignment of the pure vectors obtained from the individual chromatograms of each analyte and interferent. The functional preprocessing step enables the analysis of the data set with second-order multivariate calibration algorithms, such as PARAFAC. The results illustrate that the proposed method restores the trilinearity of the three-way data, thus being able to successfully quantify the analytes in the presence of the interferences, that is, exploiting the second-order advantage. MCR-ALS is also applied to both simulated and experimental data to evaluate the performance of the PARAFAC second-order calibration model proposed. The performance of the PARAFAC and MCR-ALS models are compared and discussed.

Exposure and risk analysis to particulate matter, metals, and polycyclic aromatic hydrocarbon at different workplaces in Argentina.

In order to estimate air quality at work environments from small and medium-sized enterprises (SMEs), we determined both the concentration of particulate matter (PM10 and PM2.5) and the presence of polycyclic aromatic hydrocarbons (PAHs), as the heavy metals in the composition of the particulate matter. Three SMEs located in the city of La Plata, Argentina, were selected: an electromechanical repair and car painting center (ERCP), a sewing work room (SWR), and a chemical analysis laboratory (CAL). The results evidenced high levels of PM exceeding the limits allowed by the USEPA and the presence of benzo(k)fluoranthene in all the analyzed sites and benzo(a)pyrene in the most contaminated site (ERCP). Regarding metals, the presence of Cd, Ni, Cu, Pb, and Mn, mainly in the fraction of PM2.5, in the same workplace was found. As far as risk assessment at all the workplaces surveyed is concerned, risk values for contracting cancer throughout life for exposed workers (LCR) did not comply with the parameters either of USEPA or of WHO (World Health Organization).

Research Article Genetic expression of pobA and fabHB in Bacillus licheniformis M2-7 in the presence of benzo[a]pyrene

Bacillus licheniformis M2-7 is a heat-resistant bacterium able to biotransform polycyclic aromatic hydrocarbons. It can transform a wide range of these compounds as naphthalene, phenanthrene, pyrene and benzo[a]pyrene. Benzo[a]pyrene is a polycyclic aromatic hydrocarbon of high molecular weight considered as potentially toxic and carcinogenic for humans. Aiming to discover the genes involved in the biotransformation of benzo[a]pyrene, we made a B. licheniformis M2-7 genomic library in E. coli. We isolated two E. coli strains that were able to grow in minimal salt medium supplemented with benzo[a]pyrene. From the analysis of the DNA fragments in the clones H23 and H38, we identified open reading frames coding for 5 possible genes, among them pobA and fabHB, which products are the enzymes 4-hydroxybenzoate 3-monooxygenase and the ketoacyl-ACP synthase III, respectively. To evaluate the role of these genes in the metabolism of benzo[a]pyrene in B. licheniformis M2-7, we estimated their relative expression through reverse transcription quantitative PCR. Finally, we observed that the genes pobA and fabHB were overexpressed after 3 h under induction with benzo[a]pyrene, suggesting that this strain could use these genes during the metabolism of this PAH, plus it does it in a faster time than that reported for other bacterial genera

Application of Multivariate Curve Resolution-Alternate Least Square Technique on Extracting Pure Spectral Components from Multiple Emitting Systems: a Case Study.

Multiple emitting components in a fluorophoric system often produce complicated emission spectra. Extracting the individual spectral information from the composite spectra is important in order to comprehend the photophysical processes occurring in the multifluorophoric systems. Although the combination of Principal Component Analysis and Multivariate Curve Resolution-Alternate Least Square (PCA/MCR-ALS) technique is a well-known approach for curve deconvolution, its applicability in the spectral deconvolution of vibronically and electronically mixed up emitting systems as well as systems merged up with multiple electronic bands without a priori knowledge of the individual emitting species, is not properly studied. The present work highlights the strength of PCA/MCR-ALS in retrieving pure spectral information from the set of complex spectra arising out of the regular variation of causative factors that result in the variation of spectral composition. The retrieval of the emission bands utilizing the PCA/MCR-ALS technique has been made without having a priori information of the emitting species present in the multifluorophoric systems and the resolved spectra correspond well with the fluorescence spectra of the individual chemical species. The common curve fitting methods such as Gaussian and Lorentzian techniques have been found to be unsuccessful in providing meaningful photophysical information through the retrieved spectra. A comparative study of the curve fitting techniques MCR-ALS, Gaussian and Lorentzian in a set of complicated emission spectra of (i) pyrene and its excimer, (ii) pyrene and its excimer in presence of benzo[a]pyrene, and (iii) fisetin in bile salt medium is presented herein in details.

Atmospheric distribution of organic compounds from urban areas near Olympic games sites in Rio de Janeiro, Brazil

The hydrocarbon composition of atmospheric particulate matter (PM) and Volatile Organic Compounds (VOC) from urban areas of Rio de Janeiro City were studied to assess different pollution levels. PM samples were acquired using a standard high-volume air sampler (Hi-Vol), extracts were prepared and fractionated into aliphatic and aromatic compounds, and VOC compounds were collected in adsorbent tubes. High-resolution gas chromatography and GC coupled to mass spectrometry (GC-MS) were used to analyze the organic compounds from the PM and VOCs. The results showed that all samples contained n-alkanes, but the distribution was different for each sample, which reflects both biogenic (vascular plant wax input) and fossil fuel contamination sources (vehicular exhaust). Fossil fuel biomarkers, such as hopanes, were observed in all samples, but steranes were not detected in Marina da Gloria. The presence of benzo[a]pyrene was observed, and all measured concentrations were below the upper permissible limit. Benzene was also observed, and the upper limit value (5μg/m3) was exceeded in Jacarepagua (JP) and Maracanã (MC) according to the Ambient Air Quality and Cleaner Air for Europe limit value (EC, 2008). Regarding the Ambient Air Quality Criteria (AAQCs), all analyzed samples had concentration values above the limit of 2.30μg/m3. A decrease in pollution level was observed in the following order: Maracanã (MC), Guadalupe (GP), Jacarepagua (JP), Barra da Tijuca (BT), Vila Militar (VM) and Marina da Gloria (MG).

Growth-altering microbial interactions are responsive to chemical context.

Microbial interactions are ubiquitous in nature, and are equally as relevant to human wellbeing as the identities of the interacting microbes. However, microbial interactions are difficult to measure and characterize. Furthermore, there is growing evidence that they are not fixed, but dependent on environmental context. We present a novel workflow for inferring microbial interactions that integrates semi-automated image analysis with a colony stamping mechanism, with the overall effect of improving throughput and reproducibility of colony interaction assays. We apply our approach to infer interactions among bacterial species associated with the normal lung microbiome, and how those interactions are altered by the presence of benzo[a]pyrene, a carcinogenic compound found in cigarettes. We found that the presence of this single compound changed the interaction network, demonstrating that microbial interactions are indeed dynamic and responsive to local chemical context.

In Vitro Study on Quercetin Metabolism and Transport Rate in Presence of Benzo(a)pyrene

Quercetin is a flavonoid able to modify the metabolism of carcinogen benzo(a)pyrene in human intestinal cells but it is not known if its metabolism is affected by the presence of B(a)P. In this study the phase-2 metabolism and transport rate of quercetin has been studied using CaCo-2/TC7 cell line, model of human enterocytes, co-treated with B(a)P. Quercetin and its main metabolites, sulfated and glucuronidated, were quantified at different times (from T0 to T 24h), using HPLC with diode array and MS detection. This study showed that quercetin metabolism in CaCo-2/TC7 cells co-treated with B(a)P presents some differences respect to control in the formation of sulphates coniugates, more evident in the last time of analysis. The transport study, instead, confirmed a stronger influence of BaP with an increased rate of glucuronidation and sulfation of quercetin in both cellular side. The effects of B(a)P observed on phase-2 metabolism and transport rate of quercetin, by in vitro model of human enterocytes, put in evidence its possible influence, consequently, also on biological activities of this flavonoid.

Transcriptome analysis of Eisenia fetida chronically exposed to benzo(a)pyrene

Abstract Benzo(a)pyrene is a high molecular weight polycyclic aromatic hydrocarbon which is carcinogenic and widespread pollutant in the environment. It is essential to identify the presence of this chemical in soil as it is toxic to biota including humans. Eisenia fetida is a sentinel organism in soil which can be used to diagnose the health of the soil. In order to identify potential molecular markers from Eisenia fetida to diagnose the presence of benzo(a) pyrene in soil, we exposed the organism to sub-lethal ( 10 mg Kg −1 ) concentrations for a period of eight months and carried out transcriptome analysis. From the transcriptome, we have identified differentially expressed genes. Results showed that benzo(a)pyrene has altered the expression of calcium binding and calcium homeostasis, apoptotic process, cytoskeletal proteins, protein transport, nucleotide binding, lipid metabolism, peripheral neuronal development, cell division, wound healing and processing genes at transcription level. Several of the genes we reported here were not reported earlier. The highly up regulated and down regulated genes could be used as a molecular marker to diagnose the presence of benzo(a)pyrene in the soil.

Possible health risks from asbestos in drinking water

The recent finding of asbestos fibres in drinking water (up to 700.000 fibres/litres) in Tuscany (Central Italy) leads to concerns about health risks in exposed communities. Exposure to asbestos has been linked with cancer at several levels of the gastrointestinal tract, and it has been documented, in an animal model, a direct cytotoxic effect of asbestos fibres on the ileum. It has been recently described a possible link between asbestos and intrahepatic cholangiocarcinoma, and asbestos fibres have been detected in humans in histological samples from colon cancer and in gallbladder bile. Taken together, these findings suggest the possibility of an enterohepatic translocation of asbestos fibres, alternative to lymphatic translocation from lungs. In animal models, asbestos fibres ingested with drinking water act as a co-carcinogen in the presence of benzo(a) pyrene and, according to the International Agency for Research on Cancer (IARC ), there is evidence pointing to a causal effect of ingested asbestos on gastric and colorectal cancer. The risk seems to be proportional to the concentration of ingested fibres, to the extent of individual water consumption, to exposure timing, and to the possible exposure to other toxics (i.e., benzo(a)pyrene). Furthermore, the exposure to asbestos by ingestion could explain the epidemiological finding of mesothelioma in subjects certainly unexposed by inhalation. In conclusion, several findings suggest that health risks from asbestos could not exclusively derive from inhalation of fibres. Health hazards might also be present after ingestion, mainly after daily ingestion of drinking water for long periods. In Italy, a systemic assessment of the presence of asbestos fibres in drinking water is still lacking, although asbestos-coated pipelines are widely diffused and still operating. Despite the fact that the existence of a threshold level for health risks linked to the presence of asbestos in drinking water is still under debate, the precautionary principle should impose all possible efforts in order to revise health policies concerning this topic, and a systematic monitoring of drinking water to quantify the presence of asbestos is certainly needed in all regions. Further epidemiological studies aimed to the identification of exposed communities and to an adequate health risk assessment in their specific geographical areas are urgently needed.