Benzo[b]fluoranthene Research Articles

Effect of Ambient PM2.5-Bound BbFA and DahA on Small Airway Dysfunction of Primary Schoolchildren in Northeast China.

Given the lack of research on the schoolchildren exposure to PM2.5-bound PHAs in northeast China, we investigated the effects of exposure to ambient benzo[b]fluoranthene (BbFA) and dibenz[a,h]anthracene (DahA) bound to PM2.5 on pulmonary ventilation dysfunction (PVD) and small airway dysfunction (SAD). PM2.5 samples at two schools (A and B) were collected, and the concentrations of PM2.5-bound 4–6-ring PAHs were analyzed. PVD and SAD were evaluated by pulmonary function tests in 306 students while urinary MDA and CRP levels were measured. The results confirmed that ambient PM2.5-bound 4–6-ring PHA levels were significantly higher and the PVD and SAD incidence in schools A and B were increased during the heating season. We found that PM2.5-bound BbFA, BkFA, BaP, and DahA levels were only correlated with SAD in schoolchildren; the correlation coefficients of BbFA and DahA were the highest effect estimates, possibly due to altered MDA levels. Therefore, this research enables us to better understand the effects of exposure to ambient PM2.5-bound PHAs on pulmonary function parameters. Our results also showed that identification of hazardous PM2.5-bound BbFA and DahA to health is crucial for preventing the respiratory-related diseases.

Source profile and excess cancer risk evaluation of environmental tobacco smoking under real conditions, China

To demonstrate the chemical characteristics and carcinogenic risk of environmental tobacco smoke (ETS) emission, replicate PM2.5 samples were collected via volunteers smoking nine different brands of Chinese cigarettes. The source profile of ETS was established with an abundance of inorganic and organic chemical compositions, source signatures were recognized, and a comparison of excess cancer risk of heavy metals versus polycyclic aromatic hydrocarbons (PAHs) was completed. The results showed that organic carbon (OC), element carbon (EC) and potassium (K) were the primary components in the ETS profile; chromium (Cr), lead (Pb) and cadmium (Cd) were the most abundant heavy metals; and PAHs were mainly distributed in middle molecular weight (MMW) and high molecular weight (HMW) ranges. Benz(a)anthracene (BaA), benzo(b)fluoranthene (BbF) and chrysene (CHR) could distinguish ETS from cooking/outdoor stationary sources as source-related markers. The ranking of excess cancer risk of heavy metals was Cr > Cd > arsenic (As) > Pb > nickel (Ni) and that of PAHs was benzo(a)pyrene (BaP) > BaA > BbF > indeno(1,2,3-cd)pyrene (IND) > CHR. The comparison revealed that the totality of excess cancer risk of heavy metals was 785 times higher than that of PAHs, indicating that the harmful health effect caused by inorganic compositions during ETS exposure should attract public attention.

High cancer risk from inhalation exposure to PAHs in Fenhe Plain in winter: A particulate size distribution-based study

Fenhe Plain is a typical region polluted combinedly by coal combustion and coking activities with serious air pollution problem, especially in winter. In order to clarify the size distribution and health risk of polycyclic aromatic hydrocarbons (PAHs) in winter of the Fenhe Plain, the respirable aerosol particles (PM10) were collected by cascade impactor, and 17 PAHs were analyzed. The results showed that the average mass concentration of PM10-bound PAHs was 689.19 ng/m3, which was higher than that in many other domestic and overseas cities. The particulate PAHs mainly distributed in the <0.95 μm size range, accounting for more than 60% of the total. Under the combined influence of local emissions, low temperature, low intensity of solar radiation, dry atmosphere and Kelvin effect, naphthalene (Nap) displayed a bimodal distribution, while the rest of the 17 PAHs all followed a nearly unimodal size distribution. Wind and humidity were important factors which could influence the size distribution of PAHs. Coefficient of divergence (CD) analysis showed that PAHs between all of the sizes had a high spatial heterogeneity in source factor contributions, although diagnostic ratio indicated similar sources among them. Health risk assessment found that the lifetime cancer risk of exposure to particulate PAHs was 1693.76 parts per million people. Ultrafine particles (<0.95 μm) predominated the total carcinogenicity of the particulate PAHs, while benzo(a)pyrene (BaP), dibenzo(a,h)anthracene (DahA), benzo(b)fluoranthene (BbF), benzo(a)anthracene (BaA), benzo(k)fluoranthene (BkF) and indeno(1,2,3-cd)pyrene (IcdP) were the major carcinogenic components. Traffic exhausts contributed most to the carcinogenic PAHs, followed by coal combustion and coking. Our study can provide reference for the pollution control and residential health protection in Fenhe Plain, and bring more reasonable parameterizations to the estimation of PAHs outflow from this key region to other international regions.

Comparison of common spatial interpolation methods for analyzing pollutant spatial distributions at contaminated sites

Accurate prediction of the spatial distribution of pollutants in soils based on applicable interpolation methods is often the basis for soil remediation in contaminated sites. However, the applicable interpolation method has not been determined for contaminated sites due to the complex spatial distribution characteristics and stronger local spatial variability of pollutants. In this research, the prediction accuracies of three interpolation methods (including the different values of their parameters) for the spatial distribution of benzo[b]fluoranthene (BbF) in four soil layers were compared. These included inverse distance weighting (IDW), radial basis function (RBF), ordinary kriging (OK). The results indicated: (1) IDW1 is applicable for the first layer, RBF-IMQ is applicable to the second, third, and fourth layers. (2) For IDW, the prediction error is bigger with high weight where high values and low values intersect, while the prediction error is smaller where high (or low) values aggregated distribution. (3) For RBF, if the pollutant concentration trend at the predicted location is consistent with the known points in its neighborhood, the prediction accuracy is higher. (4) IDW is suitable for fitting more drastic curved surfaces, while RBF is more effective for relatively gentle curved surfaces and OK is reasonable for curved surfaces without local outliers. (5) The interpolation uncertainty is positively associated with the contaminant concentration and local spatial variability. Therefore, we suggest the selection of the applicable interpolation model must be based on the principle of the model and the spatial distribution characteristics of the pollutants.

Comamonas sp. 3ah48 is a dibenz[a,h]anthracene-degrading bacterium that is tolerant to heavy metals.

Industrialization often causes polycyclic aromatic hydrocarbon (PAH) and heavy metal contamination of soil and water. In this study, we isolated a bacterium from bottom mud water around a park of Kawasaki Port, Japan, that degrades the 5-ring PAH dibenz[a,h]anthracene (DBA). The strain, Comamonas sp. 3ah48, degraded 29% of DBA (30μg ml-1 ) in 7days, and the degradation level increased drastically, to 59%, by the addition of glutamate to the medium. The strain also degraded 40, 14, 15 and 19% of pyrene (Pyr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF) and benzo[g,h,i]perylene (BghiP) respectively. Benzo[a]pyrene (BaP) was degraded only when glutamate was added to the medium. Strain 3ah48 retained its degradation levels in the presence of 2mmol l-1 Co2+ , Zn2+ or Cr2+ , at almost the same level as that without metal, and increased the DBA degradation level to 57% in the presence of 2mmol l-1 Cu2+ , suggesting the possibility of the presence of laccase. SIGNIFICANCE AND IMPACT OF THE STUDY: Sixteen polycyclic aromatic hydrocarbons (PAHs) are listed as priority pollutants by the United States Environmental Protection Agency (USEPA). Information about the biodegradation of one of those PAHs, dibenz[a,h]anthracene (DBA), is limited. The present study focuses on DBA degradation by Comamonas sp. 3ah48 strain isolated around Kawasaki Port, Japan. Comamonas sp. 3ah48, cultured with the addition of glutamate to the medium, was found to increase the degradation level of DBA and to degrade DBA even in the presence of high concentrations of heavy metals.

Discrimination of polycyclic aromatic hydrocarbons based on fluorescence spectrometry coupled with CS-SVM

A new approach for discrimination of polycyclic aromatic hydrocarbons (PAHs) in environment was proposed based on fluorescence coupled with CS-SVM. Two groups of experiments were carried out on PAHs with similar spectra. The first one was PAHs any two among benzo[k]fluoranthene (BkF), benzo[b]fluoranthene (BbF) and benzo[a]pyrene (BaP). The second one was naphthalene (NAP) and fluorene (FLU) with similar spectra. The BaP-BkF mixture, BaP-BbF mixture and BbF-BkF mixture with similar fluorescence properties, cuckoo search algorithm (CS) optimizing support vector machine (SVM) was used to discriminate these three mixtures. By comparison with the basic grid search algorithm (GS), genetic algorithm (GA) and particle swarm optimization algorithm (PSO) optimizing SVM, it was found that fitting degree of CS was the best and the convergence speed was also the fastest. The test sample classification accuracy of CS-SVM can reach 100%, which was higher than that of GS-SVM, GA-SVM and PSO-SVM. In order to verify the validity of the proposed approach, all the above methods were applied to discriminate NAP and FLU with extremely similar spectra. The test sample classification accuracy can reach 100%. The satisfying results indicated that the proposed approach had potential to be an alternative approach for discriminating PAHs in environment.

In Vitro investigations of high molecular weight polycyclic aromatic hydrocarbons in winter airborne particles using simulated lung fluids

This study evaluated the bioaccessibility of 9 high molecular weight polycyclic aromatic hydrocarbons (PAH9) in airborne particulate matter (PM) by employing a physiological extraction test with simulated lung fluids [Gamble's solution and artificial lysosomal fluid (ALF)]. Airborne PM samples (PM2.5) were collected during the non-heating and heating periods in Harbin, a city in Northeast China. All PAH9 were detectable in the PM2.5 fractions. Indeno[1,2,3-c,d]pyrene (Ind), benzo[a]pyrene (BaP) and benzo[b]fluoranthene (BbF) were the most common PAH9 species detected. After Gamble's solution extraction, PM2.5-bound PAH9 bioaccessibility was significantly higher (p < 0.05) compared to its after ALF extraction. We estimated the lifetime excess inhalation cancer risks per million people owing to exposure to total PAH9 to be 29.1–69.8 and 141–477 cancer cases per million people during the non-heating and heating periods, respectively, while these numbers were reduced to 1.90–11.3 and 5.90–32.8 after Gamble's solution extraction (decreases of 90.7% and 92.7%) and 2.10–7.00 and 2.80–19.9 after ALF extraction (decreases of 92.6% and 97.3%). Predictions of pulmonary toxicity caused by airborne PM upon inhalation might be overestimated if the bioaccessibility and potential toxicity of PM2.5-bound PAH9 are not fully evaluated.

Ingestion bioaccessibility of indoor dust-bound PAHs: Inclusion of a sorption sink to simulate passive transfer across the small intestine

In this study, we investigated the levels of 12 priority polycyclic aromatic hydrocarbons (PAH12) pollutants, bioaccessible PAH12, and sorption sink for PAH12 by a silicone sheet of indoor dust samples, which were collected from teachers' offices (n = 17), students' offices (n = 17), laboratory (n = 11), and experimental center (n = 9), using an in vitro digestive model. In PAH12, bioaccessible PAH12, and sorption sink PAH12, benzo[b]fluoranthene (BbF), phenanthrenes (Phe), and fluoranthene (FLA) were labeled respectively the most significant PAHs (6.61 ± 4.42 μg/g, 0.16 ± 0.11 μg/g, and 0.08 ± 0.06 μg/g) after indoor dust ingestion, whereas the proportions of anthracene (Ant), benzo(g,h,i)perylene (BghiP), and BghiP (0.34 ± 0.17, 0.03 ± 0.03 and 0.01 ± 0.01 μg/g) were low. Based on benzo[a]pyrene- equivalent carcinogenic concentrations, the mean daily exposure of bioaccessible PAH12 and sorption sink for PAH12 by indoor dust ingestion was 4.07 × 10−3 ± 1.73 × 10−3 and 3.23 × 10−3 ± 1.36 × 10−3 μg/day in the experimental center; 4.01 × 10−3 ± 2.05 × 10−3 and 1.46 × 10−3 ± 6.72 × 10−4 μg/day in students' offices; 8.25 × 10−4 ± 2.33 × 10−4 and 5.15 × 10−4 ± 1.37 × 10−4 μg/day in laboratory; and 7.05 × 10−4 ± 4.12 × 10−5 and 2.82 × 10−4 ± 4.36 × 10−5 μg/day in teachers' offices, respectively. Our results indicated that the passive transfer fraction of PAH12 (44.07%–67.36% in this case) is therefore large and needs to be considered in exposure and risk assessments.

In vitro removal of polycyclic aromatic hydrocarbons by lactic acid bacteria.

The current study aimed to investigate the ability of lactic acid bacteria (LABs) in removing four polycyclic aromatic hydrocarbons (PAHs) namely, benzo(a)pyrene (BaP), benz(a)anthracene (BaA), chrysene (Chr) and benzo(b)fluoranthene (BbF) from contaminated phosphate buffer saline (PBS). The effect of initial PAH concentrations (5, 10, 15, 20μgml-1 ), bacterial population (107 , 108 , 109 , 1010 CFU per ml) and pH (3, 5, 7) was studied to evaluate bacterial binding ability. All the tested bacteria could remove BaA, Chr, BbF and BaP from phosphate buffer solution and in almost all assays, removing of PAHs was as follows: BaP>Chr>BaA>BaF. Bifidobacterium lactis BB-12 had the lowest binding rate for all four PAHs, while the highest binding ability was related to Lactobacillus acidophilus LA-5. Moreover, cell viability was not required for the binding ability and even acid-treated, heat-treated and ultrasonic-treated bacterial cells showed more binding ability. The results showed that the bacteria-PAH complex was irreversible after washing with PBS. The removal of PAHs was significantly related to pH of media, strains of bacteria, type and concentration of PAHs SIGNIFICANCE AND IMPACT OF THE STUDY: This study has been focused on the reduction of polycyclic aromatic hydrocarbons using LABs and probiotics. Our results showed that not only live strains but also inactivated tested strains are able to remove PAHs from aqueous media, presenting new methods to diminish the amount of these contaminants in foods. Furthermore, the results of this study can be used in future research on evaluating the effects of oral administration of probiotic supplements and even dead probiotic strains on reducing PAHs in humans.

Bioaccessibility of polycyclic aromatic hydrocarbons in central air conditioner filter dust and its occupational exposure to shopping mall employees

The assessment of the human health risk of dust exposure to polycyclic aromatic hydrocarbons (PAHs) has been hampered by a lack of data on the bioaccessibility. The purpose of this study was to apply in vitro methods using simulated lungs with artificial lysosomal fluid (ALF) and Gamble's solution and digestive fluid to assess the bioaccessibility of 8 high molecular weight PAH (PAH8) in central air conditioner (AC) filter dust from a shopping mall in northeast China. Overall, the bioaccessible PAH8 concentration (μg/g) in AC filter dust samples after ALF and Gamble's solution extraction for 24 h were notable, with a mean of 1.71 ± 0.6 and 1.92 ± 0.5 in the sales areas, and a mean of 1.61 ± 0.2 and 1.85 ± 0.2 in the office areas. AC filter dust exposed to simulated digestive fluid had a mean bioaccessible PAH8 concentration (μg/g) of 1.60 ± 0.4 in the sales areas and 1.15 ± 0.2 in the office areas. Benzo[b]fluoranthene (BbF) made the most significant contribution to the total and bioaccessible PAH8 concentrations in all of the AC filter dust after simulated digestive fluid extraction, while the bioaccessibility was driven by chrysene (Chr, sales areas) and indeno[1,2,3-c,d]pyrene (Ind, office areas). Both the bioaccessibility and concentration of PAH8 in simulated lung fluid were mainly driven by benzo[a]pyrene (BaP). This study highlights the need to conduct bioaccessibility experiments for an adequate exposure assessment of health risk.

A novel computational solution to the health risk assessment of air pollution via joint toxicity prediction: A case study on selected PAH binary mixtures in particulate matters

Regional haze episode has already caused overwhelming public concern. Unraveling the health effects of the representative composition mixtures of atmospheric fine particulate matters (PM2.5) becomes a top priority. In this study, a novel computational solution integrating chemical-induced genomic residual effect prediction with in vitro-based risk assessment is proposed to obtain the cumulative health risk of typical chemical mixtures of particulate matters (PM). The joint toxicity of binary mixtures is estimated by analyzing both genomic similarity and dose-response curve of relevant pollutants for the chemical-induced genomic residual effect. Specifically, the modified relative potency factor (mRPF) of mixtures is introduced for this purpose, and the ratio of activation (RA) value is defined to assess the corresponding health risks of the mixtures. As a methodology demonstration, the health risk of typical binary polycyclic aromatic hydrocarbon (PAH) mixtures in PM, containing Benzo[a]pyrene (BaP) as a component, is assessed using the proposed solution. Our results indicate that the combined effect of pairwise PAHs of BaP with Benzo[b]fluoranthene (BbF) and Benz[a]anthracene (BaA) is synergistic on p53 pathway, and that the health risk of the such mixtures increases compared to that of the individual ones. Obviously, the cumulative health risk of environmental mixtures will be underestimated when the synergistic effect is wrongly assumed to be additive. To our knowledge, this is the first study ever report on a computational solution to the health risk assessment of environmental pollution via joint toxicity prediction. The novel methodology proposed here makes full use of the open-access in vitro assay data and transcriptomic information in literatures and provides a successful demonstration of the concept of systems biology and translational science.

Polycyclic aromatic hydrocarbons in urban road dust, Afghanistan: Implications for human health

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in road and aerial dust to assess their concentration, composition profile, distribution, emission sources, and potential human health risks. Sixteen priority PAHs and Benzo [e]pyrene (BeP) were analyzed in 13 aerial dust samples from Jalalabad, and 78 road dust samples from Kabul and Jalalabad cities, Afghanistan. The mean concentration of ∑17PAHs in road dust from Kabul and Jalalabad were 427 μg kg−1 and 288 μg kg−1, respectively whereas ∑17PAHs in aerial dust from Jalalabad averaged 200 μg kg−1. Fluoranthene (Flu), Chrysene (Chr), Benzo [b]fluoranthene (BbF), Benzo [k]fluoranthene (BkF) and BeP were major individual PAH species. The composition patterns of the PAHs were dominated by 5-6-ring PAHs (51% in road dust from Kabul; 44% in road dust from Jalalabad; and 44% in aerial dust) followed by 4-ring and 2-3-ring PAHs. Source apportionment of the road dust PAHs by the molecular diagnostic ratios (MDR) and principal component analysis (PCA), indicated signatures of PAHs sources (including vehicular exhaust, coal/wood combustion and oil spill). The Benzo [a]pyrene (BaP) toxicity equivalent values (BaPeq17PAHs) for road dust were 75 μg kg−1 (Kabul) and 36 μg kg−1 (Jalalabad); and 35 μg kg−1 for aerial dust (Jalalabad). BaP and Dibenz [a,h]anthracene (DahA) together contributed > 50% of the BaPeq associated cancer risk. All incremental lifetime cancer risk (ILCR) due to human exposure to road and aerial dust PAHs were in the order of 10−7, which is one-fold lower than the threshold (10−6). The noncancerous risk (Hazard Index < 1) on exposure to dust was also negligible for both subpopulations.

Concentration and sources of fine particulate associated polycyclic aromatic hydrocarbons at two locations in the western coast of India.

PM2.5 particulate matter (PM) and their associated polycyclic aromatic hydrocarbons (PAHs) were studied at Urban and Sub-urban sites in the western coast of India. The concentration of PM2.5 ranged from 66.29 μg m-3 to 182.15 μg m-3, being the highest at Sub-urban site than the urban site. There were total six carcinogenic PAHs found to be dominated in particulate samples at these locations. The general trends observed for individual carcinogenic PAHs concentration at urban location was, benzo(a)pyrene (BaP)<benzo(k)fluoranthene (BkF)<benzo(ghi)perylene (BghiP)<benzo(b)fluoranthene (BbF)<benzo(e)pyrene (BeP)<indeno(1,2,3-cd)pyrene (I123P). Whereas, at Sub-urban location the concentration was found to be, (BaP) < (BkF) < (BeP) < (BghiP) < (I123P) < (BbF). PAHs diagnostic ratio and Principal component analysis was used to find out the main sources of PAHs. The results of PAHs diagnostic ratio and Principal component analysis revealed that vehicular emission of gasoline and diesel powered vehicles were the main source of individual PAHs at both the locations. BaP equivalent exposure (BaPeq) were calculated to find out the total carcinogenicity of PAHs at both sites, and the results revealed that the mean concentration of PAHs were found to be lower when their contributions to carcinogenicity were taken into account.

The occurrence of polycyclic aromatic hydrocarbons in fish and meat products of Croatia and dietary exposure

For the first time, the levels of benzo(a)anthracene (BaA), chrysene (CHR), benzo(b)fluoranthene (BbF) and benzo(a)pyrene (BaP) and their sum (PAH4) were investigated in a total of 180 samples of fish, shellfish and meat products produced in Croatia. In addition, dietary polycyclic aromatic hydrocarbons (PAHs) intake of adult Croatian consumers was estimated for both acute and chronic ingestion circumstances. None of the food samples exceeded the currently legal PAHs levels according to the European legislation. The mean PAH4 level was 1.47 μg/kg for meat and 1.48 μg/kg for shellfish products. The acute daily ingestion of BaP and PAH4 through meat and shellfish products was 2‒ to 7‒ fold higher in comparison to chronic intake, with meat products being the major contributors. Consequently, the evaluation of consumption patterns that used the margin-of-exposure approach indicated a negligible risk to human health.

Particle-Bound Polycyclic Aromatic Hydrocarbon in the Atmosphere of Heavy Traffic Areas in Greater Cairo, Egypt: Status, Source, and Human Health Risk Assessment

Airborne particulate samples were collected from three main squares (Ramsis, El Giza, and Sphinx) representing heavy traffic areas in Greater Cairo during the period of December 2015–February 2016, and analysed for polycyclic aromatic hydrocarbon (PAHs). The maximum concentrations of particle-bound PAHs were observed at El Giza, while the minimum levels were recorded at Sphinx. The levels of particle-bound PAHs in the square areas of Greater Cairo are higher than those found in many different locations in Egypt and around the world.The distribution of individual particle-bound PAHs as well as PAH categories, depending on the ring number in Ramsis, El Giza, and Sphinx, wasquite similar. This similarity implies similar emission sources of PAHs in the three square areas, with vehicle exhaust emissions being the dominant one. Benzo[b]fluoranthene (BbF), benzo[ghi]perylene (BGP), and indeno[1,2,3-cd]pyrene(IND) were the most abundant PAH compounds. Diagnostic concentration ratios of PAH compounds in the three square locations suggest that both petrogenic and pyrogenic sources emit these compounds. Moreover, they originate mainly from traffic emissions in the study areas. Based on the calculated benzo[a]pyrene equivalent (BaPeq) for the individual particle-bound PAH compounds, health risks associated with the inhalation of these compounds were assessed. Total carcinogenic activity (TCA) for all measured PAHs represented 20.03% (El Giza), 20.40% (Ramsis), and 20.60% (Sphinx) of the total PAH concentrations. Benzo[a]pyrene (BaP) and dibenz[a,h]anthracene (DBA) were the highest contributors to the total health risks; these accounted for 42.72% and 38.50% (El Giza), 41.79% and 39.17% (Ramsis), and 42.92% and 37.78% (Sphinx) of the TCA of all PAH compounds, respectively. These results indicate the importance of BaP and DBA as surrogate compounds for PAHs in the atmosphere of square areas of Greater Cairo.

Polycyclic aromatic hydrocarbons in soil of the backfilled region in the Wuda coal fire area, Inner Mongolia, China

The Wuda coal fire area in Inner Mongolia, China, has existed for 50 years and been controlled by digging and backfilling for many years. However, few studies have focused on its impact on the local environmental and ecological systems due to emission of organic contaminants from the backfilled region. In the study, topsoil samples were collected at a 0–5 cm depth from the backfilled region of the Wuda coal fire area, which has existed for five years. The samples were analyzed for 16 priority control contaminants, namely polycyclic aromatic hydrocarbons (PAHs), with a standard operation procedure and high-performance liquid chromatograph (HPLC). The results showed that the total mass contentration of 16 PAHs (∑16PAHs) ranged from 279 to 8258 μg kg-1, with an average value of 2853 ± 2948 µg kg-1, which exceeded the stipulated limit for heavily contaminated soil (1000 μg kg-1). Among the 16 PAHs, 2- and 3-ring compounds accounted for more than half of ∑16PAHs. Furthermore, the results show that the main contaminants were the naphthalene (Nap), phenanthrene (Phe), pyrene (Pyr), chrysene (Chr), and benzo[b]fluoranthene (BbF) in this area (24.8%, 51.1%, 3.9%, 4.5%, and 5.7% of ∑16PAHs, respectively). The diagnostic ratio of FLA/(FLA + PYR) exceeded 0.4 and IcdP/(IcdP + BghiP) was less than 0.5, indicating gentle smoldering or spontaneous combustion of coal fire, which differs from traditional coal burning. The environmental health risk or specifically the cancer risk (CR), calculated using the surface soil of the backfilled region, was 2.84 × 10-6 for adults and 1.01 × 10-6 for children, thus indicating potential cancer risks. Therefore, PAHs pollution in the surface soil of the backfilled region in the studied coal fire area is an issue that deserves urgent attention.

Performance evaluation of a pellet based column bed for removal of a potentially carcinogenic Polycyclic Aromatic Hydrocarbon (PAH) from water

Performance of a novel prototype of a column-bed was evaluated for the removal of a potentially toxic Polycyclic Aromatic Hydrocarbon (PAH) - Benzo(b)fluoranthene (BbF) from the water. The column-bed was prepared using the pellets fabricated from a mixture of low-cost materials: Plaster of Paris (POP), Coconut coir and Zeolite. The pellets were coated with a unique combination of bioadsorbents (Chitosan and Alginic acid) for enhanced removal, greater stability, and reusability of pellets. The pellet based column- bed showed up to 91% removal efficiency during 120 min treatment time in graded concentrations ranging from 0.01 to 10.0 ppm. Evaluation of kinetic behavior of the column was performed through linear regression analysis by fitting the data into three well-known models: Thomas, Adams-Bohart, and Yoon-Nelson. The data showed good agreement between experimental and calculated values of adsorption capacity (qe) for all the models, however Adams-Bohart model fitted best to the data obtained. This report provides a novel design of a column bed-reactor for PAH removal from water. The pelleted form of packing material for column-bed is a unique approach to enhancing the column efficiency and reusability of the materials used for column-bed preparation.

Determination and risk characterization of polycyclic aromatic hydrocarbons of tea by using the Margin of Exposure (MOE) approach.

Tea is one of the most frequently consumed drinks due to its favourite taste and the health benefit. Tea is produced by several processes and drying is very important step to develop the flavour and destroys the enzymes in tea. However, during drying tea, polycyclic aromatic hydrocarbons some of which are carcinogen and genotoxin are naturally produced. The risk of PAHs by drinking tea was characterized by determining contents of 4 PAHs in tea. 4 PAHs including Benz(a)anthracene (BaA), Chrysene (CHR), Benzo(b)fluoranthene (BbF) and Benzo(a)pyrene (BaP) were investigated by GC-MS in total 468 tea products, which were contaminated up to 4.63ngg-1. Mate tea was the most highly contaminated by BaA, CHR, BbF and BaP and followed by Solomon's seal and Chrysanthemum. The Margin of Exposures calculated by the concentration of BaA, CHR, BbF and BaP and consumption amount of tea were higher than 10,000, and the risk of PAHs in tea were low concern to public health.

Analytical Method Validation and Rapid Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Cocoa Butter Using HPLC-FLD

A simple, fast and ecological analytical method using a semi-automatic fat extractor and HPLC-FLD (fluorescence detection) for determination of polycyclic aromatic hydrocarbon markers i.e. benzo(a)anthracene (BaA), chrysene (Chr), benzo(a)pyrene (BaP) and benzo(b)fluoranthene (BbF) in cocoa butter has been validated. Validation’s procedure performed out in concordance with French standard NF V03-110 (2010) was based on existing polycyclic aromatic hydrocarbon (PAH) determination methods in various smoked foodstuffs and edible vegetable oils. Determination of correlation coefficients for specific PAHs ranged from 0.9992 to 0.9998. Respective values of limits of detection were 0.010, 0.011, 0.033 and 0.029 μg kg−1 and those of quantification were 0.035, 0.038, 0.111 and 0.098 μg kg−1 for BaA, Chr, BbF and BaP. Both values of repeatability and intermediary precision tests coefficients of variation were less than 5%. Recovery scores of four PAH markers matched EU standard 836/2011 recommendations. Sum of four PAH markers (BaA, Chr, BbF, BaP) contents varied from 5.42 ± 0.58 to 11.37 ± 0.01 μg kg−1 whereas those of BaP was comprised between 0.26 ± 0.00 and 1.75 ± 0.13 μg kg−1 in 20 cocoa butter samples extracted from raw cocoa bean stored at Ivorian cocoa farmer levels.

Impact of pyrolysis conditions on polycyclic aromatic hydrocarbons (PAHs) formation in particulate matter (PM) during sewage sludge pyrolysis

Polycyclic aromatic hydrocarbons (PAHs) not only present a risk to human health when released into the air, but also can be precursors to form particulate matter (PM) during sewage sludge pyrolysis. In this study, 16 EPA PAHs in PM (ΣPAHPM) during sewage sludge pyrolysis were investigated with increasing temperature (200oC–1000 °C) and holding time under different operation conditions [inert gas flow rate (IGFR) (200–800 mL/min) and heating rate (5–20 °C/min)]. ΣPAHPM varied with temperature, IGFR, and heating rate, and ranged from 597 (±41) μg/g to 3240 (±868) μg/g. ΣPAHPM decreased with increasing IGFR but increased with rapid heating rate. Among PAHs species in PM, naphthalene (Nap) was commonly detected at low temperature ranges in all tested conditions. Chrysene (CHR), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[1,2,3-cd] pyrene (IND), and benzo[g,h,i]perylene (BghiP) in PM became abundant at high temperature with a low IGFR. At high temperature ranges with high volatile conditions (rapid heating rate and low IGFR), PAH formation and growth reactions were considerable, resulting in the formation of heavy PAHs in PM.