Occurrence and Source Apportionment of Polycyclic Aromatic Hydrocarbons in Urban Residential Soils from National Capital Region,Uttar Pradesh,India

This study aims to investigate the level of priority polycyclic aromatic hydrocarbons (PAHs) and identification of their potential sources in residential soils. During the study, a total 36 soil samples collected from twelve residential locations at Sahibabad-Ghaziabad area of western Uttar Pradesh, India, a constituted part of the National Capital Region of India. Samples extracted using ultrasonication, cleaned with silica and analyzed by diode array detector–high-performance liquid chromatography using acetonitrile/water as mobile phase. The 25th and 75th percentile concentration of ∑PAHs was 264 μg kg^?1 and 584 μg kg^?1, respectively, with mean and median of 445 μg kg^?1 and 421 μg kg^?1. The detection frequency of PAHs in all samples was lower for low molecular weight PAHs (19%) than high molecular weight PAHs (81%). The concentration of seven probable carcinogenic PAHs accounted for 67% of the ∑PAHs. PAHs toxicity potential as benzo(a)pyrene toxicity equivalent ranged between 2.52–253 μg BaP_TEQ kg^?1. Composition profile of PAHs with different aromatic rings and selected diagnostic molecular ratios suggested the local pyrogenic sources of PAHs from vehicular emissions, diesel engines, biomass combustion, gasoline, and coal combustions.     

Characterization of PM2.5-Bound Polycyclic Aromatic Hydrocarbons in the Ambient Air of Győr,Hungary

ABSTRACT

In Hungary, the nationwide monitoring of PM10-bound polycyclic aromatic hydrocarbons (PAHs) in ambient air is great importance for a number of reasons related to human health, the environment and compliance with European Union legislation. However, the measurement of PAH concentrations in PM2.5 aerosol fraction has not been carried out. Therefore, the concentration, distribution and sources of PM2.5-bound PAHs at different urban sites of Gy?r were investigated in a heating season. The total PAH concentrations (sum of 19 individual PAH compounds) ranged from 1.32 to 37.27 ng/m³ with the mean value of 10.54 ng/m³. The high molecular weight PAHs with 5 and 6 aromatic rings were the most abundant PAHs in PM2.5 aerosol samples, which averaged 82% of total PAHs. Using benzo(a)pyrene (BaP) equivalent approach on the concentration data of carcinogenic PAH species, BaP and indeno(1,2,3-cd)pyrene contributed the highest carcinogenic exposure equivalent (1.25 and 0.19 ng/m³ on average). However, the incremental lifetime cancer risk (ILCR) values for resident children and adults indicated low-potential cancer risk (ILCR < 10^?6). The source apportionment results reflected that the major sources of PAH compounds in the Gy?r atmosphere were fossil fuel combustion and vehicle emissions.     

Indoor Polycyclic Aromatic Hydrocarbon Concentration in Central India

The indoor burning of different materials like fuels, incense, mosquito coil, candles etc. results in generation of polycyclic aromatic hydrocarbons (PAHs) in an uncontrolled manner. The PAH, i.e., Benzo(a)pyrene (BaP) is considered as most toxic or carcinogenic and the toxicity of other PAHs is related to this compound. Therefore, the concentration and emission fluxes of polycyclic aromatic hydrocarbons (PAHs) emitted during burning of commonly used indoor materials, i.e., 15 fuels (i.e., biomass (BM), coal (C), cow dung (CD), kerosene (K)), 4 incense (IS) and mosquito coil (MC) in Raipur district, Chhattisgarh, central India is described. The samples were taken in September 2013 in indoor environments and respective smoke emitted were collected using high volume United State of America (USA) air sampler on quartz fiber filters. The concentration of total 13 PAHs (∑PAH₁₃) (i.e., phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)-pyrene, dibenz(ah)anthracene, benzo(ghi) perylene, indeno1,2,3-(cd)pyrene, and coronene) in particulate matter (PM₁₀) in the indoor air during burning of the fuels, IS and MC materials ranged from 367–92052 ng m^?3, 4089–14047 ng m^?3, and 66–103 ng m^?3 with mean values of 7767 ± 11809 ng m^?3, 9977 ± 4137 ng m^?3, and 74 ± 20 ng m^?3, respectively. The mean concentration of the ∑PAH₁₃ present in indoor environment is much higher than the WHO limit value of 1.0 ng m^?3. The sources and toxicities of PAHs are discussed.     

Determination of Polycyclic Aromatic Hydrocarbons in Water- and Gin-Based Tea Infusions of Selected Tea Brands in Nigeria

The concentrations of the 16 priority polycyclic aromatic hydrocarbons (PAHs) in tea infusions made of water and local gin (alcohol) were investigated with a view to providing information on the profiles and health hazards associated with these two common Nigerian methods for tea consumption. The water-based tea infusion was prepared by submerging 4 g of tea in boiling water and allowing it to stand for 15 min, while the gin-based infusion was simply prepared by submerging 4 g of tea in gin at room temperature and allowing it to stand for 15 min. The concentrations of the ∑16 PAHs in the infusions were measured by using gas chromatography equipped with a flame ionization detector (GC-FID) after ultrasound-assisted extraction and clean-up. The concentrations of the ∑16 PAHs ranged from 24.9–623.4 μg kg^?1 with a mean value of 177 μg kg^?1 and 36.8–438.3 μg kg^?1 with a mean of 189 μg kg^?1 for water- and local gin-based infusions, respectively. The concentration of the ∑16 PAHs in the water- and local gin-based infusions of these teas were high when compared with levels reported in the literature for tea infusions. The local gin-based infusions had a higher mean level of the ∑16 PAHs than the water-based infusions. Four- and five-ring PAH compounds were dominant in these tea infusions.     

Gas-Particle Partitioning of PAHs In The Urban Air of Dalian,China: Measurements and Assessments

To evaluate the gas-particle partitioning behavior of polycyclic aromatic hydrocarbons (PAHs) in the urban air of Dalian, China, both gas phase and particle phase ambient air were monitored with active high-volume sampler from November 2009 to October 2010. The average total concentration of 16 US EPA priority monitoring PAHs (particle + gas) (∑PAHs) was 112 ng m^?3 and the most abundant PAH was Phenanthrene. ∑PAHs and the gas-particle partitioning coefficients (K _p) of PAHs displayed seasonal variation in the order of winter > autumn > spring > summer. ∑PAHs was much higher during the heating period than non heating period. ∑PAHs in gas phase were all higher than those in particle phase in the four seasons. The PAHs sources identification was attempted using diagnostic ratios. The relationship between the concentration of PAHs in the air and meteorology parameters were analyzed using SPSS packages. The concentrations of PAHs in the air decreased with the increase of ambient temperature, and increased with the increase of atmospheric pressure. The gas-particle distribution was examined through several different approaches such as the relationship of logK _p with the ambient temperature, with the logarithm of the sub-cooled vapor pressure (logP _L ⁰), and the octanol-air partitioning coefficient (logK _oa) of PAHs. The slopes obtained from regressing logK _p vs. logP _L ⁰ was ?0.687～?0.821 in heating periods, which was in the range between ?0.6 and ?1, indicating the partitioning of PAHs to particle phase in the urban air of Dalian was absorption as well as for adsorption mechanism. However, the average slope value was ?0.502 in the non heating periods, which was shallower than -0.60, indicating that the absorption mechanisms contributed more to the partitioning process. The exposure risk of PAHs was evaluated with four methods, the results of which indicated that the quality of the urban air of Dalian was better.     

Personal Exposure of Children to Particle-Associated Polycyclic Aromatic Hydrocarbons in Tianjin,China

Polycyclic aromatic hydrocarbons (PAHs) associated with fine particles are harmful to human health, particularly to children, who are most vulnerable. To evaluate the respiratory exposure of children to particle-associated PAHs properly, personal air sampling near breathing zone of 36 schoolchildren were conducted in Tianjin, China. Sixteen priority PAHs designated by the United States Environmental Protection Agency were measured using GC-MS. The average concentrations of personal exposure to ∑₁₆PAH were 27.31 ± 3.91 ng/m³ in summer and 58.18 ± 24.68 ng/m³ in winter. Moreover, PAH profiles were studied and the results showed NAP, BbF, and IPY were the most abundant PAHs. Five rings PAH species made up the largest proportion, accounting for 25.7% in summer and 32.6% in winter. Diagnostic ratios and principal component analysis indicated combustion activities were the major source for children exposure to particle-associated PAHs in this study. According to the risk assessment results, the inhalation exposure risk for children were higher than the acceptable risk level of 10–⁶, indicating the health issues of children should be paid more attention. On the basis of sensitivity analysis results, further research should be done to improve the inhalation cancer slope factor of BaP and the concentration distribution of PAHs in order to improve the accuracy of the health risk assessment.     

Seasonal and Spatial Variation of Polycyclic Aromatic Hydrocarbons in Vapor-Phase and PM2.5 in Southern California Urban and Rural Communities

Fifteen priority polycyclic aromatic hydrocarbons (PAHs) were measured in two rural communities (Atascadero and Lompoc) located several hundred km northwest of Los Angeles and in four urban communities 40–100 km downwind of Los Angeles (San Dimas, Upland, Mira Loma, and Riverside), during all seasons, from May 2001 to July 2002. PM_2.5 and vapor-phase PAHs were collected, on prebaked quartz fiber filters and PUF-XAD-4 resin, respectively, at 113 LPM, during 24 h periods, every eighth day, and quantified by HPLC-Fluorescence. At all sites vapor-phase PAHs contained > 99.9% of the total PAH mass and were dominated by naphthalene (NAP), which varied from about 60 ng m ^{? 3} in Lompoc, a community with light traffic, to ～580 ng m ^{? 3} in Riverside, a community traversed by ～200,000 vehicles day^{? 1}. During summer pollution episodes in urban sites, NAP concentrations reached 7–30 times annual averages. Except for summer episodes, concentrations of low MW PAHs showed small seasonal variations (～2 times higher in winter). Similar concentrations of particle-phase PAHs were observed at all sites except for Lompoc. Benzo[ghi]perylene (BGP), a marker of gasoline exhaust emissions, showed the highest concentration among particle-phase PAHs, varying from 23.3 pg m^?3 in Lompoc to 193 pg m^?3 in Mira Loma. Benzo[a]pyrene and indeno[1,2,3-cd]pyrene, found exclusively in the particle phase, were much higher in urban sites (～40–100 pg m^?3), than in Lompoc (～12 pg m^?3). Winter particle-phase PAHs were 2 to 14 times higher than summer levels. Particle-phase PAHs were negatively correlated with mean air temperature in urban sites (r = ?0.50 to ?0.75), probably resulting from surface inversions occurring during winter. The data suggest that in Southern California vehicular exhaust emissions are a major contributor to particle-phase PAHs.     

Seasonal Influence on Vapor-and Particle-Phase Polycyclic Aromatic Hydrocarbon Concentrations in School Communities Located in Southern California

Ambient concentrations of 15 vapor-and particle-phase (PM _2.5 ) polycyclic aromatic hydrocarbons (PAHs), listed by the US EPA as priority pollutants, were measured between July 2002 and November 2003 in six Southern California communities participating in a multi-year chronic respiratory health study of schoolchildren. The communities were geographically distributed over two hundred kilometers, extending from Long Beach in coastal Los Angeles, to high mountain areas to the north and west of the Los Angeles basin, and south into Eastern San Diego County. Seasonal and spatial variation in the atmospheric concentrations of PAHs is of interest because this class of compounds includes potent mutagens, carcinogens, and species capable of generating reactive oxygen species (ROS) that may lead to oxidative stress. Naphthalene accounted for 95% of the total PAH mass; annual averages ranged from 89 to 142 ng m ^{? 3} . Benzo[ghi]perylene (BGP) and the pro-carcinogen benzo[a]pyrene (BAP), present almost exclusively in the particle-phase, ranged respectively from 38 to 231 pg m ^?3 and 75 and 111 pg m ^{? 3} , with the highest values observed in Long Beach, a community with a high volume of seaport-related activities, and Lancaster, a commuter dormitory community. A considerable increase in the particle-phase PAH concentration, relative to the vapor-phase, was observed as ambient temperature decreased. Cold/hot season ratios for PAHs in PM _2.5 averaged 5.7, reaching 54 at Long Beach. The presented data underscore the importance of seasonal variations on atmospheric PAH concentrations. These observations are relevant to future interpretation and analysis of community-scale human health effects research.     

Ecological and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Water from Middle and Lower Reaches of the Yellow River

In surface water from the middle and lower reaches of the Yellow River, total equivalent concentrations of 16 US EPA priority PAHs were calculated based on the measured concentrations. Ecological risk assessment approaches, including hazard quotient and overlapping areas of probability density curves, were performed to evaluate the combined ecological risks of PAHs to the aquatic organisms. The result from hazard quotient indicated that risk quotient of mollusks and zooplankton surpassed 0.1, suggesting potential risks. The potentially affected fractions of PAHs obtained from overlapping areas of probability density curve varied from 11.2% (dry season) to 5.1% (rainy season), which implied that PAHs had been posing pressures on the ecosystem. Health risk based on the incremental lifetime risk for PAHs was conducted to evaluate human cancer risk and noncarcinogenic hazard in the studied area. The results indicated that health risks mainly came from ingestion exposure pathway. The total cancer risks were in the range of 10^?8 to 10^?7, lower than the baseline value of acceptable risk (10^?6). Moreover, non-carcinogenic hazard indices of PAHs ranging from 10^?6 to 10^?5 were much lower than the threshold values (1.0). These results indicated that the water from middle and lower reaches of Yellow River might pose no health risk on local residents as a source of drinking water.     

Analysis of Polycyclic Aromatic Hydrocarbon,Toxic Equivalency Factor and Related Carcinogenic Potencies in Roadside Soil within a Developing City of Northern India

Preliminary analysis was performed to assess contamination levels in roadside soils, distribution behavior and human exposure with Polycyclic Aromatic Hydrocarbons (PAHs) during summer, winter, rainy, and autumn during 2013 in one of the developing cities of northern India. The concentration of PAHs was measured at ten different locations (at 1, 2, and 3 m) from roadside soil. Recovery range was 30% and 80% with lower value corresponding to the lower molecular weight PAHs compound. Identification and quantification of PAHs was done by GC-FID. Average PAHs concentration (city average) was found to be 16.53, 4.04, 17.49, and 7.82 μg g^?1, during summer, winter, autumn, and the rainy seasons, respectively. Average concentration of low and high carcinogenic PAHs during summer, winter, autumn, and rainy was 5.1 and 31.29, 2.1 and 6.4, 4.74 and 35.08, 3.97 and 12.77μg g^?1_, respectively. The average ratio of low and high carcinogenic PAHs was found to be 1:6, 1:3, 1:7.6, and 1:3.21 during summer, winter, autumn, and the rainy seasons at most intercepts. Dib(ah)A and B(a)P were the two individual PAHs found in highest concentration during summer, winter, and the rainy seasons, whereas B(a)P and IP were individual PAHs found in highest concentration during autumn. It was also analyzed that high carcinogenic PAHs concentration was quite higher (around 85%) in comparison to low carcinogenic PAHs (around 15%) at most intercepts. This article also deals with the behavior of PAHs at places of average/high population and traffic density intercepts. Five-ringed PAHs were in highest concentration at all intercepts and seasons. Two-tailed T test was applied for authenticity of the data and results. Toxic equivalency factor of B(a)P and Dib(ah)A was maximum as compared to other PAHs.     

Polychlorinated Biphenyls in Sediments from Sicilian Coastal Area (Scoglitti) using Automated Soxhlet,GC-MS,and Principal Component Analysis

A methodology for the PAHs and PCBs congener determination in sediment samples has been revised. We determined the distributions of PAHs and PCBs in the superficial sediments of the Scoglitti (Italy) coastal area to provide data for comparison with other marine systems and to hypothesize the sources. Extraction yield, for PCB, was never less than 60% in most cases, while for PAHs, utilizing perdeuterated surrogate standard (benz[a]anthracene-d₁₂ and anthracene-d₁₀) was never less than 72%. The total concentration of the 16 PAHs investigated, expressed as the sum of concentrations, ∑PAHs, varied from 1–5087 μg/kg of dry matrix, while the ∑ PCBs ranged from detection limit to 36 μg/kg of dry matrix. Linear relationships were found between PAHs concentration and organic matter percentages (R² = 0.60) and water content and organic matter percentages (R² = 0.87). Isomeric ratios were used for discriminating between pyrolitic and petroleum origin. The principal component analysis (PCA) has been conduced to discriminate the different sampling sites in internal or external harbor area.     

Monitoring and Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmosphere of Alexandria City,Egypt

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in the total suspended particulate (TSP) were measured simultaneously between January 30, 2015 and February 11, 2016 at urban, suburb, and rural sites at Alexandria City, Egypt, using pesticide samplers. Samples were extracted and analyzed using chromatography–mass spectrometric (GC–MS). There was a significant difference in concentrations between the three sites, and between particle- and vapor-phases. Mean total PAH concentrations were 502.48, 322.57, and 417.23 ng m^?3 for the urban, the rural, and the suburban sites in particulate-phase and were 723.49, 402.26, and 543.15 for the same sites in vapor-phase, respectively. At the three sites, the most abundant compounds determined were Benzo[k]fluoranthene (BkF), followed by Benzo[a]pyrene (BaP) and Indeno [1,2,3-cd] pyrene (IcdP). These high molecular weight compounds are carcinogenic and known to originate mainly from vehicular emissions. The diagnostic ratios indicated PAHs in urban and suburban sites were predominantly from gasoline and diesel engines, while that in rural site was from biomass burning. Characterization of the emission sources was further substantiated by significant correlation between individual PAH species.     

Priority Polycyclic Aromatic Hydrocarbons (PAHs): Distribution,Possible Sources and Toxicity Equivalency in Urban Drains

Wastewater from urban areas constitutes one of the major sources of pollutants contributed to aquatic ecosystem. This study was carried out to elucidate the occurrence and possible source of US Environmental Protection Agency identified 16 priority polycyclic aromatic hydrocarbons (PAHs) in water and sediments from the urban wastewater drains in Delhi, India. A total 60 samples (water and sediment) collected during year 2011–2012, and analyzed the following USEPA methods. Water and sediment samples were extracted using liquid-liquid and ultrasonication techniques, respectively. Glass column chromatography with activated silica was used for sample extracts clean-up, followed by quantification on HPLC equipped with diode array detector at 254 nm wavelength using mixture of acetonitrule and water as mobile phase. Concentrations of total 16 PAHs (∑16PAHs) in all drain water samples ranged from 0.29–35.22 μg/L (mean ± SD, 10.83 ± 10.66 μg/L), predominated by two- and three -ring PAHs. The ∑16PAHs concentrations in all collected sediments ranged between 220–19321 μg/kg (mean±SD, 5574 ± 6820 μg/kg) dry weights. High molecular weight PAHs (≥4-ring PAHs) were dominant in sediment samples. Benzo(a)pyrene equivalent (BaPeq), a relative carcinogenic potential to the corresponding PAHs to BaP was estimated and presented. A selected number of concentration ratios of specific PAHs compounds were calculated and used to diagnose the possible sources of PAHs contamination. The diagnostic ratios reflected pyrogenic input from gasoline or diesel powered vehicular emissions as the major source of PAHs. The levels of PAHs observed in water and sediments were compared with similar studies undertaken in other regions of the world.     

PAHs and Mutagenicity of Inhalable and Respirable Diesel Particulate Matter in Santiago,Chile

Delayed human effects such as cancer could be a consequence of chronic exposure, over long periods of time, to inhalable (PM₁₀) and respirable (PM_2.5) particles containing environmental carcinogen mixtures. Air pollution in Santiago, Chile, is a major public health problem due to the high levels of regulated pollutants such as PM₁₀, CO, and ozone. In this work, we studied the levels of polycyclic aromatic hydrocarbons (PAHs) onto PM₁₀ and PM_2.5 collected in diesel revision plants, in an urban area with a high flow of buses and trucks and in a rural area not exposed to diesel emissions. The PM₁₀ average levels in diesel emission plants were higher than the Chilean PM₁₀ standard and higher than those found in the urban and rural areas. In the urban area the PM₁₀ average levels were lower than the Chilean PM₁₀ standard, although some 24 h levels surpassed the levels established to decree preemergency or emergency and in some cases were higher than the levels reported by all the official monitoring stations. The levels of total PAHs onto PM₁₀ were higher in the diesel plants than in the urban area and rural area, but the levels of six carcinogenic PAHs were similar in the diesel plants to those found in the urban area. Organic extracts from PM₁₀ collected in diesel plants in Salmonella typhimurium TA98 in the presence and in the absence of an S9 activation system were significantly higher than in the urban area and rural area. Mutagenic activity with and without S9 in diesel plants and the urban area showed that indirect (PAHs) and direct (nitro-PAHs) mutagenic compounds are present in organic extracts from PM₁₀. In conclusion, these results showed that in Santiago diesel emission particles were highly mutagenic and contain carcinogenic PAHs. This might represent a risk for long-term respiratory effects in Santiago's inhabitants.     

Polycyclic Aromatic Hydrocarbons,Heavy Metals,and Genotoxicity of the Suburban Soils from Guangzhou,China

During the past few decades, urban and suburban developments have grown at unprecedented rates and extents with unknown consequences for ecosystem function. The problem of soil pollution as a result of the accelerating development of Guangzhou in China is becoming great concerns. In the present study, gas chromatograph coupled mass spectrometry (GC-MS), inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were employed to determine the 16 US Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) and the heavy metals (As, Cr, Cu, Pb, Cd, Hg, and Se) of soils collected from suburban areas of Guangzhou. The genotoxicity of these soils was screened with micronucleus (MN) assay in Vicia faba root cells. The concentrations of the pollutants in the soils were (dried weight): ΣPAHs (230.6–1263 ng·g^?1), As (2282.6–36064 μg·kg^?1), Cr (7109–64699 μg·kg^?1), Cu (7047–56388 μg·kg^?1), Pb (9675.9–93739 μg·kg^?1), Cd (68.5–847.3 μg·kg^?1), Hg (85.4–549.2 μg·kg^?1), and Se (219.2–968 μg·kg^?1), which fell in the moderately polluted range. However, six out of nine soil-exposed groups had a significant increases of MN frequencies observed in the V. faba root cells compared with the negative group (P < 0.05, P < 0.01), indicating that they had potential genotoxic risks. Bringing together the chemical analyses with the biological effects observed in this study, the genotoxic response could at a certain degree be explained by both the soil PAHs and heavy metals. Our results suggested that apart from chemical analysis, bioassays like the MN assay of V. faba root cells should also be included in a battery of tests to assess the eco-environmental risks of urban and/or urbanization in the developing areas on the soils.     

Characterization and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Surface Water from Liaohe River,Northeast China

ABSTRACT

In this study, the characteristics, probable source, and potential carcinogenic risk of 16 polycyclic aromatic hydrocarbons (PAHs) in surface water of the Liaohe River were investigated. Twelve sampling points were selected, and water samples were collected in both dry and flood periods of 2011. Sample analysis indicated that the concentration of total PAHs varied from 840.50 ng/L to 4274.73 ng/L in the flood period, and from 387.76 ng/L to 1997.83 ng/L in the dry period. The representative PAHs in the flood period were benz[a]anthracene (Baa), naphthalene (Nap), and chrysene (Chr), whereas Phenanthrene (Phe), fluoranthene (Flu), and pyrene (Pyr) were the representative PAHs in the dry period. The compositional pattern of PAHs indicated that four-ring PAHs were predominant in the flood period, whereas three-ring and four-ring PAHs dominated in the dry period. The different PAH congener ratios indicated that PAHs in surface water of the Liaohe River mainly originated from a mixed source in the flood period, and from combustion in the dry period. Based on the methods of Incremental Lifetime Cancer Risk (ILCR) and the benzo[a]pyrene toxic equivalent (TEQ), the potential cancer risk was quantitatively assessed, and the results suggested that there was a potential cancer risk in surface water of the Liaohe River and more attentions must be paid to the PAHs contamination. The cancer risk in the teenager group was the most, followed by the children group, adult group, and infant group, and toddler group was the least.     

Source Apportionment and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Sediments from Upper Reach of Huaihe River,China

Fifteen priority PAHs in 16 sediments from upper reach of Huaihe River collected in 2007 were measured. Source apportionment derived from PCA/MLR indicated that the highest contribution to ΣPAHs was from biomass burning (34.1%), followed by coal combustion (29.7%), vehicular emission (25.8%), and coke oven origin (10.4%). Risk assessment for each identified source was quantitatively calculated by combining the benzo[a]pyrene equivalent (BaPE) with estimated source contribution. The results showed that coal combustion posed the highest toxic risk, with BaPE value of 13.1 ng g^?1 dw, and the BaPE values for biomass burning, vehicular emission and coke oven were 5.6 ng g^?1 dw, 7.8 ng g^?1 dw, and 4.1 ng g^?1 dw, respectively. The distributions of contribution for total PAHs burden and BaPE of each identified source showed similar pattern among different sampling sites.     

Polycyclic Aromatic Hydrocarbons Determination in Grilled Beef and Chicken

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) are principally formed as a result of thermal treatment of food, especially grilling or barbecuing. In the present study, two types of Iranian popular grilled beef and chicken dishes (kebab) were analyzed for toxic PAHs, i.e., naphthalene, fluoranthene, phenanthtrene, anthracene, pyrene, and benzo(a)pyrene applying GC/MS. The differences in PAHs concentrations among grilled beef and chicken (kebab koobide and juje kebab) were found to be significant (p < 0.05), ranging from 0.29 to 21.95 ng·g^?1. Benzo(a)pyrene was found in nearly all samples; the maximum concentration of total PAHs was 21.95 ng·g^?1 found in grilled beef (koobide Khalij fars) and the lowest was 0.29 ng·g^?1 in grilled chicken (juje kebab) of Sahel restaurant.     

Photoluminescence properties and thermal stability of samarium-doped barium phosphate phosphors

In this paper, Sm³⁺-doped Ca₆BaP₄O₁₇ phosphors were synthesized via a conventional solid-state reaction method. Orange-red emission was observed from these phosphors under near-ultraviolet (UV) excitation at 405 nm. The luminescence properties of the obtained phosphors were characterized. The Ca₆BaP₄O₁₇:Sm³⁺ phosphor can be efficiently excited by near-UV and blue light, and their emission spectrum consists of three emission peaks, at 567, 602, and 650 nm, respectively. The thermal stability of Ca₆BaP₄O₁₇:Sm³⁺ phosphors was investigated systematically and corresponding mechanisms were proposed. Based on the results, the as-prepared Ca₆BaP₄O₁₇:Sm³⁺ phosphors are promising orange-red-emitting phosphors for near-UV-based white light-emitting diodes.     

Levels,Sources, and Risk Assessment of Polychlorinated Biphenyls (PCBs) in Soils from Industrial Areas: A Case Study from Saudi Arabia

ABSTRACT

The objective of this study was to assess the pollution levels, sources, and human health risk of polychlorinated biphenyls (PCBs) in soils of industrial areas of the central and eastern regions of Saudi Arabia. Therefore, the surface soil samples from industrial areas (cement kiln, oil refinery, electric power plant, steel industry, and desalination plant) were collected and analyzed by High-Resolution Gas Chromatography-Mass Spectrometry/Mass Spectrometry-Time of Flight (HRGC-MS/MS-TOF) to quantify the levels of 26 PCBs (including 12 dioxin-like PCBs and 14 indicator-PCBs). The investigated 26 PCBs were detected in all soil samples. The total PCBs concentration (from tri-CBs to hepta-CBs) ranged from 171 to 4892 pg g^?1 with an average of 1369 pg g^?1 in soils of the central region and of 142–1231 pg g^?1 with an average of 302 in soils of the eastern region, showing higher values at cement factory and/or oil refinery sites. Overall, the indicator-PCBs were the main congeners and contributed dominantly to the total mass of PCBs in comparison with the dioxin-like PCB congeners, with the most abundant for PCB-180 in the soil samples of the central region. Among individual dioxin-like PCBs, PCB-126 had the highest average value of the toxicity equivalence (TEQ). The TEQ values of ∑12dioxin-like PCBs did not exceed the Canadian soil quality guidelines of dioxin (4 pg TEQ g^?1). Based on human health risk assessment via ingestion, dermal contact, and inhalation, low adverse effects of PCBs could be expected as indicated by lower values of cancer risk (≤10^?6). The principal component analysis indicated that there is a different source of PCBs with similar or different PCB profiles.