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.     

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.     

Polycyclic Aromatic Hydrocarbons in Residential Soils from an Indian City near Power Plants Area and Assessment of Health Risk for Human Population

This article deals with the distribution, composition profiles, and possible sources of sixteen priority polycyclic aromatic hydrocarbons (PAHs) in residential soils from Korba district in Chhattisgarh State, India. Sixteen priority PAHs in soils were analyzed after ultrasonic extraction, silica gel column chromatographic cleanup, and quantitation was performed using HPLC-DAD. The concentrations of ∑16PAHs were within acceptable limits of soil quality guidelines and the study area got classified as weakly contaminated. The concentration of probable human carcinogenic PAHs in soils accounted for 10% of ∑16PAHs. The concentration of Benzo(a)Pyrene (BaP) accounted 1% to total PAHs. Benzo(a)pyrene Toxicity Equivalency (BaP_TEQ) for 16 PAHs was 30 ± 12 μg BaP_TEQ kg^?1. The composition profiles and molecular ratios of PAHs suggested mixed pyrogenic sources of PAHs from combustion of coal, wood, and vehicular exhaust emissions. Human health risk was assessed by calculating the lifetime average daily dose (LADD) and incremental life time cancer risk (ILCR) for human adults and children. Estimated ILCR was within safe limit (10^?6?10^?5), indicating low risk to human population. Potential risk to contaminated ground water from leaching of carcinogenic PAHs was assessed by estimating the Index of Additive Cancer Risk (IACR).     

Source Allocation of Aliphatic and Polycyclic Aromatic Hydrocarbons in Particulate-Phase (PM10) in the City of Valdivia,Chile

The concentration and signature of n-alkanes (n-C₁₀ to n-C₃₃) and 18 PAHs were determined in air filters across a year period (2010) in an urban area of the city of Valdivia, Chile. Filter samples were extracted using sohxlet apparatus and analyzed by GC-MS techniques. Concentrations of total hydrocarbons ranged from 45–352 ng.m^?3 and total PAHs ranged from 2.93–78.01 ng.m^?3. Concentrations of hydrocarbons during the summer were high (288–352 ng.m^-3) and reduced when the autumn began (45–79 ng.m^?3) to then increase almost linearly to the next summer. The drop in concentration was attributed in part to the significant reduction of traffic when summer ends as tourists leave the city (about 9–15% of the total cars circulating). Results from the chemometric technique of Polytopic Vector Analysis (PVA) indicated three main sources for the alkanes: biogenic (terrestrial plants), signatures of oil combustion, and an unconfirmed source which is thought to come from non specific organic matter degradation. Total PAHs correlated well with total particulate matter with a R² = 0.94. Levels of PAHs in the atmosphere were higher during the winter (6.85–78.01 ng.m^?3) period than the rest of the year (2.93–36.30 ng.m^?3). PVA results indicate three key sources of PAHs and two of those sources derived from oil combustion and biomass burning.     

Levels of Some Persistent Organic Pollutants (PCBs and PAHs) in Jordanian Oil Shale Ash after Direct Heating at Different Temperature Ranges

The levels of 13 polycyclic aromatic hydrocarbons (PAHs) and 12 polychlorinated biphenyls (PCBs) were studied in oil shale ash samples gathered after heating oil shale samples collected from major deposit sites in Jordan. All analyses were carried out using GC/MS instrument. The results showed that the total concentration of the studied polycyclic aromatic hydrocarbon (PAHs) was the highest (75.99–317.53 μg /kg) at the lowest temperature range (200–400°C) and it decreased as the temperature increased. For the heating temperature range 400–600°C the concentrations were all decreased to below the limit of quantification while none of the samples contained any of the studied PAHs at the highest temperature range 600–800°C. While all the analyzed samples did not contain any of the studied 13 compounds of PCBs at different temperature ranges.

Recoveries of PAHs and PCBs were found between 82–106% and 91–114%, respectively. Precision of the analytical method for both PAHs and PCBs, calculated as relative standard deviation (RSD), ranged from 0.95–7.08% and 0.78–9.03%, respectively. The limit of detection values for PAHs and PCBs were between 0.006–0.070 μg/kg and 0.149–0.330 μg/kg, respectively.

The total estimated cancer risks of exposure to PAHs in the soil samples were ranged from 9.13 × 10^?7 to 2.15 × 10^?6. By multiplying these numbers of cancer risks of exposure to oil shale ash sample-PAHs by 10⁶, it is possible to determine the maximum theoretical number of cancer cases per million of people. The maximum estimated cancer risks cases determined in this study (2 out of 1 million) are well within the acceptable range of excess cancer risk specified by the US Environmental Protection Agency.     

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.     

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.     

Residue Levels,Profiles, Emission Source and Daily Intake of Polycyclic Aromatic Hydrocarbons Based on Smoked Fish Consumption,An Egyptian Pilot Study

Residue levels and spectrum of polycyclic aromatic hydrocarbons (PAHs) were determined in smoked fish, and canned smoked fish, collected from grocery shops from Cairo, Giza, Menoufya, and Ismailia governorates, Egypt. Residues of PAHs were monitored using gas liquid chromatography, equipped with a flame ionization detector. The concentrations of ∑13 PAHs in the smoked fish and the canned smoked fish ranged from 36.06–547.1 μg/kg, respectively. Benzo(a)pyrene was not detected in smoked canned fish, while its mean residues in smoked fish amounted to 1.1 μg/kg, corresponding to one fifth of the maximum tolerable limit of 5 μg/kg established by EU. The congeners profile showed that the sources of PAHs in the two brands of smoked fish are mainly petrogenic. Based on smoked fish the daily intake of 13 PAHs and benzo(a)pyrene were 45.59 μg/day and 0.092 μg/day, respectively, while for canned smoked fish the intake was fifteen times lower (3 μg/day), and the intake of benzo(a) pyrene is zero μg/day. Results showed that the consumption of smoked fish would pause some risk to consumers; meanwhile canned smoked fish showed no risk to Egyptian consumers.     

Concentrations and Source Identification of Polycyclic Aromatic Hydrocarbons (PAHs) in Mangrove Sediments from North of Persian Gulf

The concentrations of 16 Environmental Protection Agency (EPA) priority polyaromatic hydrocarbons (PAHs) were quantified in surface sediments from Hormozgan Province mangroves, south of Iran in dry and wet seasons. Sampling stations were selected in Laft and Khamir mangroves with international importance. Polyaromatic hydrocarbons varied from 75.24 ± 11.24 to 581.94 ± 637.39 ng/g dry weight basis. Pollution sources and their contribution for polyaromatic hydrocarbons pollution in sediments of Hormozgan mangroves were appointed based on molecular ratios and statistical methods, including principal components analysis (PCA) and multiple linear regression/principal components analysis (PCA/MLR) tests. Both of pyrogenic and petrogenic sources contributed in detected concentrations of PAHs. Contribution percentages of pyrogenic and petrogenic origins were estimated at 73.20 and 26.79%, respectively. Temporal variations showed that sediments contained higher levels of ∑PAHs in wet season than dry time. However, the mean detected ∑PAHs was lower than international quality guidelines; the high concentration of PAHs was found in Laft mangrove, suggesting the presence of PAH polluted localized area.     

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.     

The PAH and Nitro-PAH Concentration Profiles in Size-Segregated Urban Particulate Matter and Soil in Traffic-Related Sites in Catania,Italy

Polycyclic aromatic hydrocarbons (PAHs) and nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) were identified from both air particulate matter and soils. For air sampling, a six-stage cascade impactor was situated in an urban area (Catania, Italy) that is recognized for its high traffic volume. The soil samples were collected every 1.5 km from under the grass by the side of the median of a Catania road along its full length (8.2 km). HPLC in electrochemical-fluorescence detection mode was used for selective separation, identification and quantification of analytes in air and soil samples, providing both good selectivity and sensitivity. The seasonal trends, effects of urban traffic, and source profiles are discussed herein. Higher PM₁₀ concentrations were observed for summer (43 μg m^?3) in comparison to winter (24 μg m^?3). Conversely, the PAHs contained in PM₁₀ were higher in winter (0.48 ng m^?3 for fluoranthene) than in summer (0.14 ng m^?3 for fluoranthene). Analysis of the size-segregated urban particulate matter showed that the amount of PM_0.5 (stage 6) was always higher than the amount of other particles (stages 1–5). Furthermore, the PM_0.5 was always higher in summer (about 40%, m/m) than in winter (about 30%, m/m). Finally, the amounts of PAH and nitro-PAH in PM_0.5 (stage 6) were always higher, by a maximum of one order of magnitude, than that of other particles (stages 1–5). This result is crucial because ultrafine particles have a tendency to move into the blood through the alveolar epithelial barrier. Moreover, the air and soil pollution levels agree with those found in other cities with similar levels of pollution. Supplemental materials are available for this article. Go to the publisher's online edition of Polycyclic Aromatic Compounds to view the supplemental file.     

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.     

Determination of Drying Characteristics of Timber by Using Artificial Neural Networks and Mathematical Models

In this research, poplar and pine timbers have been dried in heat pump dryer functioning on the basis of 24-h operation. The change in weight in all of the timbers was followed in the drying chamber and drying stopped when the desired weight was achieved. Initial moisture content of the poplar timbers was 1.28 kg water/kg dry matter, and the moisture content was reduced to 0.15 kg water/kg dry matter moisture content in 70 h; the moisture content of the pine timbers, which was 0.60 kg water/kg dry matter, was reduced to the same amount in 50 h. Drying air temperature, relative humidity, and stack weight were measured and collected during drying and saved on a computer and analyzed afterwards. The moisture ratios were analyzed with Statgraphic computer program by using semitheoretical models and empirical values. Correlation and standard error of estimation (SEE) and R ² values were achieved.     

Determination of Carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs), Aflatoxins,and Nitrosamines in Processed Fish from the Winam Gulf Area of Kenya and Estimated Potential Exposure in Human

PAHs, aflatoxins and nitrosamines were analyzed in fish samples obtained from various markets and locations within the Winam Gulf area and processed by various methods often used in Kenya. The mean concentrations of total PAHs (TPAHs) in the smoked, charcoal-grilled and fresh tilapia muscle samples ranged from 22.27–44.58, 20.36–28.51, and 11.43–16.53 μg/kg wet weight, respectively. The concentrations of individual PAHs decreased in the order smoked>charcoal-grilled>fresh fish. Of the USEPA 16 PAHs, benzo(a)pyrene, dibenzo(a,h)anthracene, indeno(1,2,3-cd)pyrene, and benzo(g,h,i)perylene were not detected in all samples analyzed. Fluoranthene, acenaphthene, anthracene, phenanthrene, and acenaphthylene were not detected in fresh tilapia muscles but were generated in significant amounts on the samples during smoking and charcoal-grilling. The risk of exposure to human was estimated to be 0.67 μg/day through consumption of tilapia. The TPAHs levels in fresh fish, smoked and grilled tilapia were higher than the maximum allowable concentrations as per the WHO standards. Aflatoxins were found to be generated in sun-dried Dagaa during handling and storage with total mean concentrations ranging from 0.33–1.58 μg/kg wet weight but none were detected in the fresh samples. The daily intake of aflatoxins through consumption of Dagaa was estimated to be 0.0079 μg/day during the rainy season when the drying process is less efficient. None of the nitrosamines were detected in both fresh and the deep-fried tilapia muscle samples (frying temperatures ranging from 110–170°C) after exposure to nitrites and nitrates in water, in concentrations ranging up to 10 μg/L (NO₂^?) and up to 160 μg/L (NO₃^?).     

Emission characteristics of PAHs, benzene and phenol group hydrocarbons in O2/RFG waste incineration processes

This study applies the oxygen/recycled flue gas (O₂/RFG) combustion technology for waste incineration in a laboratory-scale fluidized bed incinerator to investigate the effects of different RFG percentages and O₂ concentrations on the emission characteristics of organic pollutants (PAHs, phenol and benzene hydrocarbons). Experimental results show that most PAHs with high-ring structures were present in solid-phase and most low-ring PAHs were present in gas-phase. The major compounds of benzene and phenol hydrocarbons were benzene, toluene, trichlorobenzene and 2,4-dinitrophenol, phenol, dichlorophenol, respectively. As the O₂ concentration in feed gas was increased from 21% to 40%, the emissions of solid- and gas-phase PAHs and phenol compounds were decreased but not for benzene compounds. Increasing RFG percentages would decrease the emissions of gas-phase PAHs, benzene and phenol compounds, but increased those of solid-phase pollutants. The best operating conditions of such O₂/RFG combustion system to reduce the emissions of PAHs and phenol compounds were 40% O₂, 35% RFG, and that for benzene compounds was 21% O₂, 75% RFG. Comparing with conventional air combustion system, the best diminution efficiencies of PAHs, benzene and phenol compounds at such O₂/RFG conditions were 59.54%, 70.97% and 52.60%, respectively. With proper feed gas compositions and RFG percentages, the combustion efficiency and destruction efficiency of organic pollutants can be improved by this O₂/RFG combustion technology.     

The Effect of Local Cooking Methods on Polycyclic Aromatic Hydrocarbons (PAHs) Contents in Beef,Goat Meat,and Pork as Potential Sources of Human Exposure in Kisumu City,Kenya

Roasted meat is known to be a major source of human exposure to PAHs. The contribution of direct-heat charcoal-roasted, electric- oven grilled, and shallow-pan fried meat to human exposure in Kisumu City was not known although the three modes of cooking meat are very prevalent. This study analyzed the concentrations of the PAHs in raw beef, goat meat, and pork, investigated the effect of direct-heat charcoal roasting, electric-oven grilling, and shallow-pan frying on these concentrations, and compared their concentration levels with international standards for foods in order to assess the potential risks to consumers. Samples were taken from three popular meat-roasting hotels within Kisumu City, Kenya. Extraction of PAHs was done using liquid-liquid partition after saponification with alcoholic potassium hydroxide followed by clean-up on a silica gel column and final analysis by gas chromatography-mass spectrometry (GC-MS). Roasting and shallow-pan frying introduced new PAHs and significantly (P ≤ 0.05) increased the concentrations of those existing in raw meat. Direct-heat charcoal roast beef had 5 new PAHs and a total mean PAH content of 17.88 μg/kg, compared with a mean of 1.39 μg/kg for raw beef, with the potent dibenz(a,h)anthracene also being detected. Direct-heat charcoal roasted goat meat had three new PAHs and a total mean PAH content of 4.77 μg/kg, compared with a mean of 2.13 μg/kg in raw meat, with the potent benzo(a)pyrene concentration being 8.84% of the total mean PAH. Fried pork had 7 new PAHs and a total mean PAH content of 3.47 μg/kg, compared with a mean total of 0.17 μg/kg, detected in the raw meat. Roast beef had the highest individual PAH concentration (5.03 μg/kg) and highest total PAHs concentration (17.88 μg/kg), both being higher than acceptable EU limits. The PAHs from local raw and cooked meat were characterized and quantified for the first time in Kisumu City and the study therefore provided the needed baseline data on PAHs in raw and cooked meat.     

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.     

Influence of Dry Matter Content and Drying Conditions on Effective Diffusion Coefficient of Onion (Allium cepa,L.)

ABSTRACT

Demand for fresh and dehydrated onions has increased considerably over the last two decades. To meet this challenge new varieties possesing superior field characteristics have been developed whose dehydration characteristics differ markedly. In this work the influence of dry matter content in the raw onion and drying conditions on the effective diffusion coefficient is studied. In the falling rate period, the diffusion activation energy was found to be 33.9 kJ/mol, and the D_σ parameter (the effective diffusivity at high moisture contents) was found to be 5.0736×10^-5 m²/s. On the basis of measurements with seven different onion varieties (with raw dry matter content between 19.5 and 23.5 kg dry matter/kg fresh product) an exponential relationship was found between the effective diffusivity and dry matter content of the raw onion.     

Polycyclic Aromatic Hydrocarbons in Sediments of Marine Coastal Lagoons in Messina,Italy: Extraction and GC/MS Analysis,Distribution and Sources

The content of 21 polycyclic aromatic hydrocarbons (PAHs) were determined in 16 samples of sediments collected from Ganzirri and Faro marine coastal lagoons in Messina, Italy. Analysis was performed by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode. The total concentration of polycyclic aromatic hydrocarbons (ΣPAHs) ranged from 74 to 5755 μg/kg of dry matrix. The resulting distributions and molecular ratios of specific compounds are discussed in terms of sampling location and origin of organic matter. The results obtained show that levels of contamination are not homogeneous throughout the stations, while the relative distributions of PAHs are homogeneous in most of the sampling stations. The organic matter content and PAH concentration were found to be correlated (r = 0.90). It is also shown that the pyrolytic origin is the main source of these compounds in Ganzirri and Faro Lakes sediments.     

Effects of Temperature and Photocatalysts on Removal of Polycyclic Aromatic Hydrocarbons (PAHs) from Automotive Industry Sludge

This study was carried out to investigate the removability of polycyclic aromatic hydrocarbon (PAH) compounds existed in automotive industry treatment sludge. The impacts of temperature, UV, titanium dioxide (TiO₂), and diethyl amine (DEA) were studied in a controlled device which was specifically designed for this study. Sludge samples were collected from the treatment plant of an automotive manufacturing facility in Bursa, Turkey. The ∑₁₀ PAH concentration value in the sludge was 4480 ± 1450 ng/g dry matter (DM). ∑₁₀ PAH removal ratio was 30% at 37°C without UV irradiation. Moreover, the PAH content in the sludge was reduced up to 65% through applying UV irradiation. This figure reached 100% by using photo-catalysts (TiO₂ or DEA) at the rate of 20% of the DM of the sludge.