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^?).     

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 (PAH) IN DANISH SMOKED FISH AND MEAT PRODUCTS

Twenty seven PAH were detected in 45 selected smoked food samples produced in Denmark, including mackerel, herring, trout, small sausages, salami, and bacon. The sum of PAH in smoked meat products ranged from 24 μg/kg for salami to 64 μg/kg in bacon, while those in fish products ranged from 22 μg/kg in smoked mackerel prepared in an electric oven to 1387 μg/kg in herring smoked by direct smoking. The concentration of benzo[a]pyrene for all sample types were below the maximum level of 5 μg/kg for smoked fish and meat set by the European Commission. Results from this survey confirm that the actual level of individual PAH in fish products is dependent on variables such as the type of wood used in the smoking process. Furthermore, the use of the benzo[a]pyrene approach for estimation of the carcinogenicity of PAH in food is confirmed. The Danish intake of benzo[a]pyrene from these smoked products is 2 to 4 ng/person/day.     

Polycyclic Aromatic Hydrocarbons in Romanian Baby Foods and Fruits

Levels of polycyclic aromatic hydrocarbons (PAHs) in commercially available baby food and in different sorts of fruits were investigated. PAHs determination was performed by gas chromatography coupled with mass spectrometry (GC/MS). The sum of 15 PAHs varied in baby food from 2.52–6.7 μg/kg and in fruits from 0.40–21.52 μg/kg. Benzo[a]pyrene used as a marker for PAHs contamination was detected in lower levels in baby food than the maximum tolerable limit (1 μg/kg) stated in Commission Regulation no 1881/2006.     

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.     

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.     

Characterization of Gaseous and Particulate Polycyclic Aromatic Hydrocarbons in Ambient Air of Delhi,India

Three seasonal sampling campaigns were undertaken at an urban site of Delhi for collection of PAHs in particulate and gas phase. Sampling was done by using modified Respirable Dust (PM ≤10μm) sampler attached with polyurethane foam (PUF) plugs and compared with conventional Respirable Dust (PM ≤10 μm) sampler. Total 16 EPA PAH (gaseous + particulate) were determined by Gas Chromatograph-Mass Spectrophotometer (GC-MS). The 3-ring PAH constitutes approximately 90% of the gaseous PAHs with phenanthrene, fluoranthene, acenapthylene, and acenaphthene being the most abundant gaseous PAHs. PAHs with 4- to 6- rings accounted for 92%, 87% and 78% in samples collected during winter, summer and monsoon season respectively. Gaseous PAHs, particulate PAHs and total PAHs were higher during winter as compared to summer and monsoon seasons. The contribution of particulate PAHs were 1.4, 2.1, and 2.5 times higher in winter, summer and monsoon, respectively than of gaseous PAHs. Indeno[123-cd]pyrene, benzo[ghi]perylene, dibenzo[ah]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene and chrysene were found to be the most abundant PAH compounds in the particulate PAHs during all the seasons. The result from application of diagnostic ratio suggests that the higher particulate PAHs emissions were predominantly associated with vehicular emissions along with emissions from biomass burning during winter season.     

Determination of Polycyclic Aromatic Hydrocarbons in the fecal Materials of Mactra veneriformis and Excrement of Marphysa sanguinea

The concentration of polycyclic aromatic hydrocarbons (PAHs) was measured in the sediment, a bivalve (Mactra veneriformis), fecal materials (feces and pseudofeces) of M. veneriformis, and excrement (feces) of an annelid (Marphysa sanguinea), which were collected in the Yoro tidal flat in Chiba, Japan. The total PAH concentration was 350 μg/kg-dry in the fecal materials of M. veneriformis and 977 μg/kg-dry in the excrement of M. sanguinea; these values were about 8–23 times as large as that of the sediment. The concentration of the fecal materials stayed constant even after 24 h, whereas that of the excrement decreased to half in 2 h. The sediment and fecal materials of M. veneriformis showed a high level of PAHs with lower molecular weight such as phenanthrene, fluoranthene, and pyrene; on the other hand, the excrement of M. sanguinea showed a high level of PAHs with higher molecular weight such as chrysene, benzo[b]fluoranthene, benzo[a]pyrene, and perylene. The logarithm of the concentration factor, defined as the ratio of the concentration of individual PAHs in the fecal materials or excrement to that in the sediment, correlated with the logarithm of the n-octanol/water partition coefficient for the PAHs (R ² = 0.803). These findings indicate that the sources and characteristics of the fecal materials of M. veneriformis and the excrement of M. sanguinea are different.     

Polycyclic Aromatic Hydrocarbons (PAHs) Occurrence and Toxicity in Camellia sinensis and Herbal Tea

ABSTRACT

This study describes a survey of polycyclic aromatic hydrocarbon (PAH) concentrations in 23 green, herbal, and black tea brands widely consumed in Nigeria by determining the levels of benzo[a]pyrene, chrysene (PAH2), benzo[a]pyrene, chrysene, benz[a]anthracene, benzo[b]fluoranthene (PAH4), benzo[a]pyrene, benz[a]anthracene, benzo[k]fluoranthene, chrysene, benzo[b]fluoranthene, dibenz[ah]anthracene, benzo[ghi]per-ylene and indeno[1,2,3-cd]pyrene (PA-H8). Toxic equivalence factor and mutagenic equivalence factor were applied to evaluate the toxic equivalence and mutagenic equivalence quotients relative to benzo[a]pyrene. The concentrations of PAHs indicate that Regulation 835/2011/EC was not fulfilled by benzo[a]anthracene, B[a]A, benzo[a]pyrene, B[a]P, benzo[b]fluoranthene, B[b]F, and chrysene, CHR. The PAH4 levels ranged from 1.28 to 44.57, 4.34 to 11.20, and 0.76 to 34.82 µg/kg in green, black, and herbal tea products, respectively. On the other hand, the PAH8 concentration varied between 1.63 and 65.73, 5.02 and 68.83, and 12.43 and 24.92 µg/kg in green, herbal, and black tea samples. The PAH4 and PAH8 provide more reliable indicators for determination of PAH contamination and risk characterization in food than PAH2.     

Association of Polycyclic Aromatic Hydrocarbons (PAHs) with Different Sizes of Atmospheric Particulate in Hisar City and its Health Aspects

The concentration of polycyclic aromatic hydrocarbons (PAHs) associated with different particulate sizes of suspended particulate matter (SPM) was studied in Hisar city with the help of a MOUDI-NR 10-stage (18 μm to 0.056 μm) cascade impactor. The vehicular-cum-commercial, vehicular, commercial, and institutional/residential locations had the average concentration (ng/g) of 11.39, 10.39/10.22 (NH 10/Bus Terminus), 8.89, and 8.93, respectively. Vehicular emission was the chief source and diesel-vehicle dominated areas represented higher concentration of PAHs associated with coarse fraction. An increase in PAH associated with fine fraction was observed with an increase in vehicular density. Maximum average concentration (11.26 ng/g) was found to be associated in particle range of <0.56–0.32 μm. It was followed by particle range (μm) of <18–10, <1.8–1, <0.18–0.1, <1–0.56, <5.6–3.2, <0.32–0.18, <3.2–1.8 <0.1–0.056, and <10–5.6 with average values (ng/g) of 10.75, 10.35, 10.22, 10.16, 10.06, 9.50, 9.18, 9.18, and 9.00, respectively. Among the PAHs studied, maximum levels were observed for pyrene, followed by Benzo(b)fluoranthene, Benzo(e)pyrene, benzo(k)fluoranthene, fluoranthene, phenanthrene, benzo(ghi)perylene, anthracene, and naphthalene. With respect to the percent fraction of PAHs studied, the vehicular-cum-commercial area represented maximum fraction (22%) followed by vehicular area (21% each for NH-10 and Bus Terminus), institutional/residential area (18%), and commercial area (18%). The isomeric ratios revealed that most of the PAHs originate from combustion of diesel, gasoline, used engine oil, and coal/wood. The association of PAHs with fine fraction of health concern since it can penetrate and get accumulated in deep respiratory regions.     

Preparation of Test Material and Evaluation of a Proficiency Test for Official Food Control Laboratories on the Determination of Polycyclic Aromatic Hydrocarbons in Baby Food

A proficiency test on the determination of polycyclic aromatic hydrocarbons (PAHs) was organized by the German National Reference Laboratory for PAH in 2010. The test samples were produced by spiking cereal-based instant baby food with PAHs at concentration levels between 0.6 and 3.8 μg/kg; homogeneity and stability of the test material were verified before sample dispatch. Twenty-one official laboratories from Germany and Austria participated in the test and the evaluation of the test was done by applying methods of robust statistics. The individual performance was assessed with the help of z-scores. As to the quantitative results, the dispersion of data for the most important group of benzo(a)pyrene (BaP), benz(a)anthracene (BaA), benzo(b)fluoranthene (BbF), and chrysene (CHR) appeared to be acceptable, with a relative robust standard deviation ranging from 13.2% for BbF to 26.7% for BaA. In total, the performance of one laboratory had to be rated as unsatisfactory because of a result for BaP outside the limits of tolerance. The methods applied in the test may be considered to be comparable, as no significant effects in the distribution of data could be attributed to certain analytical procedures.     

Detection of polycyclic aromatic hydrocarbons in commonly consumed edible oils and their likely intake in the Indian population

Edible oils such as coconut, groundnut, hydrogenated vegetable, linseed, mustard, olive, palm, refined vegetable, rice bran, safflower, sesame, soybean, and sunflower were analyzed for the presence of light and heavy polycyclic aromatic hydrocarbon (PAH) residues using liquid-liquid extraction, cleanup on a silica gel column, and resolution and determination by HPLC using a fluorescence detector. Ten PAH viz. acenaphthene, anthracene, benzo(a)pyrene, benzo(e)pyrene, benz(ghi)perylene, chrysene, coronene, cyclopenta(def)phenanthrene, phenanthrene, and pyrene were monitored. Analysis of 296 oil samples showed that 88.5% (262) samples were contaminated with different PAH. Of 262 contaminated edible oil samples, 66.4% of the samples showed PAH content of more than the 25 μg/kg recommended by the German Society for Fat Science. The total PAH content was highest in virgin olive oil (624 μg/kg) and lowest in refined vegetable oils (40.2 μg/kg). The maximum content (265 μg/kg) of heavy PAH was found in olive oil and the minimum (4.6 μg/kg) in rice bran oil. Phenanthrene was present in 58.3% of the oil samples analyzed, followed by anthracene (53%). Among the heavy PAH, benzo(e)pyrene was observed in 31.2% of the samples followed by benzo(a)pyrene (25.5%). The intake of PAH was highest through olive oil (20.8 μg/day) followed by soybean oil (5.0 μg/day) and lowest through refined vegetable oil (1.3 μg/day). Based on these monitoring studies, international and national guidelines for permissible levels of PAH can be prepared so as to restrict the intake of these toxic contaminants.     

Levels of 15 + 1 EU Priority Polycyclic Aromatic Hydrocarbons in Different Edible Oils Available in the Syrian Market

ABSTRACT

The levels of 15 + 1 EU priority polycyclic aromatic hydrocarbons (15 + 1 EU PAHs) have been determined in different edible oils (extra virgin olive oil, virgin olive oil, sunflower oil, corn oil, and soybean oil) available in the Syrian market. The samples have been prepared by donor–acceptor complex chromatography and subsequently characterized by high-pressure liquid chromatography coupled with fluorescence and ultraviolet detection for quantification purposes. Variable levels of contamination have been found within different kinds of edible oil samples, and only chrysene has been detected in all the studied samples. Moreover, the mean total sum of 15 + 1 EU PAHs has shown variation from 29.8 µg/kg (corn oil) to 63.7 µg/kg (virgin olive oil). A total of 11 samples out of 38 samples (28.9%) have not fulfilled the European Union (EU) food law requirements. Nine samples have exceeded the EU legislation limit of benzo[a]pyrene (BaP) (2 µg/kg) and only two samples have exceeded the EU legislation limit of PAH4 (10 µg/kg) and had acceptable level of BaP. Finally, the mean and maximum dietary exposures of PAHs through consumption of edible oils have been estimated.     

Bioaccumulation of PAHs and Their Hydroxylated Metabolites in Common Carp (Cyprinus Carpio Linnaeus 1758) in Controlled Environment

Abstract

This study aimed to determine the incorporation of PAHs into muscle of Cyprinus carpio. Three model compounds (phenanthrene, pyrene and benzo[a]pyrene) were orally administered during 56 days, in a series of three increasing doses (0, 100, 500 μg of each PAHs per kg of fish). PAHs and their hydroxylated metabolites were analyzed by a HPLC-Fluorimetry method. Results of this study showed a significant increase of phenanthrene and pyrene in muscle. Benzo[a]pyrene incorporation to muscle was not effective. Concerning hydroxylated metabolites, they were not detected in muscle of carp. Steady states for phenanthrene and pyrene were obtained after 28 days of exposure. Low incorporation to muscle was observed at equilibrium for phenanthrene (6% and 3%) and pyrene (3% and 1%), depending of the dose tested.     

Monitoring of Polycyclic Aromatic Hydrocarbons in Water during Preparation Processes

This article presents results on investigation of quantitative changes of polycyclic aromatic hydrocarbons (PAHs) during water treatment processes. PAHs constitute one of several classes of organic pollutants consisting of three or more fused benzene rings. Many of them are quite persistent and some are known to be carcinogens. That is why presentation of quantitative PAHs changes in water during preparation processes is very important. In Polish legislation and European Union law there are recommendations for PAHs concentration in drinking water. The limit value of the sum of 4 PAHs (benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[g,h,i]perylene, indeno[1,2,3-cd]pyrene) is 100 ng/L. Limit concentration of benzo[a]pyrene defined in regulations (Polish and UE) is 10 ng/L. The purpose of the present study was to determine changes of concentrations of PAHs in various stages of water treatment process and comparison the values of this index with the limits specified in valid Minister of Health Regulation and Council Directive 98/83/EC. A total concentration of 16 PAHs in the investigated water treatment processes was in the range of 39–204 ng/L. The maximum level was recorded for water after intermediate ozonation. In different water treatment processes were observed fluctuations in PAHs concentrations. Decreased values were recorded among others after pre-ozonation and coagulation and after sedimentation process. Increase of PAHs level occurred after filtration through sand filters. Concentrations of 4 PAHs in drinking water is much below the limit value defined in Polish and UE legislation. Concentration of 16 PAHs in water after final chlorine-disinfection also meets the requirements of the regulation for 4 PAHs.     

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.     

Total Long-Chain n-3 Fatty Acid Intake and Food Sources in the United States Compared to Recommended Intakes: NHANES 2003–2008

The American Heart Association recommends consuming fish (particularly oily fish) at least two times per week, which would provide ≈ 0.5 g/day of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) for cardiovascular disease risk reduction. Previous analyses indicate that this recommendation is not being met; however, few studies have assessed different ethnicities, subpopulations requiring additional n-3 fatty acid intake (i.e., children and pregnant and/or lactating women), or deciles of intake. Data from the National Health and Nutrition Examination Survey 2003–2008 was used to assess n-3 fatty acid intake from foods and supplements in the US population, according to age, sex, and ethnicity. A unique “EPA equivalents” factor, which accounts for potential conversion of shorter-chain n-3 fatty acids, was used to calculate total long-chain n-3 fatty acid intake. Data are reported for 24,621 individuals. More than 90% consumed less than the recommended 0.5 g/day from food sources (median = 0.11 g/day; mean = 0.17 g/day). Among the top 15% of n-3 fatty acid consumers, fish was the largest dietary contributor (71.2%). Intake was highest in men aged 20 years or more, and lowest in children and women who are or may become pregnant and/or are lactating. Among ethnicities, intake was lowest in Mexican-Americans. Only 6.2% of the total population reported n-3 fatty acid supplement use, and this did not alter median daily intake. Additional strategies are needed to increase awareness of health benefits (particularly among Mexican-Americans and women of childbearing age) and promote consumption of oily fish or alternative dietary sources to meet current recommendations.     

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.     

Major gaseous and PAH emissions from a fluidized-bed combustor firing rice husk with high combustion efficiency

This experimental work investigated major gaseous (CO and NO_x) and PAH emissions from a 400 kW_th fluidized-bed combustor with a cone-shaped bed (referred to as ‘conical FBC’) firing rice husk with high, over 99%, combustion efficiency. Experimental tests were carried out at the fuel feed rate of 80 kg/h for different values of excess air (EA). As revealed by the experimental results, EA had substantial effects on the axial CO and NO_x concentration profiles and corresponding emissions from the combustor. The concentration (mg/kg-ash) and specific emission (μg/kW h) of twelve polycyclic aromatic hydrocarbons (PAHs), acenaphthylene, fluorene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene and indeno[1,2,3-cd]pyrene, were quantified in this work for different size fractions of ash emitted from the conical FBC firing rice husk at EA = 20.9%. The total PAHs emission was found to be predominant for the coarsest ash particles, due to the effects of a highly developed internal surface in a particle volume. The highest emission was shown by acenaphthylene, 4.1 μg/kW h, when the total yield of PAHs via fly ash was about 10 μg/kW h.     

Contamination of Soil by Polycyclic Aromatic Hydrocarbons in Some Urban Areas

The contamination by 16 polycyclic aromatic hydrocarbons (PAHs) in surface soils, sampled at a 0-5 cm depth in the urban areas of Tallinn, Helsinki, Vilnius, Chicago, London is reported. All samples were analyzed using the same protocol. The median concentrations ( w g/kg) were found to be 117, 539, 127, 3,263, 1,728 for pyrene; 62, 236, 43, 1,634, 1,652 for benzo[ a ]pyrene; 86, 304, 92, 2,295, 2,068 for benzo[ a ]pyrene toxic equivalents, calculated using the benzo[ a ]pyrene toxic equivalency factors; 467, 1,471, 392, 8,981, 6,837 for a total of seven probable human carcinogenic PAHs: benzo[ a ]anthracene, chrysene, benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene, dibenz[ ah ]anthracene, indeno[1,2,3- cd ]pyrene; 911, 2,941, 672, 16,183, 13,718 for the total of 16 PAHs, recommended by the U.S. Environmental Protection Agency: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[ a ]anthracene, chrysene, benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene, dibenz[ ah ]anthracene, benzo[ ghi ]perylene, indeno[1,2,3- cd ]pyrene in Tallinn ( n = 3), Helsinki ( n = 3), Vilnius ( n = 15), Chicago ( n = 4), London ( n = 3), respectively. The size of the population is a statistically significant factor in urban soil contamination by high-molecular-mass PAHs.