Tissue distribution and depuration of 4-tert-octylphenol residues in the cyprinid fish,Scardinius erythrophthalmus

Alkylphenols are present in the aquatic environment through the degradation of alkylphenolpolyethoxylate surfactants in sewage treatment works. Branched chain 4-alkylphenols have been shown to retard testicular growth and stimulate vitellogenin synthesis in freshwater fish. We conducted in vivo studies in order to determine the fate and persistence of radiolabeled 4-tert-octylphenol (tOP) in the cyprinid fish, rudd (Scardinius erythrophthalmus). Sexually mature rudd were exposed to a concentration of 4.7 microg/L of [14C] tOP in a flow through system for 10 days. Radioactive residues were extracted from soft tissues and analyzed by radio-high-performance liquid chromatography. tOP accumulated as the major residue in muscle, ovary, and testis with bioconcentration factors of 24, 85, and 169, respectively. tOP residues in blood, gill, kidney, liver, and bile were extensively metabolized. Analysis of tOP residues in bile revealed 10 major metabolites, which were identified by GC-MS as products of aromatic and aliphatic hydroxylation, glucuronidation, and glucosidation. Depuration studies with exposed fish placed in clean water for up to 10 days resulted in a rapid loss of soluble residues from the tissues with half-lives of between 0.7 and 1.0 days (muscle, testis, ovary, gill, blood, kidney), 1.7 days (liver), and 5.9 days (bile). A further portion of radioactive residues was extracted from blood, gill, kidney, and liver after alkaline digestion, suggesting the formation of covalently bound protein adducts in these tissues. This study suggests that although para-alkyphenolic xenoestrogens can accumulate in muscle and the gonads of adult fish, residues are rapidly depurated from these tissues. Furthermore, analysis of the parent alkylphenol in bile, after hydrolysis of the conjugates, is likely to significantly underestimate the total concentration of alkylphenol residues and may not serve as an appropriate biomarker for quantifying the exposure of wild fish to alkylphenols.     

Tissue distribution and residue depletion of metronidazole in rainbow trout (Oncorhynchus mykiss)

Tissue distribution and residue depletion of metronidazole (MNZ) was studied in rainbow trout (Oncorhynchus mykiss) following oral administration of MNZ in feed at the average dose of 25 mg kg^?1 body weight day^?1 for 7 days at 11 ± 2°C. The MNZ concentration in feed was 0.25% while daily feed intake was 1% of body weight. The concentrations of MNZ and its main metabolite, hydroxymetronidazole (MNZOH), in fish tissues were determined by LC-MS/MS. The drug was well distributed in tissues with maximum concentrations on day 1 post-administration. At this time, the mean MNZ concentrations in muscle, skin, kidney, liver and gill were 14 999, 20 269, 15 070, 10 102 and 16 467 µg kg^?1 respectively. MNZ was converted into MNZOH with the ratio of MNZOH:MNZ up to 7% in all fish tissues throughout the withdrawal period. This shows that MNZ itself is the main residue in rainbow trout. MNZ was detected at the level close to the decision limit (0.20 µg kg^?1) in muscle, skin and muscle with adhering skin up to 42 days, while in kidney, liver and gill it was up to 28 days post-administration. MNZOH was eliminated more rapidly from fish tissues and it was present in muscle alone up to 21 days. The elimination half-lives of MNZ and MNZOH in rainbow trout tissues were 1.83–2.53 and 1.24–2.12 days, respectively. When muscle without skin was analysed, higher MNZ and MNZOH concentrations were detected, and for a longer period of time, than in muscle with adhering skin. Thus muscle alone could be more appropriate for the effective residue control of MNZ in rainbow trout. For the same reason, it is also essential to ensure direct cooling immediately after sampling, since MNZ and its metabolite degrade in fish muscle and skin stored in non-freezing conditions.     

Rapid determination of (carbon-14) glucose specific radioactivity for in vivo glucose kinetics.

Specific radioactivity of blood glucose was determined by use of a Dowex-1 anion-exchange column after (carbon-14) glucose was infused for in vivo kinetics. The first 20-ml eluate of protein-free blood filtrate from the column was discarded; then 10 ml was collected, lyophilized, and counted in a liquid-scintillation counter. Glucose concentration was determined and specific radioactivity calculated. Kinetic results were comparable to those obtained with the more laborious glucose-pentaacetate procedure.     

Tissue distribution and elimination of deoxynivalenol and ochratoxin A in dietary-exposed Atlantic salmon (Salmo salar)

ABSTRACT

Post-smolt Atlantic salmon (Salmo salar) were fed standard feed with added 2 or 6 mg kg^–1 pure deoxynivalenol (DON), 0.8 or 2.4 mg kg^–1 pure ochratoxin A (OTA), or no added toxins for up to 8 weeks. The experiments were performed in duplicate tanks with 25 fish each per diet group, and the feed was given for three 2-h periods per day. After 3, 6 and 8 weeks, 10 fish from each diet group were sampled. In the following hours after the last feeding at 8 weeks, toxin elimination was studied by sampling three fish per diet group at five time points. Analysis of DON and OTA in fish tissues and plasma was conducted by liquid chromatography-mass spectrometry and high-pressure liquid chromatography with fluorescence detection, respectively. DON was distributed to the liver, kidney, plasma, muscle, skin and brain, and the concentrations in liver and muscle increased significantly from 3 to 8 weeks of exposure to the high-DON diet. After the last feeding at 8 weeks, DON concentration in liver reached a maximum at 1 h and decreased thereafter with a half-life (t_1/2) of 6.2 h. DON concentration in muscle reached a maximum at 6 h and was then eliminated with a t_1/2 = 16.5 h. OTA was mainly found in liver and kidney, and the concentration in liver decreased significantly from 3 to 8 weeks in the high-OTA group. OTA was eliminated faster than DON from various tissues. By using Norwegian food consumption data and kinetic findings in this study, we predicted the human exposure to DON and OTA from fish products through carryover from the feed. Following a comparison with tolerable daily intakes, we found the risk to human health from the consumption of salmon-fed diets containing maximum recommended levels of these toxins to be negligible.     

皮革中多环芳烃(PAHs)测定方法

介绍了皮革中多环芳烃的测定方法,样品用正己烷经加速溶剂萃取、凝胶渗透色谱净化、自动定量浓缩后,用气相色谱质谱联用仪测定。方法检测低限为0.20μg/mL,实验室内相对标准偏差小于5%,回收率除萘以外均大于80%。     

Distribution of polycyclic aromatic hydrocarbons (PAHs) in rivers and estuaries in Malaysia: a widespread input of petrogenic PAHs

This is the first publication on the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in riverine and coastal sediments in South East Asia where the rapid transfer of land-based pollutants into aquatic environments by heavy rainfall and runoff waters is of great concern. Twenty-nine Malaysian riverine and coastal sediments were analyzed for PAHs (3-7 rings) by gas chromatography mass spectrometry. Total PAHs concentrations in the sediment ranged from 4 to 924 ng/g. Alkylated homologues were abundant for all sediment samples. The ratio of the sum of methylphenanthrenes to phenanthrene (MP/P), an index of petrogenic PAHs contribution, was more than unity for 26 sediment samples and more than 3 for seven samples for urban rivers covering a broad range of locations. The MP/P ratio showed a strong correlation with the total PAHs concentrations, with an r2 value of 0.74. This ratio and all other compositional features indicated that Malaysian urban sediments are heavily impacted by petrogenic PAHs. This finding is in contrast to other studies reported in many industrialized countries where PAHs are mostly of pyrogenic origin. The MP/P ratio was also significantly correlated with higher molecular weight PAHs such as benzo[a]pyrene, suggesting unique PAHs source in Malaysia which contains both petrogenic PAHs and pyrogenic PAHs. PAHs and hopanes fingerprints indicated that used crankcase oil is one of the major contributors of the sedimentary PAHs. Two major routes of inputs to aquatic environments have been identified: (1) spillage and dumping of waste crankcase oil and (2) leakage of crankcase oils from vehicles onto road surfaces, with the subsequent washout by street runoff. N-Cyclohexyl-2-benzothiazolamine (NCBA), a molecular marker of street dust, was detected in the polluted sediments. NCBA and other biomarker profiles confirmed our hypothesis of the input from street dust contained the leaked crankcase oil. The fingerprints excluded crude oil, fresh lubricating oil, asphalt, and tire-particles as major contributors.     

Tissue distribution of perfluorinated surfactants in common guillemot (Uria aalge) from the Baltic Sea

Perfluorinated alkyl surfactants (PFAS) were investigated in tissues and organs of the common guillemot (Uria aalge) from the Baltic Sea. Concentrations of 11 perfluorinated carboxylates, four perfluorinated sulfonates, and perfluorooctane sulfonamide were determined in egg, liver, kidney, and muscle of adult guillemot, as well as in liver from chicks, all sampled in 1989. Additionally, whole herring homogenates from 2005 were analyzed, herring comprising a large part of guillemot's diet. Quantifiable concentrations of PFAS were found in all samples. Perfluorooctane sulfonate (PFOS) was predominant, followed by perfluorotridecanoate (PFTriDA) and perfluoroundecanoate (PFUnDA). The median concentration of PFOS was highest in eggs (325 ng/g wet weight (w wt)) followed by chick liver (309 ng/g w wt), kidney (127 ng/g w wt), adult liver (121 ng/g w wt), and muscle (14 ng/g w wt). Comparatively low levels of PFOS were found in herring, leaving a blurred picture of uptake routes. PFAS concentrations in livers of male and female guillemots did not differ significantly. Some PFAS showed higher concentrations in eggs than in female livers. The ratio of levels in egg/female liver, indicating mother-to-egg transfer capacity, increased with increasing PFAS chain length. PFOS showed a higher tendency for transfer than carboxylates of carbon chain lengths C9-C13.     

Reductions of Vibrio parahaemolyticus in Pacific oysters (Crassostrea gigas) by depuration at various temperatures

Consumption of raw oysters has been linked to several outbreaks of Vibrio parahaemolyticus infection in the United States. This study investigated effects of ice storage and UV-sterilized seawater depuration at various temperatures on reducing V. parahaemolyticus in oysters. Raw Pacific oysters (Crassostrea gigas) were inoculated with a mixed culture of five clinical strains of V. parahaemolyticus (10290, 10292, 10293, BE 98-2029 and 027-1c1) at levels of 10⁴⁻⁶ MPN/g. Inoculated oysters were either stored in ice or depurated in recirculating artificial seawater at 2, 3, 7, 10, 12.5, and 15 °C for 4–6 days. Holding oysters in ice or depuration of oysters in recirculating seawater at 2 or 3 °C for 4 days did not result in significant reductions (P > 0.05) of V. parahaemolyticus in the oysters. However, depuration at temperatures between 7 and 15 °C reduced V. parahaemolyticus populations in oysters by >3.0 log MPN/g after 5 days with no loss of oysters. Depuration at refrigerated temperatures (7–15 °C) can be applied as a post-harvest treatment for reducing V. parahaemolyticus in Pacific oysters.     

Tissue distribution of perfluorinated chemicals in harbor seals (Phoca vitulina) from the Dutch Wadden Sea

Perfluorinated acids (PFAs) are today widely distributed in the environment, even in remote arctic areas. Recently, perfluorooctane sulfonate (PFOS) has been identified in marine mammals all over the world, but information on the compound-specific tissue distribution remains scarce. Furthermore, although longer perfluorinated carboxylic acids (PFCAs) are used in industry and were shown to cause severe toxic effects, still little is known on potential sources or their widespread distribution. In this study, we report for the first time on levels of longer chain PFCAs, together with some short chain PFAs, perfluorobutane sulfonate (PFBS) and perfluorobutanoate (PFBA), in liver, kidney, blubber, muscle, and spleen tissues of harbor seals (Phoca vitulina) from the Dutch Wadden Sea. PFOS was the predominant compound in all seal samples measured (ranging from 89 to 2724 ng/g wet weight); however, large variations between tissues were monitored. Although these are preliminary results, it is, to our knowledge, the first time that PFBS could be found at detectable concentrations (2.3 +/- 0.7 ng/g w wt) in environmental samples. PFBS was only detected in spleen tissue. PFCA levels were much lower than PFOS concentrations. The dominant PFCA in all tissues was PFNA (perfluorononanoic acid), and concentrations generally decreased in tissues for all other PFCA homologues with increasing chain length. No clear relationship between PFOS levels in liver and kidney was observed. Furthermore, hepatic PFDA (perfluorodecanoic acid) levels increased with increasing body length, but in kidney tissue, PFDA levels showed an inverse relationship with increasing body length. These data suggest large differences in tissue distribution and accumulation patterns of perfluorinated compounds in marine organisms.     

Polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air of Hangzhou, China

Twelve polycyclic aromatic hydrocarbons were simultaneously measured in indoor and outdoor air of eight homes in Hangzhou, China in both summer and autumn in 1999. It was observed that the sum of PAHs concentrations in indoor air were ranged from 1.418 to 20.466 micrograms/m3 in summer and from 3.897 to 29.852 micrograms/m3 in autumn; the corresponding concentrations in outdoor air were between 1.380 and 20.468 micrograms/m3 in the summer and between 2.721 and 30.678 micrograms/m3 in autumn. The PAHs concentrations in indoor air generally exceeded that in the corresponding outdoor air. It was indicated that the two-, three-, and four-ring PAHs were predominantly in vapor phase, while the five-ring PAHs were primarily associated with the particulate phase. The fraction of PAHs in vapor phase will increase with the increase of temperature. Among the 12 PAHs, naphthalene was the most abundant PAHs found in indoor and outdoor air. Both in summer and autumn, it contributed more than 60% to the sum of PAHs. Because of the different functions and ventilation conditions, the concentrations of PAHs in the rooms were bedroom > kitchen > living room > balcony. By the contrast of BaP concentrations in smoker and nonsmoker's homes, we know that smoking in indoors could contribute 67% of BaP to the homes.     

恒能量同步荧光法测定食品中的多环芳烃

建立了食品中多环芳烃的恒能量同步荧光谱测定方法。样品经环己烷超声波提取,硅胶过柱。优化了六种多环芳烃(PAHs)化合物的测定条件。六种样品(PAHs)回收率范围为77.48%～101.76%;相对标准偏差为0.97%～2.19%。结果表明,此方法具有灵敏度高,准确度好,能同时分离测定六种多环芳烃化合物的优点,适合于食品中多环芳烃化合物的分析测定。     

Baking kinetics of muffins in convection and steam assisted hybrid ovens (baking kinetics of muffin…)

Effects of oven type and baking temperature on acrylamide concentration, surface browning, temperature profiles and drying rates of muffins were investigated. Muffins were baked in convection and steam assisted hybrid ovens at 145, 160 and 175 °C for different baking times. For all oven types, the acrylamide concentration of muffins increased with increasing baking time and temperature (p < 0.05). The formation was considered as the first order reaction kinetics except for the lowest baking temperature at natural convection and steam assisted hybrid ovens. The reaction rate constant, k was found to be in the range of 0.027–0.078 (min⁻¹). For the forced convection oven, the effect of baking temperature on acrylamide concentration followed the Arrhenius type of equation; with activation energy of 36.35 kJ/mol. The minimum drying rate was observed by the steam assisted hybrid oven, at all conditions. Steam assisted baking resulted in lower acrylamide concentration at all baking temperatures, while providing the average moisture content not significantly different.     

Review of the quantification techniques for polycyclic aromatic hydrocarbons (PAHs) in food products

There is a growing need for accurate detection of trace-level PAHs in food products due to the numerous detrimental effects caused by their contamination (e.g., toxicity, carcinogenicity, and teratogenicity). This review aims to discuss the up-to-date knowledge on the measurement techniques available for PAHs contained in food or its related products. This article aims to provide a comprehensive outline on the measurement techniques of PAHs in food to help reduce their deleterious impacts on human health based on the accurate quantification. The main part of this review is dedicated to the opportunities and practical options for the treatment of various food samples and for accurate quantification of PAHs contained in those samples. Basic information regarding all available analytical measurement techniques for PAHs in food samples is also evaluated with respect to their performance in terms of quality assurance.     

Polycyclic aromatic hydrocarbons (PAHs) in different types of smoked meat products from Serbia

The contents of the16 EU priority PAHs in six different meat products from Serbia (beef ham, pork ham, bacon without skin, bacon with skin, cajna sausage and sremska sausage) were examined during the process of smoking. All these meat products from meat industry Zlatiborac, Mačkat, Serbia presented in this study, have not previously been analysed concerning to their contents of PAH compounds. Determination and quantification of PAHs in meat products were performed by a Fast GC/HRMS method. The maximum level for benzo[a]pyrene (BaP) of 5 μg/kg in smoked meat products was not exceeded in any samples. BaP comprises in general 4.6% of the total sum of the 16 EU priority PAHs and 15.2% of the total sum of the 12 IARC PAH compounds. The suitability of BaP as a marker both for 16 EU priority PAHs and 12 IARC probably and possibly carcinogenic PAHs was checked by applying correlation analysis.     

Polycyclic aromatic hydrocarbons (PAHs) in traditional and industrial smoked beef and pork ham from Serbia

Smoked beef and pork ham samples were analysed during process of smoking (after packing and storing) for the presence of the 16 EU priority PAHs via Fast GC/HRMS method. This study showed that there are differences in PAH contents between final smoked beef ham samples from traditional smokehouse (TS) (3.9 μg kg⁻¹) and industrial smokehouse (IS), (1.9 μg kg⁻¹). Also there is a difference in PAH contents in final smoked pork ham samples (4.9 μg kg⁻¹, TS; 4.2 μg kg⁻¹, IS). In beef and pork ham samples from the same smokehouse different PAH contents were observed during smoking. The highest content of examined PAHs in all beef and pork ham samples during smoking showed benzo[c]fluorene (BcL) (beef ham: from 0.3 μg kg⁻¹ to 1.5 μg kg⁻¹; pork ham: from 0.2 μg kg⁻¹ to 2.1 μg kg⁻¹).The maximum level for benzo[a]pyrene (BaP) of 5 μg kg⁻¹ in smoked meat products was not exceeded in any samples. Correlation statistic analysis (P < 0.05) of obtained contents from samples both from TS and IS showed that BaP is a good marker both for 16 EU priority PAHs and 12 IARC probably and possibly carcinogenic PAHs (IS: R _BaP/Σ16PAHs = 0.95, R _BaP/Σ12PAHs = 0.96; TS: R _BaP/Σ16PAHs = 0.71, R _BaP/Σ12PAHs = 0.88).     

Simultaneous formation of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HCAs) in gas-grilled beef satay at different temperatures

This study investigated the simultaneous formation of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatic amines (HCAs) in gas-grilled beef satay at different temperatures (150, 200, 250, 300, and 350°C). Solid-phase extraction (SPE) was used for sample clean-up. Fifteen PAHs were determined using high performance liquid chromatography with fluorescence detection (HPLC-FLD) and nine HCAs were quantified using liquid chromatography tandem-mass spectrometry (LC-MS/MS) with a gradient programme. The lowest significantly concentrations of PAHs and HCAs were generated at 150°C; the formation of PAHs and HCAs simultaneously increased with temperatures. Benzo[a]pyrene was detected in all samples and increased markedly at 300 and 350°C. The sums of 4 PAHs (PAH4) in marinated beef satay at 300 and 350°C exceeded the maximum level in Commission Regulation (EU) 2015/1125. Significant reductions of polar and non-polar HCAs (except PhIP) were found in marinated beef satay across all temperatures. Overall, PAHs and HCAs showed opposite trends of formation in beef satay with marination.     

Optimisation and validation of an HPLC method for determination of polycyclic aromatic hydrocarbons (PAHs) in mussels

A method for determination of 11 polycyclic aromatic hydrocarbons (PAHs) in mussels (Mytilus galloprovincialis), using HPLC coupled to a fluorescence detector, has been optimised and validated, according to European Community rules. Sample preparation involves alkaline digestion of mussel tissue, liquid–liquid extraction of organic compounds and solid phase clean-up. Accuracy and precision of the method were determined by a validation study, carried out to demonstrate that the method is useful for both screening purposes and confirmation. Commission Regulation (EC) No. 2007/333/EC stated the performance criteria for the analysis of the only benzo[a]pyrene (BaP) in food products of animal origin, since BaP is the most studied PAH. We extended the BaP analysis performance criteria to other 10 toxic PAHs (listed in Commission Recommendation (EC) No. 2005/108/EC) and the validation study was performed also in agreement with Commission Decision (EC) No. 2002/657/EC. The method was applied to investigate 27 mussel samples from actively producing shellfish plants located in Campania (Italy) and variable levels of PAHs were detected ranging from <0.2 to 16 μg/kg wet weight.     

Uptake of Escherichia coli, Vibrio cholerae non-O1 and Enterococcus durans by, and depuration of mussels (Mytilus galloprovincialis)

The uptakes of Escherichia coli, Vibrio cholerae non-O1 and Enterococcus durans by mussels (Mytilus galloprovincialis) and the times for depuration were investigated in order to determine the most useful indicator of vibrio contamination. The mussels were maintained in tanks of static seawater contaminated with bacteria at 5 log10 CFU/ml for bioaccumulation. Depuration was carried out by circulating fresh seawater through the tanks. Each organism was presented alone and with others to mussels, at temperatures of 14 and 21 degrees C. In water contaminated with either single or mixed organisms, the bacteria accumulated rapidly in the mussels reaching high concentrations after 1 h. With both single and mixed organisms, the maximum numbers of E. coli in mussels were 6.6 log10 CFU/g at 14 degrees C and 5.4 log10 CFU/g at 21 degrees C. Both V. cholerae non-O1 and E. durans alone or with other organisms reached a number ranging from 6.5 to 7 log10 CFU/g at both temperatures. During depuration the numbers of all the organisms slowly decreased, with E. coli alone, numbers ranged from 2.8 to 2 log10 CFU/g after 72 h at both 14 and 21 degrees C, and the organisms were undetectable after 144 h. With mixed organisms at 14 degrees C E. coli became undetectable after 168 h but at 21 degrees C no E. coli were recovered after 72 h. At 14 degrees C V. cholerae non-O1 alone also was undetectable after 168 h, but at 21 degrees C and with mixed organisms at both temperatures. V. cholerae was recovered after 168 h at numbers about 1 log10 CFU/g. After 168 h numbers of E. durans alone ranged from 2.6 log10 CFU/g at 14 degrees C to 1.5 log10 CFU/g at 21 degrees C, and with mixed organisms the numbers ranged from 2.3 to 2.0 log10 CFU/g at both temperatures. Of the three bacteria of faecal origin, E. durans is quickly acquired by mussels and released more slowly than the others, while E. coli quickly becomes undetectable. The results suggest that, for this kind of seafood, enterococci may be a more appropriate indicator than E. coli of risks to consumers from vibrios.     

Benzo[a]pyrene and total polycyclic aromatic hydrocarbons (PAHs) levels in vegetable oils and fats do not reflect the occurrence of the eight genotoxic PAHs

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were determined in 115 samples of olive oil (extra virgin olive oil, virgin olive oil, olive oil, pomace olive oil and blended olive oil), cooking oil (corn oil, sunflower oil, sesame oil, palm olein oil, soya oil, canola oil, mustard oil, peanut oil and mixed vegetable oil) and fat (butter and table margarine) collected from retail stores in Kuwait. Carcinogenic benzo[a]pyrene (BaP) was detected in 43% of the samples analyzed. Benz[a]anthracene and chrysene were detected in 37 and 45% of the samples, respectively, that did not contain BaP. Of the individual non-carcinogenic PAHs, naphthalene showed the highest mean concentration (14 µg kg^?1), while for the carcinogenic PAHs, BaP (0.92 µg kg^?1) and chrysene (0.87 µg kg^?1) showed the highest mean values. Approximately 20% of the samples within the olive oil and cooking oil sub-categories exceeded the EU maximum tolerable limit for BaP, with the highest level of 6.77 and 11.1 µg kg^?1, respectively. For the fat sub-category, 9% of the samples exceeded the tolerance limit, with the highest level of 3.67 µg kg^?1. The Kuwaiti general population's dietary exposure to the genotoxic PAHs (PAH8: benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene and benzo[ghi]perylene) was estimated to be 196 ng day^?1 (3.3 ng kg^?1 bw day^?1, assuming an average adult body weight of 60 kg). Results indicated that PAH8 and BaP_eq (total sum benzo[a]pyrene equivalents) are more reliable measures of the concentrations of other carcinogenic PAHs in oil and fat samples, while BaP and PAHs alone are not good indicators of the occurrence or degree of contamination by carcinogenic PAHs in these food products.