Concentration, dietary exposure and health risk estimation of polycyclic aromatic hydrocarbons (PAHs) in youtiao, a Chinese traditional fried food

Food Control 59 (2016) 328e336

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Concentration, dietary exposure and health risk estimation of polycyclic aromatic hydrocarbons (PAHs) in youtiao, a Chinese traditional fried food Ge Li a, b, Shimin Wu a, b, c, *, Lin Wang a, Casimir C. Akoh d a

Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China Bor S. Luh Food Safety Research Center, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China c Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Dongchuan Road 800, Shanghai 200240, China d Department of Food Science and Technology, University of Georgia, Food Science Building, Athens, GA 30602-2610, USA b

a r t i c l e i n f o

a b s t r a c t

Article history: Received 21 November 2014 Received in revised form 27 May 2015 Accepted 1 June 2015 Available online 4 June 2015

Youtiao, or oil stick, is a typical, traditional and widely-consumed fried food in China. The concentration of polycyclic aromatic hydrocarbons (PAHs) in youtiao from different origins was determined. The dietary exposure and cancer risk associated with benzo[a]pyrene equivalents from youtiao consumption were estimated using Monte Carlo simulation. Analysis of 16 PAHs in youtiao was completed by gas chromatography-mass spectrometry (GC-MS). Concentrations of the sum of 16 PAHs were between 9.90 and 89.97 mg/kg. The sum concentrations of PAH4, including benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF) and benzo[a]pyrene (BaP), ranged from 1.41 to 26.56 mg/kg. The median dietary exposure of BaPeq concentrations from youtiao for children, adolescents, adults and seniors in China, were 0.0147, 0.0101, 0.0561 and 0.0106 ng/(kg$day), respectively. Health risk estimates expressed as the 95th percentile incremental lifetime cancer risks (ILCRs) with respect to PAHs indicated a slight potential carcinogenic risk for children in northern China and adults in both the north and south. © 2015 Elsevier Ltd. All rights reserved.

Keywords: Polycyclic aromatic hydrocarbons Dietary exposure Incremental lifetime cancer risk Youtiao Fried food

1. Introduction Polycyclic aromatic hydrocarbons (PAHs) are a large group of well-known toxic environmental and food processing contaminants containing two or more fused aromatic rings. Based on the number of condensed aromatic rings, they can be divided into light (2e4 rings) and heavy (5 or more rings) PAHs. It has been known for a long time that a number of PAHs have carcinogenic, mutagenic and teratogenic properties. The heavy PAHs, such as benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenzo[a,h]anthracene, and benzo [g,h,i]perylene, are more stable and toxic than the light ones. Other PAHs which are not defined as carcinogens may act as synergists ~ os, Frenich, & Vidal, 2010). The metabolism of PAHs has (Plaza-Bolan also been studied in a number of laboratory animals, human cells and tissues, and shown to have substantial contribution to several

* Corresponding author. Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, China. E-mail address: [email protected] (S. Wu). http://dx.doi.org/10.1016/j.foodcont.2015.06.003 0956-7135/© 2015 Elsevier Ltd. All rights reserved.

types of human cancers, such as breast, pancreas, lung, and colon cancer (Anderson et al., 2005; Armstrong, Hutchinson, Unwin, & Fletcher, 2004; SCF, 2002; Xia et al., 2013). Some PAHs undergo metabolic activation to diol-epoxides, which are capable of binding covalently to DNA (Rengarajan et al., 2015). The U.S. Environmental Protection Agency (EPA) selected 16 priority PAHs based on their occurrence and carcinogenicity. In recent years, studies have found that benzo[a]pyrene is not a suitable marker for PAHs occurrence in foods, since it is not a good indicator of the concentration of other carcinogenic PAHs. Thus, the use of the sum of eight genotoxic PAHs, benzo[a]pyrene equivalents (BaPeq), as well as the sum of four PAHs, including benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene was recommended (Alomirah et al., 2010; EFSA, 2008; Purcaro, Moret, & Conte, 2013). Human beings are exposed to PAHs mostly through intake of  et al., food, apart from smoking and occupational exposure (Falco 2003; Martorell et al., 2010; Xia et al., 2010). Food contaminated with PAHs generally arises from environmental contamination, food processing, and direct contact with non-food grade mineral oil and contaminated packaging (Purcaro et al., 2013). Heating is an important cause for PAHs formation in food. A high PAHs level is

G. Li et al. / Food Control 59 (2016) 328e336

found in cooked foods after processes such as frying, smoking, grilling, and roasting (Farhadian, Jinap, Faridah, & Zaidul, 2012; Lin, , Martí-Cid, Castell, Weigel, Tang, Schulz, & Shen, 2011; Perello  Llobet, & Domingo, 2009; Skaljac et al., 2014). Youtiao, or oil stick, is a long golden-brown deep-fried stick of dough widely consumed in China. As a traditional breakfast food, youtiao is very popular with all ages of the population. Many reports have revealed the occurrence of PAHs in fried meats and French fries (Chen & Chen, 2003; Janoszka, 2011; Purcaro, Navas, Guardiola, Conte, & Moret, 2006). Very few studies, however, have examined the PAHs content in youtiao and dietary exposure due to its consumption. Moreover, the cancer risk assessment pertaining to PAHs in youtiao has been rarely investigated. Therefore, the objectives of this study were to 1) measure the concentration of the 16 USEPA priority PAHs in commercial and lab-made youtiao samples, 2) estimate the dietary exposure to PAHs through youtiao consumption in northern and southern China using Monte Carlo simulation, and 3) quantify the incremental lifetime cancer risk (ILCR) caused by PAHs dietary exposure from youtiao. Sensitivity and uncertainty analyses were conducted to identify the accuracy of critical input variables.

329

Table 1 The origins of youtiao samples. No.

Origin

Frying oils

1 2 3 4 5 6 7 8 9 10

Factory Restaurant Restaurant Cafeteria Cafeteria Supermarket Supermarket Supermarket Lab-made Lab-made

soybean soybean palm oil soybean soybean soybean soybean soybean soybean palm oil

a

oila oil oil oil oil oil oil oil

Samples obtained in factory are precooked frozen products.

Both the purchased and the lab-made youtiao samples were vacuum-dried (DZF-6020, Shanghai, China) at 60
C for 2 h after shearing into small pieces with a scissor. Approximately 100 g of dried sample was extracted with 350 ml of n-hexane in an ultrasound bath for 1 h. The oil sample was obtained after concentrating the extraction solution with a rotavapour (RE-52AA, Shanghai, China) at 40
C. The oil samples were placed in sealed glass bottles and stored in the dark at 4
C before use.

2. Materials and methods 2.3. Extraction and clean-up 2.1. Chemicals and materials All solvents used in this study were of HPLC grade. n-Hexane, acetonitrile, acetone, and dichloromethane were purchased from CNW Technologies GmbH (Darmstadt, Germany). Acetone, methanol, and toluene were obtained from Sinopharm Chemical Reagent Company (Shanghai, China). Water was purified with a Milli-Q water purification system (Millipore Co., Milford, USA). A standard mixture containing 16 PAHs (catalog no. 47940-U) with concentrations of 10 mg of each compound in 1 ml of acetonitrile was purchased from Supelco Inc. (Bellefonte, PA). This mixture contained the following PAHs: naphthalene (NA), acenaphthylene (Ap), acenaphthene (Ac), fluorine (F), anthracene (Ant), phanthrene (Phe), fluoranthene (Fl), pyrene (Pyr), benzo[a]anthracene (BaA), chrysene (Chr), benzo[k]fluoranthene (BkF), benzo[b]fluoranthene (BbF), benzo[a]pyrene (BaP), indeno[1,2,3-c,d]pyrene (Ip), dibenzo[a,h] anthracene (DBahA), benzo[g,h,i]perylene (BghiP). C18 solid phase extraction (SPE) cartridges (2 g, 12 ml) and Florisil SPE cartridges (1 g, 6 ml) were purchased from Supelco Inc. (Bellefonte, PA). 2.2. Sampling and sample preparation No. 1 to 8 youtiao samples were randomly purchased from eight different locations including food factories, popular chain restaurants, school cafeterias, and representative supermarkets in Shanghai, China, from the years 2012 to 2014. We collected 3e5 batches of samples from each location for analysis. Samples from each batch were mixed prior to analysis. No. 9 and 10 samples were prepared in the laboratory. Origins and frying oils of the samples are shown in Table 1. The ingredients for lab-made youtiao included 500 g of wheat flour, 8.5 g of salt, 9.5 g of sodium bicarbonate, 8.6 g of aluminum potassium sulfate, and 270 ml of deionized water. Solutions of salt, sodium bicarbonate, and aluminum potassium sulfate in deionized water were added to the flour. All ingredients were kneaded for 5e6 min to form a soft elastic structure and smooth skin. Then the dough was conditioned at 20
C for 4e6 h. After conditioning, the dough was rolled out and cut into pieces of 8 cm length and 2.5 cm width. Every two pieces were stacked, pressed on the center with a wooden rod, stretched to 25 cm long from both ends, and then deep-fried at 180
C for 130 s.

Sample extraction and clean-up were performed using the procedure reported by Wu and Yu (2012) with some modifications. Approximately 2.5 g of the oil sample was weighed into a stoppered centrifuge tube, and 10 ml acetonitrile/acetone mixture (3:2, v/v) was added. The sample was agitated for 30 s, ultra-sonicated for 5 min, and centrifuged at 2311 g for 5 min. The upper phase was collected in a new centrifuge tube. The extraction was repeated two more times, and the combined extracts were then concentrated to approximately 200e800 mg in a water bath at 35
C under a nitrogen flow. The concentrated oil residue was extracted again three more times with 2 ml acetonitrile/acetone mixture (3:2, v/v), shaken for 15 s and centrifuged for 30 s at 2311 g, and the top layer was transferred onto a C18 SPE cartridge, which had been activated with 2  12 ml of methanol and then 2  12 ml of acetonitrile. Another 5 ml acetonitrile/acetone (3:2, v/v) was eluted through the cartridge. All of the collected eluate was evaporated to approximately 50 mg under a stream of nitrogen and dissolved in 1 ml nhexane. Then the solution was transferred onto a Florisil SPE cartridge, which had been activated with 2  6 ml of dichloromethane and 2  6 ml of n-hexane. Another 5 ml n-hexane and 5 ml nhexane/dichloromethane (95:5, v/v) were eluted through the cartridge and discarded. The PAHs were then eluted with 5 ml of nhexane/dichloromethane (1:2, v/v). The eluate was concentrated under a nitrogen flow to approximately 20 ml and diluted with acetonitrile to 250 ml. The prepared samples were stored in the dark at 18
C before GC-MS analysis. Standards of different concentrations were added to the samples prior to extraction to estimate the recoveries. 2.4. GC-MS analysis of PAHs A gas chromatograph-mass spectrometer (Agilent 7890A5975C, USA) was used for analytical determination. Separation of compounds was performed on a DB-5MS capillary column (30 m  0.25 mm  0.25 mm) from J&W Scientific (Folsom, CA, USA). The column temperature was held at 80
C for 2 min, then increased to 140
C at 20
C/min, and then to 305
C at 3
C/min. The temperatures of injector, transfer line and ion source were set at 300, 280 and 230
C, respectively. Helium (purity > 99.999%) was used as carrier gas at a constant flow rate of 1 ml/min. The extract

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G. Li et al. / Food Control 59 (2016) 328e336

(1 ml) was injected with an autosampler in splitless mode. Electron impact ionization mass spectra were recorded with an ionization energy of 70 eV and multiplier voltage of 1506 V. Mass spectra were scanned from 33 to 400 amu for 0.4 s in total ion chromatogram (TIC) mode to identify the compounds in the standard mixtures and samples. Each compound was identified by comparison of its mass spectra with that of a standard compound, and by comparison to the NIST2011 mass spectral reference library (National Institute of Standards and Technology, Gaithersburg, MD, USA version 2011).

Table 3 Name, abbreviation, number of rings, and TEFs of the 16 PAHs.

2.5. Quality assurance/quality control The PAHs were quantified using an external standard method. The standard curve of each PAH was prepared by plotting the peak area against standard concentration (ng/ml), and the amount of each PAH was calculated on the basis of its respective calibration curve. The limits of detection (LOD) and quantitation (LOQ) were calculated by using the signal-to-noise ratio of S/N ¼ 3 and S/N ¼ 10, respectively. The average LOD of 16 PAHs ranged from 0.005 to 0.36 mg/kg. The method recovery was determined by spiking the samples with individual PAHs standards at three levels from 10 to 200 ng/ml in triplicate. Linear equations of the calibration curves and recoveries of 16 PAHs are shown in Table 2. The regression coefficient (R2) of the PAHs standard calibration curves covering the concentrations from 5 to 200 ng/ml ranged from 0.9893 to 0.9998. Average recoveries of 16 PAHs were in the range of 72e108%. 2.6. Dietary exposure estimation BaP has been considered to be one of the most potent carcinogenic and representative PAHs. Since different PAHs differ in their ability to produce a toxic effect, the toxicity equivalency factors (TEFs) are used to express the relative carcinogenic potency of each PAH compared to BaP, which is given a reference value of 1 (FAO/ WHO, 2006; Yoon, Park, Lee, Yang, & Lee, 2007). To assess the hazard of PAHs mixture, the BaP equivalent (BaPeq) concentration was obtained by multiplying the concentration of each PAH with its TEF as reported earlier (Nisbet & LaGoy, 1992) (Table 3). The BaPeq concentration was calculated according to Eq. (1):

X

BaPeqj ¼

n X

Ci  TEFi

(1)

i¼1

Name

Abbreviation

Number of rings

TEFsa

Naphthalene Acenaphthylene Acenaphthene Fluorine Anthracene Phanthrene Fluoranthene Pyrene Benzo[a]anthracene Chrysene Benzo[k]fluoranthene Benzo[b]fluoranthene Benzo[a]pyrene Indeno[1,2,3-c,d]pyrene Dibenzo[a,h]anthracene Benzo[g,h,i]perylene

NA Ap Ac F Ant Phe Fl Pyr BaA Chr BkF BbF BaP Ip DBahA BghiP

2 3 3 3 3 3 4 4 4 4 5 5 5 6 5 6

0.001 0.001 0.001 0.001 0.01 0.001 0.001 0.001 0.1 0.01 0.1 0.1 1 0.1 5 0.01

a

Nisbet and LaGoy (1992).

P Where BaPeqj is the concentration of BaPeq in youtiao obtained from location j (mg/kg); Ci is the concentration of PAH congener i (mg/kg); TEFi is the TEF of PAH congener i. To quantify the dietary exposure to PAHs, we assumed that each location had approximately the same amount of consumption due to the absence of location data on the consumption distribution. We also believed that the PAHs concentration in youtiao purchased from Shanghai represented the national levels. For one reason, youtiao is widely consumed and available everywhere in Shanghai; for another, the population in Shanghai represents both the diversity and quantity of the China's population. According to the latest data recently released by the local statistical bureau, the number of Shanghai's permanent residents stood at 24.2568 million at the end of 2014, including 14.2926 million registered permanent residents and 9.9642 million non-registered migrants from other regions of China. Exposure estimates were performed in four age groups: children (2e10 years old), adolescents (11e17 years old), adults (18e60 years old), and seniors (61e70 years old). The daily dietary exposure (ED) to PAHs from youtiao for each age group was calculated by Eq. (2), based on Wu, Zhang, Zhang, and Cheng (2011) method.

P ED ¼

BaPeq  IR  EF  ED BW  AT

(2)

Table 2 Retention time, quantifier ion, linear equation and mean recovery of the 16 PAHs analyzed by GC-MS. PAHs

NA Ap Ac F Ant Phe Fl Pyr BaA Chr BkF BbF BaP Ip DBahA BghiP

Retention time (min)

6.48 10.55 11.23 13.52 18.79 19.10 26.79 28.29 37.41 37.64 45.03 45.22 47.03 53.72 54.07 55.05

Quantifier ion (m/z)

128 152 154 166 178 178 202 202 228 228 252 252 252 276 278 276

Linear equation

Average recovery (%)

Slop

Intercept

R2

304.39 225.36 150.08 175.23 229.72 149.00 181.14 189.95 80.287 119.93 105.57 98.679 57.215 91.585 36.121 73.114

2930.8 430.75 566.99 2367.5 4649.6 676.97 1156.5 1190.4 274.10 622.24 1209.3 968.14 142.89 2803.2 61.428 116.75

0.9992 0.9990 0.9997 0.9988 0.9998 0.9987 0.9993 0.9987 0.9956 0.9938 0.9968 0.9957 0.9993 0.9893 0.9987 0.9998

80.88 81.71 82.40 72.17 86.68 79.68 79.37 108.08 78.95 75.89 92.23 85.71 75.02 85.09 80.74 88.87

G. Li et al. / Food Control 59 (2016) 328e336

ED is the chronic daily dietary exposure of BaPeq through youtiao P consumption ng/(kg$day); BaPeq is the average concentration of BaPeq in youtiao (mg/kg); IR is the ingestion amount of youtiao per day (g/day); EF is the exposure frequency, in this study, 365 days/ year; ED is the exposure duration (year); BW is the body weight (kg); and AT is the average lifespan (day), 25,550 days (USEPA, 1997; P Wu et al., 2011; Xia et al., 2010). We took BaPeq, IR and BW to follow approximately lognormal distribution, and ED to follow a uniform distribution in the range of 0e9, 0e7, 0e43 and 0e10 years for children, adolescents, adults and seniors, respectively. The daily ingestion amount (IR) and body weight (BW) (Table 4) were obtained from the data of 2002 Chinese National Health and Nutrition Survey (Jin, 2008). In that survey, assessment of the dietary intake was based on a 24 h recall method for 3 days through a multi-stage stratified cluster random sampling from 68,959 consumers nationwide in metropolis, middle and small sized city, and different rural areas. The north and south of China, which are divided by the Yangtze River, have different dietary habits according to that survey. 2.7. Health risk estimation The incremental lifetime cancer risk (ILCR) associated with dietary exposure of PAHs in youtiao was calculated by Eq. (3) based on Wu et al. (2011) method:

ILCR ¼ ED  SF  CF

(3)

ILCR is the additional probability of human cancer over a lifetime; SF is the oral cancer slop factor, which obeys lognormal distribution with a geometric mean of 7.3 per [mg/(kg$day)] (Xia et al., 2010); CF is the conversion factor (106 mg/ng). 2.8. Uncertainty analysis Monte Carlo simulation was applied to evaluate the uncertainties in the dietary exposure and risk estimation. The simulations were run for 10,000 iterations to ensure the stability of results with each input values randomly selected from their respective probability distributions. Sensitivity analysis was used to determine the extent of the influence of each input parameter on the estimated results. We evaluated the sensitivity by calculating Spearman's rank correlation coefficients between each input and output values and then squaring the output variance and normalizing to 100%. The Monte Carlo simulation and sensitivity analysis were implemented using MATLAB 7.10.0.499 (R2010a). 2.9. Statistical analysis Each analysis was conducted in triplicate (n ¼ 3). The statistical calculations (significance level a ¼ 0.05) were performed using SPSS 22.0 software (SPSS, Chicago, USA) and results were expressed as means ± standard deviations.

331

3. Results and discussion 3.1. Concentration of PAHs in youtiao BaP was used as a marker for the occurrence and effect of carcinogenic PAHs in food based on the opinion of Scientific Committee on Food (SCF) in December 2002 (SCF, 2002). The SCF also recommended that further analysis of the suitability of maintaining BaP as a marker would be necessary. The European Commission Regulation (EC) No 1881/2006 sets a maximum limit for only BaP in a range of foodstuffs (European Commission, 2006). In 2008, after taking into account the new occurrence data collected by the Member States, the European Food Safety Authority (EFSA) concluded that BaP is not a suitable marker for the occurrence of PAHs in food and that a system of PAH4 (BaA, Chr, BbF, and BaP) or PAH8 (BaA, Chr, BkF, BbF, BaP, Ip, DBahA, and BghiP) would be more suitable indicators of PAHs in food (EFSA, 2008). In 2011, Regulation (EC) No 835/2011 (European Commission, 2011), amending Regulation (EC) No 1881/2006, introduced new maximum levels for the sum of 4 substances (PAH4), and a separate maximum level for BaP was also maintained. For instance, oils and fats complied with the maximum levels of 2.0 mg/kg for BaP and 10.0 mg/kg for PAH4. In processed cereal-based foods, a 1.0 mg/kg limit for both the BaP and the sum of PAH4 was introduced (European Commission, 2011). Table 5 shows the detailed concentrations of 16 USEPA priority PAHs in youtiao samples from different origins. The sum concentrations of low molecular weight (LMW) PAHs, high molecular weight (HMW) PAHs, PAH4, PAH8, total PAHs, and BaPeq for all the analyzed samples are also given. It can be noted that youtiao samples showed significant differences in PAHs concentrations across diverse origins. To the best of our knowledge, this study is the first report on the levels of PAHs in youtiao. The highest level of total PAHs was detected in sample 7 (89.97 mg/kg), followed by sample 4 (64.77 mg/kg) and sample 5 (58.25 mg/kg). By contract, the lowest concentration of total PAHs was found in sample 10 (9.90 mg/ kg), sample 9 (10.84 mg/kg) and sample 1 (27.30 mg/kg). Carcinogenic PAHs, expressed as BaPeq, ranged from 1.08 to 27.96 mg/kg. In particular, sum concentrations of PAH4 were between 1.41 and 26.56 mg/kg. All of the ten samples exceeded the legal limits (1 mg/ kg) proposed by the European Commission (2011) for processed cereal-based foods. Percentile concentrations of PAHs obtained from Monte Carlo simulation were shown in Table 6. The median concentrations of BaP, PAH4, PAH8, total PAHs and BaPeq were 1.50 mg/kg, 11.12 mg/kg, 16.35 mg/kg, 44.80 mg/kg and 5.92 mg/kg, respectively. It is worth mentioning that sample 1 was a semi-processed frozen product, which may require shorter frying time and lower frying temperature. Therefore, among the eight commercial youtiao samples, the lowest concentrations of BaP (0.75 mg/kg), PAH8 (8.72 mg/kg), total PAHs (27.30 mg/kg) and BaPeq (1.51 mg/kg) were all detected in sample 1. By the same token, both the two lab-made samples had mean concentrations of BaP, PAH4, PAH8 and total PAHs relatively lower than that of the commercially available

Table 4 Body weight and ingestion amount of youtiao of different population groups in China. Population group

Age (years)

Body weight (kg)

Children Adolescents Adults Seniors

2e10 11e17 18e60 61e70

25.32 49.14 61.59 60.33

Daily ingestion amount of youtiao (g/day) North

± ± ± ±

4.33 8.44 11.52 11.22

3.04 4.98 5.68 4.64

± ± ± ±

South 1.58 2.60 2.96 2.42

0.84 1.37 1.56 1.27

± ± ± ±

Nation 0.44 0.71 0.81 0.66

The data was obtained from 2002 Chinese National Health and Nutrition Survey (Jin, 2008). The data are presented as means ± standard deviations.

1.88 3.08 3.50 2.86

± ± ± ±

0.98 1.60 1.83 1.49

332

G. Li et al. / Food Control 59 (2016) 328e336

Table 5 Concentrations (n ¼ 3) of 16 PAHs in ten different youtiao samples (means ± standard deviations). PAHs

PAHs concentration (mg/kg wet mass) 1

NA Ap Ac F Ant Phe Fl Pyr BaA Chr BkF BbF BaP Ip DBahA BghiP

3.72 0.22 0.71 2.23 5.28 0.86 2.33 3.23 3.79 2.24 1.34 0.37 0.75 0.21 0.02 e

a

LMW PAHs HMW PAHsb PAH4c PAH8d Total PAHs BaPeq a

c d

± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.47 0.02 0.13 0.28 0.36 0.06 0.11 0.23 0.21 0.04 0.73 0.16 0.43 0.21 0.04

9.43 0.42 1.50 4.35 9.20 1.54 4.13 5.75 5.74 2.66 2.90 7.93 1.61 0.62 0.22 e

3 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.30 0.02 0.02 0.07 0.45 0.10 0.24 0.30 0.41 0.02 0.10 0.13 0.14 0.06 0.11

6.80 0.31 0.98 3.20 7.17 1.17 3.33 4.47 3.95 1.86 1.81 4.67 0.96 0.31 0.24 e

4 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.00 0.00 0.06 0.06 0.23 0.06 0.17 0.17 0.47 0.16 0.24 0.49 0.20 0.08 0.10

7.18 0.39 1.28 4.26 11.02 1.63 4.53 5.52 6.73 4.14 8.52 4.45 2.81 1.32 0.99 e

5 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

1.41 0.04 0.23 0.43 1.48 0.24 0.81 1.05 0.82 1.30 1.60 1.71 0.47 0.90 0.53

7.85 0.53 1.38 4.87 12.14 1.75 4.89 6.42 6.76 5.30 3.13 1.24 1.42 0.40 0.17 e

6 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.55 0.04 0.02 0.50 1.82 0.29 0.77 0.74 0.66 0.71 0.26 0.11 0.04 0.09 0.11

6.28 0.23 1.22 3.50 7.02 0.88 2.36 5.81 3.18 1.95 3.34 0.76 1.17 0.64 0.69 0.49

7 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.08 0.01 0.06 0.12 0.21 0.01 0.05 0.19 0.13 0.03 0.99 0.31 0.02 0.31 0.53 0.33

8.93 0.34 2.01 6.56 12.13 1.64 4.39 9.04 11.00 7.26 7.75 3.09 5.21 4.67 3.97 1.98

8 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

1.72 0.08 0.62 1.92 3.44 0.45 1.16 2.46 2.66 2.12 0.48 0.39 0.06 0.27 0.00 0.11

8.14 0.22 1.32 3.41 7.11 0.90 2.06 5.48 4.08 2.38 3.10 0.42 1.28 0.65 0.6 0.37

9 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.11 0.03 0.09 0.22 0.51 0.22 0.15 0.38 0.48 0.49 0.58 0.15 0.07 0.41 0.38 0.24

10

1.31 0.13 0.27 0.99 2.76 0.46 1.09 0.79 0.43 0.63 0.56 0.23 0.47 0.29 0.17 0.28

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.12 0.02 0.03 0.11 0.33 0.09 0.35 0.21 0.15 0.39 0.25 0.08 0.14 0.05 0.07 0.08

1.33 0.13 0.26 0.97 2.22 0.49 0.89 0.85 0.42 0.34 0.41 0.20 0.45 0.31 0.09 0.54

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

0.10 0.01 0.01 0.11 0.20 0.03 0.02 0.04 0.04 0.03 0.06 0.06 0.06 0.12 0.03 0.11

PAHs concentration (mg/kg)

PAHs

b

2

1

2

3

4

5

6

7

8

9

10

24.61 2.69 7.15 8.72 27.30 1.51

44.72 13.28 17.94 21.68 58.00 4.57

33.24 7.99 11.44 13.8 41.23 3.34

46.68 18.09 18.13 28.96 64.77 10.04

51.89 6.36 14.72 18.42 58.25 3.63

32.43 7.09 7.06 12.22 39.52 5.53

63.30 26.67 26.56 44.93 89.97 27.96

35.10 6.42 8.16 12.88 41.52 5.23

8.85 1.99 1.75 3.05 10.84 1.53

7.91 2.00 1.41 2.76 9.90 1.08

LMW (Low Molecular Weight) PAHs include the sum of NA, Ap, Ac, F, Ant, Phe, Fl, Pyr, BaA, and Chr. HMW (High Molecular Weight) PAHs include the sum of BkF, BbF, BaP, Ip, DBahA, and BghiP. PAH4 includes the sum of BaA, Chr, BbF, and BaP. PAH8 includes the sum of BaA, Chr, BkF, BbF, BaP, Ip, DBahA, and BghiP.

samples. Kao, Chen, Chen, Huang, and Chen (2012) also found a larger amount of total PAHs (79.7 mg/kg) in duck drumstick fried for 15 min, comparing to chicken drumstick (54.8 mg/kg) fried for 12 min, due to the longer frying time of the former. Cereals and cereal products were identified as important contributors to PAHs dietary exposure due to their high consumption (EFSA, 2008). Therefore, the PAHs levels in these foodstuffs should be given more attention. Orecchio and Papuzza (2009) reported that, in samples of bread baked using wood as fuel, the mean concentrations of BaPeq and total PAHs were 7.2 and 76 mg/kg, respectively, which were slightly higher than our data in youtiao. The large presence of PAHs in the bread samples was primarily attributed to the combustion processes according to the PAHs distribution indexes. High levels of PAHs were also observed by Ahmed, Abdel Hadi, El Samahy, and Youssof (2000) in bread produced from heavy oil, light oil, solid waste and electricity fueled bakeries, with average total PAHs concentrations of 320.6, 158.4, 317.3 and 25.5 mg/kg, respectively. Youtiao is a deep-fried flour-based food. The high levels of PAHs detected in youtiao samples were probably a consequence of high-

temperature processing and PAHs contamination of oils and raw materials. The PAHs in youtiao might be formed by a series of  et al. thermal reactions of material and oil during frying. Perello (2009) measured the levels of 16 individual PAHs in various foodstuffs and cooking methods. In general, the highest concentrations of PAHs were found after frying comparing to grilling, roasting and boiling. The concentrations of total PAHs in loin of pork, chicken, lamb and potato, respectively, were 4.47, 4.51, 5.47 and 2.01 mg/kg in raw samples, and 21.45, 14.96, 16.91 and 28.69 mg/kg in fried samples. Besides, many authors have reported the contaminations of PAHs in edible oils. For example, 5.17 and 14.16 mg/kg of sum of 16 USEPA priority PAHs were found in soybean oil and palm oil by Alomirah et al. (2010), and 3.63, 3.85 and 11.8 mg/kg of PAH4 were found in soybean oil, olive oil and rapeseed oil by Drabova et al. (2013), which may lead to the PAHs contamination of deep-fried food. Moreover, the amount of PAHs was largely related to the fat content in food (Gomes, Santos, Almeida, Elias, & Roseiro, 2013; Saito, Tanaka, Miyazaki, & Tsuzaki, 2014). Ring distributions of PAHs from different youtiao samples are presented in Fig. 1. For the ten youtiao samples in this study, 3- and

Table 6 Cumulative probability of PAHs concentrations in youtiao. Percentile

5th 25th 50th 75th 95th a b c d

PAHs (mg/kg wet mass) 16 PAHs

LMW PAHsa

HMW PAHsb

PAH8c

PAH4d

BaP

BaPeq

36.50 40.69 43.80 47.22 52.61

28.55 32.04 34.66 37.42 42.01

5.47 7.29 8.89 10.82 14.17

11.61 14.18 16.35 18.78 23.10

7.55 9.48 11.12 13.05 16.35

0.81 1.16 1.50 1.93 2.81

3.00 4.50 5.92 7.85 11.57

LMW (Low Molecular Weight) PAHs include the sum of NA, Ap, Ac, F, Ant, Phe, Fl, Pyr, BaA, and Chr. HMW (High Molecular Weight) PAHs include the sum of BkF, BbF, BaP, Ip, DBahA, and BghiP. PAH8 includes the sum of BaA, Chr, BkF, BbF, BaP, Ip, DBahA, and BghiP. PAH4 includes the sum of BaA, Chr, BbF, and BaP.

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4-ring PAHs were the dominant components, which accounted for 60.4e76.5% of the total PAHs. Moreover, 5- and 6-ring PAHs, which are more toxic than low molecular weight PAHs, made up 9.85e29.6% of the total PAHs. In particular, the lowest percentage of 5- and 6- PAHs (9.85%) was detected in sample 1, the semiprocessed frozen product. This result is consistent with that of Saito et al. (2014), who also reported that the high temperature achieved when grilling food would cause the formation of higher molecular weight PAHs. 3.2. Dietary exposure estimation Daily dietary exposure to PAHs for each population group in China was calculated through Eqs. (1) and (2). Monte Carlo simulation was applied to evaluate the uncertainties of output values. Fig. 2 shows the cumulative probability of dietary BaPeq exposure obtained from Monte Carlo simulation. In the present study, the estimated dietary exposure to PAHs was based only on consumption of youtiao. Due to differences in dietary habits, the average consumption level of flour and flour-based food in northern China was significantly higher than that in the south. The median dietary exposure of BaPeq concentrations from youtiao for children, adolescents, adults and seniors in northern China, respectively, were 0.0247, 0.0169, 0.0928 and 0.0177 ng/(kg$day). The exposure doses in the north were approximately 4.13 times higher than that for consumers in southern China. For the national scale consumers, the median dietary exposure of BaPeq concentrations were 0.0147, 0.0101, 0.0561 and 0.0106 ng/(kg$day) for children, adolescents, adults and seniors, respectively. Similar results were reported by Alomirah et al. (2011) who reported that the mean daily dietary exposure of BaPeq concentrations from 60 kinds of grilled and smoked food items in Kuwait was 14.8 ng/day for children/ adolescent, and 16.8 ng/day for adult population. If considering the body weight and exposure time, the mean dietary BaPeq exposure for children/adolescent and adults were calculated to be 0.0414 and 0.0743 ng/(kg$day), respectively, which were very close to our exposure estimation results from youtiao. However, it should be pointed out that in Chinese dietary habits, especially in the northern China area, such as Tianjin, Shandong, youtiao is a common breakfast food. As shown in Fig. 2, the 95th percentile exposure of BaPeq concentrations was 6.80e8.87 times higher than the median values, indicating that the daily intakes of PAHs for these frequent youtiao consumers would be considerably more than the average data. What's more, other types of foods containing PAHs were not taken into account in this daily intake estimation.

Fig. 1. Ring distribution of PAHs in different youtiao samples.

Fig. 2. Cumulative probability of dietary BaPeq exposure from youtiao in China. A: north; B: south; C: national scale.

Several studies have been carried out to determine the level of dietary exposure to PAHs in human total diet. In Taiyuan, China, the median dietary exposure of BaPeq concentrations were reported to be 392.42, 511.01, 571.56, 532.56 ng/day for children, adolescents, adults and seniors of male, and 355.16, 440.51, 487.64, 444.85 ng/ day for the above groups of female, respectively (Xia et al., 2010). Wheat, in particular, made the greatest contribution (48.30e53.47%) to the PAHs exposure, followed by pork (10.45e12.49%) and fish (6.90e8.03%). In Korea, The time-weighted average exposure of BaPeq were found to be 6.82, 3.90, 2.83, 2.03 ng/kg bw/day for the 1e6, 7e19, 20e64, 65e73 age group, respectively (Yoon et al., 2007). In that research, the highest contributor to PAHs exposure in that study was estimated to be cereals, followed by vegetables and milk. In Catalonia, Spain, the dietary intakes of the sum of 16 PAHs were estimated to be 0.252 (boys), 0.227 (girls), 0.148 (adolescents-boys), 0.106 (adolescentsgirls), 0.096 (male adults), 0.071 (female adults), 0.055 (male

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seniors), and 0.045 mg/kg of body wt/day (female seniors) (Martorell et al., 2010). Based on the above reported data, the notable differences in dietary exposure to PAHs from different countries could be explained by the differences of PAHs concentrations in foods and different dietetic habits. 3.3. Health risk estimation Depending on the dietary exposure of BaPeq from youtiao and the cancer slope factors of BaP, the incremental lifetime cancer risk (ILCR) was established to estimate the additional probability of human cancer over an average lifespan of 70 years. The cumulative probability distributions of ILCR for different age and region population groups in China are shown in Fig. 3. The results indicated that the dietary ILCRs for children, adolescents, adults and seniors age groups in northern China followed lognormal (LN) distributions of LN (1.46  107, 4.45), LN (9.99  108, 4.27), LN (5.45  107, 4.38) and LN (1.06  107, 4.34), respectively. For the population in national scale, the dietary ILCRs were estimated to be LN (8.71  108, 4.57), LN (5.96  108, 4.42), LN (3.33  107, 4.39) and LN (6.38  108, 4.37), for children, adolescents, adults and seniors, respectively. Under most regulatory programs, an ILCR of 106 or less denotes the level of risk considered acceptable and inconsequential, an ILCR greater than 104 denotes serious risk, and an ILCR between 106 and 104 denotes potential risk (Chen & Liao, 2006; Wang et al., 2011; Xia et al., 2013). Our results showed that the median value of ILCR for each age group had orders of magnitude around 107 and 108 (Fig. 3). However, the 95th percentile dietary ILCRs for children group in northern China, and adults group in both north and south, exceeded the 106 limit, which were 1.33  106, 4.79  106 and 1.34  106, respectively. For adults group in the north particularly, the cumulative probabilities of ILCRs exceeding 1  106 and 1  105 were 63.36% and 98.82%, respectively, which indicated a slight potential carcinogenic risk. The potential carcinogenic risk from youtiao consumption may be due to the fact that many youtiao makers, such as private vendors or fast-food restaurants, lack good manufacturing practice, resulting in higher PAHs content. It is necessary to take appropriate measures to control the health risk due to dietary PAHs exposure from youtiao. For four age groups, adults had the highest carcinogenic risk, followed by children, seniors and adolescents. This result was consistent with other three reports by Xia et al. (2010), Wu et al. (2011) and Ding, Ni, and Zeng (2013). Adults contributed the most to the cancer risk in the lifetime, which could be attributed to the longest exposure duration and the highest ingestion amount of youtiao. Although the ingestion amount of children was lower than that of seniors and adolescents, the body weight of children was also significantly lower, resulting in a high risk value for children. 3.4. Sensitivity analysis A quantitative sensitivity analysis was conducted during Monte Carlo simulation to further evaluate the impact of variation of parameters on the ILCR by exposure to PAHs. The sensitivity analysis results from a national scale were shown in the form of the normalized Spearman's rank correlation coefficient (Fig. 4). The results of the analysis indicated that the BaPeq concentration, exposure duration (ED), ingestion rate (IR) and cancer slop factor (SF) were the most influential variables for all the four age groups. Therefore, more efforts should focus on improving the accuracy of probability distributions of the above four parameters (BaPeq, ED, IR, SF) to obtain a better estimate. In addition to uncertainty and sensitivity analysis results obtained from Monte Carlo simulation, there were still other

Fig. 3. Probabilistic incremental lifetime cancer risk of PAHs from youtiao in China. A: north; B: south; C: national scale.

uncertainties in the process of risk estimation. Due to the absence of data on the consumption distribution of youtiao from different locations, we assumed that each location had approximately the same amount of consumption, and the PAHs concentration in youtiao purchased from Shanghai represented the national levels, which might cause the uncertainties of BaPeq exposure. The parameters of body weight (BW) and ingestion amount (IR) were based on the data of the Chinese National Health and Nutrition Survey in 2002, which might be changed over the past decade. Moreover, the PEFs and SF values were calculated on the basis of results of animal experiment, which might not be applicable to human exactly (Wu et al., 2011). Considering that some PAHs are both genotoxic and carcinogenic, showing non-linear doseeresponse relationships, it is difficult to establish health-based guidance values for those compounds (FAO/WHO, 2006). The advice given by JECFA has been that intakes should be reduced to as low as reasonably achievable (ALARA) (FAO/WHO, 2006). Therefore, it would be inappropriate to build a safety level for youtiao consumption based on PAHs exposure.

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Fig. 4. Sensitivity analysis of incremental lifetime cancer risk from a national scale. A: children; B: adolescents; C: adults; D: seniors.

However, a safety level of 255 g/week for adults and 140 g/week for children have been established on the basis of the mean aluminum content (429.7 mg/kg) of youtiao and Provisional Tolerable Weekly Intake (PTWI) (CFSA, 2012). The health risk estimation of youtiao in the present study was only based on exposure to PAHs. Other compounds that threaten our health in youtiao, such as aluminum and acrylamide, should be taken into account when conducting an overall risk assessment. 4. Conclusion This study reported the PAHs levels in different youtiao samples for the first time. All of the ten youtiao samples exceeded the legal limits (1 mg/kg for the sum of PAH4) proposed by the European Commission for processed cereal-based foods. The median dietary exposure of BaPeq concentrations from youtiao for children, adolescents, adults and seniors in China, respectively, were 0.0147, 0.0101, 0.0561 and 0.0106 ng/(kg$day). However, the daily intakes of PAHs for frequent youtiao consumers would be considerably more than the average data. The 95th percentile incremental lifetime cancer risk (ILCR) for children group in northern China, and adults group in both north and south, indicated a slight potential carcinogenic risk due to PAHs contamination in youtiao. Acknowledgments This study was supported by the National Natural Science Foundation of China (Nos. 31171704 and 31471668). References Ahmed, M. T., Abdel Hadi, E. S., El Samahy, S., & Youssof, K. (2000). The influence of baking fuel on residues of polycyclic aromatic hydrocarbons and heavy metals in bread. Journal of Hazardous Materials, 80(1), 1e8. Alomirah, H., Al-Zenki, S., Al-Hooti, S., Zaghloul, S., Sawaya, W., Ahmed, N., et al. (2011). Concentrations and dietary exposure to polycyclic aromatic hydrocarbons (PAHs) from grilled and smoked foods. Food Control, 22(12), 2028e2035. Alomirah, H., Al-Zenki, S., Husain, A., Sawaya, W., Ahmed, N., Gevao, B., et al. (2010). 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. Food Additives and Contaminants, 27(6), 869e878. Anderson, K. E., Kadlubar, F. F., Kulldorff, M., Harnack, L., Gross, M., Lang, N. P., et al. (2005). Dietary intake of heterocyclic amines and benzo (a) pyrene: associations with pancreatic cancer. Cancer Epidemiology Biomarkers & Prevention, 14(9), 2261e2265. Armstrong, B., Hutchinson, E., Unwin, J., & Fletcher, T. (2004). Lung cancer risk after exposure to polycyclic aromatic hydrocarbons: a review and meta-analysis. Environmental Health Perspectives, 112, 970e978. CFSA, China National Center for Food Safety Risk Assessment. (2012). Risk assessment of dietary exposure to aluminum in Chinese population. Technical Report of China National Expert Committee on Food Safety Risk Assessment, No. 2011e002 (in Chinese). Chen, Y. C., & Chen, B. H. (2003). Determination of polycyclic aromatic hydrocarbons in fumes from fried chicken legs. Journal of Agricultural and Food Chemistry, 51(14), 4162e4167. Chen, S. C., & Liao, C. M. (2006). Health risk assessment on human exposed to environmental polycyclic aromatic hydrocarbons pollution sources. Science of the Total Environment, 366(1), 112e123. Ding, C., Ni, H. G., & Zeng, H. (2013). Human exposure to parent and halogenated polycyclic aromatic hydrocarbons via food consumption in Shenzhen, China. Science of the Total Environment, 443, 857e863. Drabova, L., Tomaniova, M., Kalachova, K., Kocourek, V., Hajslova, J., & Pulkrabova, J. (2013). Application of solid phase extraction and two-dimensional gas chromatography coupled with time-of-flight mass spectrometry for fast analysis of polycyclic aromatic hydrocarbons in vegetable oils. Food Control, 33(2), 489e497. EFSA, European Food Safety Authority. (2008). Polycyclic aromatic hydrocarbons in food: Scientific opinion of the Panel on Contaminants in the Food Chain. The EFSA Journal, 724, 1e114. European Commission. (2006). European Commission Regulation (EC) No 1881/ 2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union, L364, 5e24. European Commission. (2011). European Commission Regulation (EC) No 835/2011 of 19 August 2011 amending Regulation (EC) No 1881/2006 as regards maximum levels for polycyclic aromatic hydrocarbons in foodstuffs. Official Journal of the European Union, L215, 4e8. , G., Domingo, J. L., Llobet, J. M., Teixido , A., Casas, C., & Müller, L. (2003). Falco Polycyclic aromatic hydrocarbons in foods: human exposure through the diet in Catalonia, Spain. Journal of Food Protection, 66(12), 2325e2331. FAO/WHO. (2006). Evaluation of certain food contaminants. Sixty-fourth report of the Joint FAO/WHO Export Committee on Food Additives. Geneva: World Health Organization. WHO Technical Report Series, No. 930; http://whqlibdoc.who.int/ trs/WHO_TRS_930_eng.pdf. Farhadian, A., Jinap, S., Faridah, A., & Zaidul, I. S. M. (2012). Effects of marinating on the formation of polycyclic aromatic hydrocarbons (benzo[a]pyrene, benzo[b] fluoranthene and fluoranthene) in grilled beef meat. Food Control, 28(2), 420e425. Gomes, A., Santos, C., Almeida, J., Elias, M., & Roseiro, L. C. (2013). Effect of fat content, casing type and smoking procedures on PAHs contents of Portuguese

336

G. Li et al. / Food Control 59 (2016) 328e336

traditional dry fermented sausages. Food and Chemical Toxicology, 58, 369e374. Janoszka, B. (2011). HPLC-fluorescence analysis of polycyclic aromatic hydrocarbons (PAHs) in pork meat and its gravy fried without additives and in the presence of onion and garlic. Food Chemistry, 126(3), 1344e1353. Jin, S. G. (2008). Chinese national health and nutrition survey report ten: 2002 nutrition and health status data set (in Chinese). Beijing: People's Medical Publishing House. Kao, T. H., Chen, S., Chen, C. J., Huang, C. W., & Chen, B. H. (2012). Evaluation of analysis of polycyclic aromatic hydrocarbons by the QuEChERS method and gas chromatography-mass spectrometry and their formation in poultry meat as affected by marinating and frying. Journal of Agricultural and Food Chemistry, 60(6), 1380e1389. Lin, G. F., Weigel, S., Tang, B., Schulz, C., & Shen, J. H. (2011). The occurrence of polycyclic aromatic hydrocarbons in Peking duck: Relevance to food safety assessment. Food Chemistry, 129(2), 524e527. , G., Martí-Cid, R., Castell, V., Llobet, J. M., & Domingo, J. L. (2010). Martorell, I., Perello Polycyclic aromatic hydrocarbons (PAH) in foods and estimated PAH intake by the population of Catalonia, Spain: temporal trend. Environment International, 36(5), 424e432. Nisbet, I. C., & LaGoy, P. K. (1992). Toxic equivalency factors (TEFs) for polycyclic aromatic hydrocarbons (PAHs). Regulatory Toxicology and Pharmacology, 16(3), 290e300. Orecchio, S., & Papuzza, V. (2009). Levels, fingerprint and daily intake of polycyclic aromatic hydrocarbons (PAHs) in bread baked using wood as fuel. Journal of Hazardous Materials, 164(2), 876e883.  , G., Martí-Cid, R., Castell, V., Llobet, J. M., & Domingo, J. L. (2009). ConcenPerello trations of polybrominated diphenyl ethers, hexachlorobenzene and polycyclic aromatic hydrocarbons in various foodstuffs before and after cooking. Food and Chemical Toxicology, 47(4), 709e715. ~ os, P., Frenich, A. G., & Vidal, J. L. M. (2010). Polycyclic aromatic hydroPlaza-Bolan carbons in food and beverages. Analytical methods and trends. Journal of Chromatography A, 1217(41), 6303e6326. Purcaro, G., Moret, S., & Conte, L. S. (2013). Overview on polycyclic aromatic hydrocarbons: occurrence, legislation and innovative determination in foods. Talanta, 105, 292e305. Purcaro, G., Navas, J. A., Guardiola, F., Conte, L. S., & Moret, S. (2006). Polycyclic aromatic hydrocarbons in frying oils and snacks. Journal of Food Protection, 69(1), 199e204.

Rengarajan, T., Rajendran, P., Nandakumar, N., Lokeshkumar, B., Rajendran, P., & Nishigaki, I. (2015). Exposure to polycyclic aromatic hydrocarbons with special focus on cancer. Asian Pacific Journal of Tropical Biomedicine, 5(3), 182e189. Saito, E., Tanaka, N., Miyazaki, A., & Tsuzaki, M. (2014). Concentration and particle size distribution of polycyclic aromatic hydrocarbons formed by thermal cooking. Food Chemistry, 153, 285e291. SCF, Scientific Committee on Food. (2002). Opinion of the Scientific Committee on Food on the risks to human health of Polycyclic Aromatic Hydrocarbons in Food. 4 December 2002. Brussels: European Commission (EC).  Skaljac, S., Petrovi c, L., Tasi c, T., Ikoni c, P., Jokanovi c, M., Tomovi c, V., et al. (2014). Influence of smoking in traditional and industrial conditions on polycyclic ar klob omatic hydrocarbons content in dry fermented sausages (Petrovska asa) from Serbia. Food Control, 40, 12e18. USEPA. (1997). Exposure factors handbook. EPA/600/8e89/043. Washington, D.C: Office of Research and Development, National Center for Environmental Assessment, U.S. Environmental Protection Agency. Available online at: http:// www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/documents/EFH_ Final_1997_EPA600P95002Fa.pdf. Wang, W., Huang, M. J., Kang, Y., Wang, H. S., Leung, A. O., Cheung, K. C., et al. (2011). Polycyclic aromatic hydrocarbons (PAHs) in urban surface dust of Guangzhou, China: status, sources and human health risk assessment. Science of the Total Environment, 409(21), 4519e4527. Wu, S., & Yu, W. (2012). Liquid-liquid extraction of polycyclic aromatic hydrocarbons in four different edible oils from China. Food Chemistry, 134(1), 597e601. Wu, B., Zhang, Y., Zhang, X. X., & Cheng, S. P. (2011). Health risk assessment of polycyclic aromatic hydrocarbons in the source water and drinking water of China: quantitative analysis based on published monitoring data. Science of the Total Environment, 410, 112e118. Xia, Z., Duan, X., Qiu, W., Liu, D., Wang, B., Tao, S., et al. (2010). Health risk assessment on dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in Taiyuan, China. Science of the Total Environment, 408(22), 5331e5337. Xia, Z., Duan, X., Tao, S., Qiu, W., Liu, D., Wang, Y., et al. (2013). Pollution level, inhalation exposure and lung cancer risk of ambient atmospheric polycyclic aromatic hydrocarbons (PAHs) in Taiyuan, China. Environmental Pollution, 173, 150e156. Yoon, E., Park, K., Lee, H., Yang, J. H., & Lee, C. (2007). Estimation of excess cancer risk on timeeweighted lifetime average daily intake of PAHs from food ingestion. Human and Ecological Risk Assessment, 13(3), 669e680.