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Dietary exposure of acrylamide from the fifth Chinese Total Diet Study
Food and Chemical Toxicology 87 (2016) 97e102
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Food and Chemical Toxicology journal homepage: www.elsevier.com/locate/foodchemtox
Dietary exposure of acrylamide from the fifth Chinese Total Diet Study Jie Gao a, Yunfeng Zhao a, Feng Zhu b, Yongjian Ma b, Xiaowei Li a, Hong Miao a, *, Yongning Wu a a
The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, 7 Panjiayuannanli, Beijing 100021, China b Jiangsu Province Center for Disease Control and Prevention, Nanjing 210009, China
a r t i c l e i n f o
a b s t r a c t
Article history: Received 25 March 2015 Received in revised form 11 September 2015 Accepted 14 November 2015 Available online 1 December 2015
The levels of acrylamide in 240 food composite samples from the 5th Chinese Total Diet Study (TDS) were measured using an LC-MS/MS method and the exposure estimates for the general population were evaluated. The samples were collected from 20 provinces in China, covering about two thirds of the Chinese population. Acrylamide was detected in 40.0% of composite samples with the concentrations ranged from 0.8 to 211.8 mg/kg. The average dietary intakes from the 5th Chinese TDS were 0.319 mg kg1 bw day1 and an increase with about 70% was observed from the 3rd Chinese TDS in 2000 to the 5th Chinese TDS between 2009 and 2012. The main food group contributors to acrylamide exposure were vegetables (35.2%), cereals (34.3%) and potatoes (15.7%). Based on the benchmark dose lower confidence limit at 10% risk (BMDL10) of 0.31 mg kg1 bw day1 for the induction of mammary tumors in rats and 0.18 mg kg1 bw day1 for Harderian gland tumors in mice, the margins of exposure (MOEs) were 973 and 565 for Chinese general population, respectively. These MOEs indicate a human health concern. © 2015 Elsevier Ltd. All rights reserved.
Keywords: Acrylamide Dietary exposure Risk assessment Total Diet Study China
1. Introduction Acrylamide is an industrial chemical commonly used for the production of polyacrylamides, which are wildly used in wastewater treatment, papermaking, gel electrophoresis, and cosmetics. Previous studies have demonstrated that acrylamide was carcinogenic to experimental animals and could induce tumors at multiple organ sites after the administration of acrylamide (Bull et al., 1984; Johnson et al., 1986). Acrylamide has been classified as probably carcinogenic to humans (Group 2A) by the International Agency for Research on Cancer (IARC, 1994). In addition, acrylamide has been shown to be neurotoxic in humans and reproductive toxic and genotoxic in laboratory animals (Friedman, 2003). In 2002, the Swedish National Food Administration and Stockholm University reported the presence of acrylamide with high levels in a variety of fried and oven-baked foods for the first time (SNFA, 2013). The finding was soon confirmed by other research groups and caused worldwide concern (Ahn et al., 2002; USFDA, 2002b; WHO, 2002). Efforts were subsequently carried out to understand the
* Corresponding author. E-mail address: [email protected] (H. Miao). http://dx.doi.org/10.1016/j.fct.2015.11.013 0278-6915/© 2015 Elsevier Ltd. All rights reserved.
mechanism of acrylamide formation in heat-treated foods. It has been shown that acrylamide is mainly formed via the Maillard reaction between reducing sugars and free amino acids, such as asparagines at high temperatures (Mottram et al., 2002; Stadler et al., 2002). Many studies have been conducted to determine levels of acrylamide in various foods and estimate the dietary intake of acrylamide for general population in some countries and regions (Konings et al., 2003; Mills et al., 2008; Powers et al., 2013; RufianHenares et al., 2007; Sirot et al., 2012). The FAO/WHO Joint Expert Committee of Food Additives (JECFA) recently evaluated data on acrylamide dietary intake of eight representative countries from all regions except Africa (JECFA, 2011). Results demonstrated no major changes in dietary exposures for the general population around the world had occurred since the last evaluation performed by the sixty-fourth meeting (JECFA, 2006), although the exposure for some population subgroups might significantly reduce. The mean dietary exposure was estimated to be 1 mg kg1 bw day1 while the exposure for consumers in the high (95the97.5th) percentile was 4 mg kg1 bw day1. Comparing these exposures to toxicological reference values, the margins of exposure for acrylamide indicate a human health concern. The Total Diet Study (TDS) is recommended by the World Health
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Organization as an effective tool to provide reliable estimates of general population to contaminants and help the risk manager in making public health decisions (WHO, 2005). In China, TDSs have been conducted five times. The first TDS was carried out in China in 1990 (Chen and Gao, 1993), the second in 1992, the third in 2000 (Zhao et al., 2004), the fourth in 2007 (Zhou et al., 2013), and the fifth between 2009 and 2012. The dietary intakes of various contaminants were estimated from Chinese TDSs, including persistent organochlorine pesticides, polychlorinated dibenzo-p-dioxins, dioxin-like dibenzofurans polychlorinated biphenyls, heavy metal elements, acrylamide, iodine among others (Li et al., 2007, 2006; Wu et al., 2012; Zhang et al., 2013; Zhao et al., 2004; Zhou et al., 2012, 2013). The dietary acrylamide exposures from the 3rd and 4th Chinese TDSs have been assessed (Zhou et al., 2013). In this study, 240 composite samples of 12 food groups from the 5th Chinese TDS, covering 20 provinces in China, were analyzed, and the dietary exposure of Chinese general population to acrylamide was estimated. In addition, time trends of dietary exposure to acrylamide from the 3rd Chinese TDS in 2000 to the 5th Chinese TDS now were compared and the potential health risk of acrylamide for the Chinese was discussed.
eggs and egg products (eggs), (6) aquatic foods and aquatic food products (aquatic foods), (7) milk and milk products (milk), (8) vegetables and vegetable products (vegetables), (9) fruits and fruit products (fruits), (10) sugars, (11) water and beverages, and (12) alcoholic beverages. The composite samples were prepared on the basis of food consumption data from each province. Finally, samples were homogenized and then frozen at 20 C until analysis. 2.3. Analytical methods
2. Materials and methods
Acrylamide analysis was performed according to the United States Food and Drug Administration (US FDA) methodology (USFDA, 2002a) with some modifications. In brief, samples were ultrasonically extracted by water, followed by a solid phase extraction clean-up using Oasis HLB (200 mg 6 cc, Waters, USA) and BondElut Accucat (200 mg 3 cc, Agilent, USA) cartridges. Acrylamide was detected by liquid chromatography (ACCELA, Thermo Fisher, USA) onan Atlantis T3 column (2.1 mm 150 mm, 3 mm; Waters, USA) coupled to a triple quadruple mass spectrometer (TSQ Quantum Access MAX, Thermo Fisher, USA), using the isotopic dilution technique (d3-acrylamide as the internal standards) for the quantitation. The limits of detection (LOD) for liquid samples and solid samples were 0.3 and 1.2 mg/kg, respectively.
2.1. Food consumption survey
2.4. Quality control
The strategy of 5th Chinese TDS was consistent with the previous TDSs in China, except that this study was expanded to 20 provinces, including the 12 provinces in the previous TDSs, which represents dietary patterns of various geographical regions of China and covering nearly two-thirds of the total Chinese population. The consumption data was collected by Chinese Center for Disease Control and Prevention (Chinese CDC) in 2009. The methodology of food consumption survey is described elsewhere (Wu et al., 2012; Zhou et al., 2012). Briefly, in each province, three survey sites (one urban and two rural) were selected to represent the local dietary pattern. The consumption data was obtained by a 3d household dietary survey and 24-h recalls. The average food consumption of a standard Chinese man (18e45 years old, 63 kg body weight) in 90 households (30 household per survey site) was then used as the standard food consumption pattern for the province.
The laboratory performance for the determination of acrylamide was validated by successfully participating in inter-comparison studies organized by Food Analysis Performance Assessment Scheme (FAPAS) of the Central Science Laboratory (York, UK) in 2005 and received a Z-score of 0.5. To ensure quality of analysis, procedural blanks and quality control (QC) samples were analyzed. A FAPAS QC material (T3037QC) and an in-house prepared reference material (potato crisps) were served as quality control in each analytical batch.
2.2. Food sampling and preparation
D¼
2.5. Dietary exposure estimates Concentrations of acrylamide in TDS samples were combined with food consumption data, and dietary exposure was calculated according to the following formula: n X i¼1
Details on sampling methodology of the TDS in China are published elsewhere (Li et al., 2007; Zhang et al., 2013; Zhou et al., 2012). Originally, the whole country was divided into four geographical regions, and each region comprised five provinces (See Fig. 1): North 1 comprised Heilongjiang (HLJ), Liaoning (LN), Hebei (HeB), Jilin (JL) and Beijing (BJ); North 2 comprised Henan (HeN), Shanxi (SX), Ningxia (NX), Qinghai (QH) and Inner Mongolia (IM); South 1 comprised Jiangxi (JX), Fujian (FJ), Shanghai (SH), Jiangsu (JS) and Zhejiang (ZJ); South 2 comprised Hubei (HuB), Sichuan (SC), Guangxi (GX), Hunan (HuN) and Guangdong (GD); the new added provinces based on the 12 provinces of the 4th Chinese TDS were highlighted by italic. The samples were purchased from local markets, grocery stores, and rural households in each of the 3 survey sites in each province, and then prepared according to local cooking methods, including frying, steaming, boiling, pan-frying, and other traditional Chinese cooking methods. All the food consumed was aggregated in 12 food categories, including (1) cereals and cereal products (cereals), (2) legumes, nuts, and their products (legumes and nuts), (3) potatoes and potato products (potatoes), (4) meat and meat products (meat), (5)
Ci Fi 1000 W
(1)
where D is the total daily exposure to acrylamide of a standard Chinese man (mg kg1 bw day1), Ci is the concentrations of acrylamide in a food composite sample (mg/kg), Fi is the consumption of a food group (g/day), W is the body weight of a standard Chinese man (63 kg), n is the total number of food groups consumed. 1000 is the conversion factor from grams to kilograms. For analytical results below the LOD, 1/2 LOD was used to produce estimates. 2.6. Risk assessment At the sixty-fourth meeting of JECFA, the Committee noted that the No Observed Adverse Effect Level (NOAEL) for acrylamide induced morphological changes in nerves was 0.2 mg kg1 bw day1. There were no new studies in laboratory animals in which neurotoxic effects were observed at a dose below 0.2 mg kg1 bw day1 in recent years (JECFA, 2011). Moreover, JECFA proposed two different BMDL10 (lower limit on the benchmark dose for a 10% response) for acrylamide: 0.31 mg kg1 bw day1 for the induction of mammary
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99
Fig. 1. Twenty provinces involved in the 5th Chinese Total Diet Study.
tumors in rats and 0.18 mg kg1 bw day1for Harderian gland tumors in mice (JECFA, 2011). Mean exposures were compared with NOAEL and BMDL10 by calculating the corresponding margins of exposure (MOEs) for risk characterization purposes.
three Chinese TDSs. The significance level was set at a ¼ 0.05. 3. Results and discussion 3.1. Acrylamide levels in the 5th Chinese TDS composite samples
2.7. Statistical analysis Among the 240 TDS composite samples, 40.0% were detected with acrylamide. The detailed results were summarized in Table 1. Acrylamide levels ranged from not detected (ND) to 211.8 mg/kg. The highest mean concentration of acrylamide was found in potatoes (34.8 mg/kg, range from ND to 211.8 mg/kg), followed by
All statistical analyses were performed using SPSS 17.0 software (SPSS Inc., Chicago, IL, USA). Non-parametric test (KruskaleWallis test) was used to study the differences of dietary exposure and levels of acrylamide between different regions and between the
Table 1 Levels of acrylamide in food composites from the 5th Chinese TDS (mg/kg). North 1 HLJ
LN
HeB
JL
BJ
HeN
SX
NX
QH
IM
JX
FJ
SH
JS
ZJ
HuB
SC
GX
HuN
GD
Cereals Legumes and nuts Potatoes Meat Eggs Aquatic foods Milk Vegetables Fruits Sugars Water and beverages Alcoholic beverages
36.4 5.4 ND ND ND 34.2 ND 17.9 ND ND ND ND
ND ND ND 42.9 ND ND ND 17.7 ND ND ND ND
11.8 ND ND ND ND ND ND 28.9 ND 26.3 ND ND
7.3 19.9 19.9 3.6 3.9 7.2 0.8 22.4 1.8 ND ND 1.7
ND ND ND ND 12.2 ND ND ND ND ND ND ND
12.1 16.8 18.0 ND ND ND ND 30.5 ND 12.4 ND ND
ND 22.5 14.7 ND ND ND ND 12.0 ND ND ND ND
ND ND 19.1 13.9 ND ND ND 34.0 ND ND ND ND
4.8 16.7 38.1 20.2 2.9 17.7 2.3 50.3 ND 3.6 ND 7.7
12.5 15.2 23.0 18.7 3.0 7.8 1.4 22.3 1.0 180.6 ND 2.1
ND 18.4 46.0 ND ND ND ND 20.5 ND ND ND ND
ND ND ND ND ND 20.8 ND ND ND 13.5 ND ND
ND 17.4 ND 16.6 ND ND ND ND ND 17.5 ND ND
ND 14.9 36.4 ND ND ND ND ND ND ND ND ND
ND 7.2 32.2 ND ND ND ND ND ND 42.1 ND ND
ND 16.1 211.8 ND ND ND ND 13.4 ND ND ND ND
ND 11.5 121.5 9.2 35.2 65.3 ND 13.3 ND 10.0 ND 8.1
ND 10.6 66.5 16.8 11.4 11.2 ND 20.0 ND 98.3 ND ND
ND 39.8 33.8 ND ND 38.3 ND ND ND ND ND ND
3.3 10.4 11.2 4.4 2.2 3.6 27.3 44.6 ND 4.8 ND 9.2
a
North 2
Results lower than LOD were assigned 1/2 LOD in calculations.
South 1
Meana
Food composites
South 2
4.8 12.3 34.8 7.6 3.9 10.6 1.7 17.6 0.3 20.8 0.2 1.6
0.109 0.018 0.050 0.015 0.002 0.007 0.001 0.112 0.000 0.001 0.002 0.000 0.319 0.023 0.005 0.004 0.007 0.001 0.003 0.016 0.181 0.000 0.000 0.003 0.000 0.243 0.011 0.027 0.017 0.001 0.000 0.030 0.000 0.006 0.000 0.000 0.003 0.000 0.095 0.010 0.007 0.017 0.040 0.004 0.008 0.000 0.188 0.000 0.001 0.003 0.000 0.278 0.011 0.022 0.290 0.025 0.009 0.017 0.000 0.128 0.000 0.000 0.001 0.002 0.505 0.017 0.022 0.221 0.001 0.000 0.000 0.000 0.130 0.000 0.000 0.001 0.000 0.392 0.016 0.011 0.019 0.001 0.000 0.001 0.000 0.004 0.000 0.005 0.002 0.000 0.061 0.011 0.048 0.040 0.002 0.000 0.001 0.000 0.005 0.000 0.000 0.002 0.000 0.109 0.008 0.027 0.000 0.036 0.000 0.001 0.000 0.005 0.000 0.002 0.002 0.000 0.082 0.014 0.001 0.001 0.002 0.000 0.064 0.000 0.004 0.000 0.001 0.002 0.000 0.090 0.013 0.013 0.034 0.001 0.000 0.000 0.000 0.091 0.000 0.000 0.001 0.000 0.153 0.270 0.019 0.097 0.041 0.003 0.001 0.002 0.085 0.001 0.004 0.006 0.001 0.530 0.149 0.002 0.084 0.029 0.001 0.001 0.002 0.404 0.000 0.000 0.001 0.001 0.675 0.013 0.001 0.051 0.025 0.000 0.000 0.000 0.203 0.000 0.000 0.001 0.000 0.296 0.011 0.040 0.031 0.001 0.000 0.000 0.000 0.074 0.000 0.000 0.001 0.000 0.158 0.401 0.016 0.026 0.000 0.000 0.000 0.000 0.166 0.000 0.000 0.003 0.000 0.613 0.012 0.002 0.001 0.002 0.014 0.000 0.000 0.006 0.000 0.000 0.003 0.000 0.040 0.221 0.085 0.066 0.007 0.005 0.003 0.000 0.199 0.002 0.000 0.003 0.000 0.590 0.262 0.002 0.001 0.000 0.000 0.000 0.000 0.163 0.000 0.001 0.002 0.000 0.432 0.017 0.003 0.001 0.088 0.001 0.000 0.000 0.087 0.000 0.000 0.001 0.000 0.198 0.697 0.008 0.001 0.001 0.001 0.015 0.000 0.111 0.000 0.000 0.000 0.000 0.833 Cereals Legumes and nuts Potatoes Meat Eggs Aquatic foods Milk Vegetables Fruits Sugars Water and beverages Alcoholic beverages Total
GD HuN GX SC HuB
South 2
ZJ JS SH FJ JX
South 1
IM QH NX HeN
SX North 2
LN
HeB
JL
BJ HLJ
The dietary exposures to acrylamide of the Chinese general population based on the data of the 5th Chinese TDS were presented in Table 2. The mean dietary exposure to acrylamide was estimated as 0.319 mg kg1 bw day1 for the Chinese general population. A significant difference of dietary exposure was found among four regions in China (p < 0.05). Among various provinces, the dietary intakes of acrylamide varied considerably from the minimum of 0.040 mg kg1 bw day1 in Beijing to the maximum of 0.833 mg kg1 bw day1 in Heilongjiang. The large difference arises from variations in contamination levels as well as food
North 1
3.2. Estimated dietary intake of acrylamide
Food composites
sugars (20.8 mg/kg, range from ND to 180.6 mg/kg), vegetables (17.6 mg/kg, range from ND to 50.3 mg/kg), legumes and nuts (12.3 mg/kg, range from ND to 39.8 mg/kg), aquatic foods (10.6 mg/ kg, range from ND to 65.3 mg/kg), meats (7.6 mg/kg, range from ND to 42.9 mg/kg) and cereals (4.8 mg/kg, range from ND to 36.4 mg/kg), eggs (3.9 mg/kg, range from ND to 35.2 mg/kg). Milk (1.7 mg/kg, range from ND to 27.3 mg/kg), alcoholic beverages (1.6 mg/kg, range from ND to 9.2 mg/kg) and fruits (0.3 mg/kg, range from ND to 1.8 mg/kg) presented particularly low mean concentrations. Acrylamide was not detected in water and beverages. The highest concentration of acrylamide was found in the potato sample from Hubei province (211.8 mg/kg), followed by the sugar sample from Inner Mongolia (180.6 mg/kg) and the potato sample from Sichuan province (121.5 mg/kg). Starchy foods such as potatoes cooked at high temperatures (above 120 C) upon frying, roasting, and baking are liable to produce large amounts of acrylamide. The high acrylamide levels found in sugars were proved to be mainly derived from brown sugars by trace ability analysis. High acrylamide content in brown sugars has been reported in previous studies (Zhou et al., 2013). The levels of acrylamide measured varied considerably in the samples of the same food category between different provinces. Previous studies (Ahn et al., 2002; Becalski et al., 2003; Mottram et al., 2002) showed that several factors, including heating temperature, cooking methods and amounts of carbohydrates and amino acids, might contribute to the formation of acrylamide, which cause a large variation in the levels of acrylamide. Compared with acrylamide levels from the general European or international studies (EFSA, 2012; JECFA, 2011), the mean concentrations in Chinese TDS samples were much lower, particularly in potatoes, cereals, sugars and fruits. For French fries and potato crisps, EFSA reported the mean acrylamide concentrations in the recent year (2010) were 338 mg/kg and 675 mg/kg, respectively. The mean acrylamide concentration in potato and potato products was 532 mg/kg in the 72nd report of JECFA. However, the mean acrylamide concentration of potatoes from the 5th Chinese TDS was 34.8 mg/kg, much lower than the European level and the international level. Similarly, the mean acrylamide level of cereals sample from the 5th Chinese TDS (4.8 mg/kg) was also far lower than the international level (273 mg/kg). Although high acrylamide levels were found in brown sugars, the mean level of sugars from the 5th Chinese TDS was not high because of the low proportion of brown sugars in the composite samples, much lower than the mean concentration (332 mg/kg) of sugars reported by JECFA. Only very little acrylamide was detected in fruits (0.3 mg/kg) in the 5th Chinese TDS, while high mean acrylamide level (110 mg/kg) was found in fruits according to international data. On the 72th JECFA meeting, the global mean acrylamide levels of meats and offals (42 mg/kg), eggs (18 mg/kg), fish and seafood (64 mg/kg), vegetables (52 mg/kg), and alcoholic beverages (17 mg/kg) were reported, obviously higher than the Chinese level.
Mean
J. Gao et al. / Food and Chemical Toxicology 87 (2016) 97e102
Table 2 Estimated dietary intake of acrylamide from the 5th Chinese TDS (mg kg1 bw day1).
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consumption values in different provinces. Different dietetic habits and cooking styles among provinces could be mainly responsible for the difference. Fig. 2 showed the contributions of different food categories to the overall estimated acrylamide exposure for the Chinese population in the 5th Chinese TDS. Vegetables and cereals accounted for 35.2% and 34.3% of the acrylamide intake, respectively, thus being with no doubt the main contributors. For most provinces in China, high consumption of vegetables and cereals resulted in the most important food sources of acrylamide. However, vegetables and cereals contribution percentages greatly varied among regions. Vegetables made the largest contribution and were responsible for over half of dietary acrylamide exposure in Ningxia, Qinghai, Jiangxi, Guangxi and Guangdong, whereas over half of dietary acrylamide intake was derived from the consumption of cereals in Heilongjiang, Hebei, Henan and Inner Mongolia. Furthermore, potatoes were also considerable contributions (15.7%). Generally, other food items contributed less than 10% to the total dietary exposure. The contribution pattern of dietary acrylamide exposure for Chinese population differed from other international studies. In the recent EFSA assessment report (EFSA, 2011), the four major contributors of acrylamide exposure for adults were fried potatoes (12.9e64.6%), unspecified bread (0.2e59.3%), soft bread (0.0e21.6%) and biscuit (0.0e12.1%). Besides, JECFA reported potato chips (10e60%), potato crisps (10e22%), bread and rolls/toast (13e34%) and pastry and sweet biscuits (10e15%) as the main contributors of dietary acrylamide intake in most countries (JECFA, 2011). The difference could be explained by different dietetic habits between China and most western countries. Chinese dietary pattern is dominated by vegetables and cereals, and is inconsistent with those of the vast majority of western countries. The result of the dietary exposure assessment in this study was compared with the 3rd and the 4th Chinese TDS (Zhou et al., 2013). The mean dietary acrylamide intakes from the 3rd, the 4th and the 5th Chinese TDS were 0.188, 0.286, and 0.319 mg kg1 bw day1, respectively, and an increase with about 70% was observed from 2000 to now. The dietary intakes of acrylamide of each food category from the three Chinese TDSs were compared in Table 3. Acrylamide levels and food consumption vary in the three TDSs, both of which could lead to the differences in dietary exposure of acrylamide. Based on statistical analysis, no significant differences were found in dietary exposure and levels of acrylamide between the 4th and 5th TDSs. Because the dietary exposure of each region (not each province) was evaluated in the 3rd TDS, we cannot compare the 3rd TDS with the 4th and 5th TDSs using statistical analysis. For several main contributors, such as cereals, legumes and nuts, and potatoes, a notable increase was observed from the
The 3rd TDS
The 4th TDS
The 5th TDS
Cereals Legumes and nuts Potatoes Meat Eggs Aquatic foods Milk Vegetables Fruits Sugars Water and beverages Alcoholic beverages Total
0.049 0.013 0.023 0.001 0.000 0.001 0.000 0.101 0.001 0.000 0.000 0.002 0.188
0.076 0.016 0.023 0.019 0.000 0.006 0.000 0.136 0.001 0.002 0.001 0.000 0.286
0.109 0.018 0.050 0.015 0.002 0.007 0.001 0.112 0.000 0.001 0.002 0.000 0.319
3rd TDS to the 5th TDS. However, the dietary exposure to acrylamide from vegetables first increase and then decrease. Furthermore, the acrylamide intakes of individual provinces were compared between the 4th and 5th Chinese TDS (Fig. 3). Interestingly, a geographic change was observed. In the three provinces of South 1, there was a notable decline from the 4th and 5th Chinese TDS, whereas a considerable increase was observed in the three provinces of South 2. Dietary exposure assessments of acrylamide have been done for general population in many countries in recent years. The mean dietary acrylamide exposures for the general population around the world were also reported to be 1 mg kg1 bw day1 by JECFA (JECFA, 2011). Thus, dietary exposure of Chinese population may be at a lower level than other countries. The average dietary intake from the 5th Chinese TDS was lower than those from France (0.43 mg kg1 bw day1) (Sirot et al., 2012), the United Kingdom (0.61 mg kg1 bw day1) (Mills et al., 2008), Ireland (0.59 mg kg1 bw day1) (Mills et al., 2008), the Netherlands (0.48 mg kg1 bw day1) (Konings et al., 2003), Sweden (0.49 mg kg1 bw day1) (Svensson et al., 2003) and Poland (0.33 mg kg1 bw day1) (Mojska et al., 2010), except for Spain (0.2 mg kg1 bw day1) (Rufian-Henares et al., 2007). 3.3. Risk assessment of dietary exposure to acrylamide The overall Chinese exposure estimates yielded MOEs (based on the NOAEL of 0.2 mg kg1 bw day1) that was 628 for morphological nerve changes. For Chinese general population, the MOEs calculated based on the BMDL10 of 0.31 mg kg1 bw day1 for the induction of mammary tumors in female rats and the BMDL10 of 0.18 mg kg1 bw day1 for Harderian gland tumors in male mice were 973 and 565. These MOE values obtained in this study were
34.3%
Eggs AquaƟc foods Milk
0.3%
Vegetables
2.3%
Fruits
4.8%
Sugars 5.7%
Water and beverage Alcoholic beverage
Fig. 2. Contribution (% of Daily Intake) of the different food groups to dietary acrylamide intakes for Chinese general population.
0.9 Dietary expsoure to acrylamide (μg·kg-1 bw·day-1)
Potatoes Meat
15.7%
Food composites
Legumes and nuts 0.1%
35.2%
0.7%
Table 3 Comparison of estimated daily dietary exposure to acrylamide from different food groups from the 3rd, 4th and 5th Chinese TDS (mg kg1 bw day1).
Cereals
0.6% 0.2% 0.1%
101
0.8 0.7 0.6 0.5 0.4
The 4th TDS
0.3
The 5th TDS
0.2 0.1 0 HLJ
LN HeB SX HeN NX
SH
FJ
JX HuB SC
GX
Provinces
Fig. 3. Comparative daily intakes of acrylamide from the 4th and 5th TDS in various provinces in China.
102
J. Gao et al. / Food and Chemical Toxicology 87 (2016) 97e102
higher than those values (310 and 180) reported by JECFA. Nevertheless, compared with MOE values from the 3rd Chinese TDS (1653 and 960) and the 4th Chinese TDS (1069 and 621), a decrease was observed in the past decade. The assessment results indicated a health concern and a need to reduce acrylamide exposure in China, especially several provinces with low MOE values, such as Heilongjiang, Henan, Jilin, Inner Mongolia, Qinghai and Sichuan. It is therefore advisable to reduce dietary exposure to acrylamide by changing food processing methods and make reasonable selection of foodstuffs in daily diet for Chinese population. People should eat a balanced and varied diet, which includes plenty of fruit and vegetables, and should limit their consumption of fried foods, particularly potato chips and fried potatoes. People are advised to cook foods by steaming and boiling, not to cook them for too long or at too high a temperature, in order to reduce the formation of acrylamide (FEHD, 2013; WHO, 2002). 4. Conclusion The mean dietary exposure of acrylamide for the Chinese population is estimated to be 0.319 mg kg1 bw day1, which was relatively lower than that of the international level assessed by JECFA. However, the MOE values obtained still indicated a potential health risk. The last three Chinese TDS showed a notable upward trend in the aspect of acrylamide exposure. This study highlighted the need to continue to monitor dietary acrylamide exposure in China. Conflicts of interest The authors declare that there are no conflicts of interest. Acknowledgments We thank 20 provincial Centers for Disease Control and Prevention for sampling and dietary sample preparation. This work was supported by the National Science and Technology Support Program of China (Grant No. 2012BAK01B01). Appendix A. Supplementary data Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.fct.2015.11.013. References Ahn, J.S., Castle, L., Clarke, D.B., Lloyd, A.S., Philo, M.R., Speck, D.R., 2002. Verification of the findings of acrylamide in heated foods. Food Addit. Contam. 19, 1116e1124. Becalski, A., Lau, B.P.Y., Lewis, D., Seaman, S.W., 2003. Acrylamide in foods: occurrence, sources, and modeling. J. Agric. Food Chem. 51, 802e808. Bull, R.J., Robinson, M., Laurie, R.D., Stoner, G.D., Greisiger, E., Meier, J.R., Stober, J., 1984. Carcinogenic effects of acrylamide in sencar and A/J mice. Cancer Res. 44, 107e111. Chen, J., Gao, J., 1993. The Chinese total diet study in 1990. Part I. Chemical contaminants. J. AOAC Int. 76, 1193e1205. European Food Safety Authority (EFSA), 2011. Results on acrylamide levels in food from monitoring years 2007 to 2009 and exposure assessment. EFSA J. 9, 2133. European Food Safety Authority (EFSA), 2012. Update on acrylamide levels in food from monitoring years 2007 to 2010. EFSA J. 10, 2938. Food and Environmental Hygiene Department (FEHD), The Government of the Hong Kong Special Administrative Region, 2013. The First Hong Kong Total Diet Study: Acrylamide. http://www.cfs.gov.hk/english/programme/programme_
firm/files/The_first_HKTDS_acrylamide_final_e.pdf. Friedman, M., 2003. Chemistry, biochemistry, and safety of acrylamide. A review. J. Agric. Food Chem. 51, 4504e4526. International Agency for Research on Cancer (IARC), 1994. Lyon, France. Monographs on the Evaluation of Carcinogenic Risks to Humans: Some Industrial Chemicals, 60, p. 389. Johnson, K.A., Gorzinski, S.J., Bodner, K.M., Campbell, R.A., Wolf, C.H., Friedman, M.A., Mast, R.W., 1986. Chronic toxicity and oncogenicity study on acrylamide incorporated in the drinking water of Fischer 344 rats. Toxicol. Appl. Pharmacol. 85, 154e168. Konings, E.J.M., Baars, A.J., van Klaveren, J.D., Spanjer, M.C., Rensen, P.M., Hiemstra, M., van Kooij, J.A., Peterse, P.W.J., 2003. Acrylamide exposure from foods of the Dutch population and an assessment of the consequent risks. Food Chem. Toxicol. 41, 1569e1579. Li, X., Gao, J., Chen, J., 2006. Chinese total diet study in 2000-the dietary mercuric intakes. Wei Sheng Yan Jiu 35, 323e325. Li, J., Wu, Y., Zhang, L., Zhao, Y., 2007. Dietary intake of polychlorinated dioxins, furans and dioxin-like polychlorinated biphenyls from foods of animal origin in China. Food Addit. Contam. 24, 186e193. Mills, C., Tlustos, C., Evans, R., Matthews, W., 2008. Dietary acrylamide exposure estimates for the United Kingdom and Ireland: comparison between semiprobabilistic and probabilistic exposure models. J. Agric. Food Chem. 56, 6039e6045. ska, I., Szponar, L., Ołtarzewskiet, M., 2010. Estimation of the Mojska, H., Gielecin dietary acrylamide exposure of the Polish population. Food Chem. Toxicol. 48, 2090e2096. Mottram, D.S., Wedzicha, B.L., Dodson, A.T., 2002. Acrylamide is formed in the Maillard reaction. Nature 419, 448e449. Powers, S.J., Mottram, D.S., Curtisc, A., Halford, N.G., 2013. Acrylamide concentrations in potato crisps in Europe from 2002 to 2011. Food Addit. Contam. A 30, 1493e1500. Rufian-Henares, J.A., Arribas-Lorenzo, G.A., Moralesa, F.J., 2007. Acrylamide content of selected Spanish foods: survey of biscuits and bread derivatives. Food Addit. Contam. 24, 343e350. Sirot, V., Hommet, F., Tard, A., Leblanc, J.C., 2012. Dietary acrylamide exposure of the French population: results of the second French Total Diet Study. Food Chem. Toxicol. 50, 889e894. Swedish National Food Administration (SNFA), 2013. Acrylamide in Summary. http://www.slv.se/en-gb/Group1/Food-Safety/Acrylamide/. Stadler, R.H., Blank, I., Varga, N., Robert, F., Hau, J., Guy, P.A., Robert, M.C., Riedecker, S., 2002. Acrylamide from Maillard reaction products. Nature 419, 449e450. n, J., Svensson, K., Abramsson, L., Becker, W., Glynn, A., Hellen€ as, K.E., Lind, Y., Rose 2003. Dietary intake of acrylamide in Sweden. Food Chem. Toxicol. 41, 1581e1586. The Joint FAO/WHO Expert Committee on Food Additives (JECFA), 2006. Evaluation of Certain Contaminants in Food: Sixty-fourth Report of the Joint FAO/WHO Expert Committee on Food Additives. World Health Organization, Geneva, Switzerland. The Joint FAO/WHO Expert Committee on Food Additives (JECFA), 2011. Evaluation of Certain Contaminants in Food: Seventy-second Report of the Joint FAO/WHO Expert Committee on Food Additives. World Health Organization, Geneva, Switzerland. U.S. Food and Drug Administration (USFDA), 2002a. Detection and Quantitation of Acrylamide in Foods. http://www.fda.gov/Food/FoodborneIllnessContaminants/ ChemicalContaminants/ucm053537.htm. U.S. Food and Drug Administration (USFDA), 2002b. Survey Data on Acrylamide in Food: Individual Food Products. http://www.fda.gov/food/ foodborneillnesscontaminants/%20chemicalcontaminants/ucm053549.htm. WHO, 2002. Health Implications of Acrylamide in Food. Report of a Joint FAO/WHO Consultation. World Health Organization, Geneva, Switzerland. WHO, 2005. Total Diet Studies: a Recipe for Safer Food. http://www.who.int/ foodsafety/chem/TDS_recipe_2005_en.pdf. Wu, Y., Li, X., Chang, S., Liu, L., Zou, S., Hipgrave, D.B., 2012. Variable iodine intake persists in the context of universal salt iodization in China. J. Nutr. 142, 1728e1734. Zhang, L., Li, J., Liu, X., Zhao, Y., Li, X., Wen, S., Wu, Y., 2013. Dietary intake of PCDD/Fs and dioxin-like PCBs from the Chinese total diet study in 2007. Chemosphere 90, 1625e1630. Zhao, Y., Li, J., Feng, J., Zhao, J., Wu, Y., 2004. Contamination source identification study of organochlorines pesticides in 2000 Chinese total diet study. Wei Sheng Yan Jiu 33, 475e477. Zhou, P., Zhao, Y., Li, J., Wu, G., Zhang, L., Liu, Q., Fan, S., Yang, X., Li, X., Wu, Y., 2012. Dietary exposure to persistent organochlorine pesticides in 2007 Chinese total diet study. Environ. Int. 42, 152e159. Zhou, P., Zhao, Y., Liu, H., Ma, Y., Li, X., Yang, X., Wu, Y., 2013. Dietary exposure of the Chinese population to acrylamide. Biomed. Environ. Sci. 26, 421e429.
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Dietary exposure of acrylamide from the fifth Chinese Total Diet Study Jie Gao a, Yunfeng Zhao a, Feng Zhu b, Yongjian Ma b, Xiaowei Li a, Hong Miao a, *, Yongning Wu a a
The Key Laboratory of Food Safety Risk Assessment, Ministry of Health, and China National Center for Food Safety Risk Assessment, 7 Panjiayuannanli, Beijing 100021, China b Jiangsu Province Center for Disease Control and Prevention, Nanjing 210009, China
a r t i c l e i n f o
a b s t r a c t
Article history: Received 25 March 2015 Received in revised form 11 September 2015 Accepted 14 November 2015 Available online 1 December 2015
The levels of acrylamide in 240 food composite samples from the 5th Chinese Total Diet Study (TDS) were measured using an LC-MS/MS method and the exposure estimates for the general population were evaluated. The samples were collected from 20 provinces in China, covering about two thirds of the Chinese population. Acrylamide was detected in 40.0% of composite samples with the concentrations ranged from 0.8 to 211.8 mg/kg. The average dietary intakes from the 5th Chinese TDS were 0.319 mg kg1 bw day1 and an increase with about 70% was observed from the 3rd Chinese TDS in 2000 to the 5th Chinese TDS between 2009 and 2012. The main food group contributors to acrylamide exposure were vegetables (35.2%), cereals (34.3%) and potatoes (15.7%). Based on the benchmark dose lower confidence limit at 10% risk (BMDL10) of 0.31 mg kg1 bw day1 for the induction of mammary tumors in rats and 0.18 mg kg1 bw day1 for Harderian gland tumors in mice, the margins of exposure (MOEs) were 973 and 565 for Chinese general population, respectively. These MOEs indicate a human health concern. © 2015 Elsevier Ltd. All rights reserved.
Keywords: Acrylamide Dietary exposure Risk assessment Total Diet Study China
1. Introduction Acrylamide is an industrial chemical commonly used for the production of polyacrylamides, which are wildly used in wastewater treatment, papermaking, gel electrophoresis, and cosmetics. Previous studies have demonstrated that acrylamide was carcinogenic to experimental animals and could induce tumors at multiple organ sites after the administration of acrylamide (Bull et al., 1984; Johnson et al., 1986). Acrylamide has been classified as probably carcinogenic to humans (Group 2A) by the International Agency for Research on Cancer (IARC, 1994). In addition, acrylamide has been shown to be neurotoxic in humans and reproductive toxic and genotoxic in laboratory animals (Friedman, 2003). In 2002, the Swedish National Food Administration and Stockholm University reported the presence of acrylamide with high levels in a variety of fried and oven-baked foods for the first time (SNFA, 2013). The finding was soon confirmed by other research groups and caused worldwide concern (Ahn et al., 2002; USFDA, 2002b; WHO, 2002). Efforts were subsequently carried out to understand the
* Corresponding author. E-mail address: [email protected] (H. Miao). http://dx.doi.org/10.1016/j.fct.2015.11.013 0278-6915/© 2015 Elsevier Ltd. All rights reserved.
mechanism of acrylamide formation in heat-treated foods. It has been shown that acrylamide is mainly formed via the Maillard reaction between reducing sugars and free amino acids, such as asparagines at high temperatures (Mottram et al., 2002; Stadler et al., 2002). Many studies have been conducted to determine levels of acrylamide in various foods and estimate the dietary intake of acrylamide for general population in some countries and regions (Konings et al., 2003; Mills et al., 2008; Powers et al., 2013; RufianHenares et al., 2007; Sirot et al., 2012). The FAO/WHO Joint Expert Committee of Food Additives (JECFA) recently evaluated data on acrylamide dietary intake of eight representative countries from all regions except Africa (JECFA, 2011). Results demonstrated no major changes in dietary exposures for the general population around the world had occurred since the last evaluation performed by the sixty-fourth meeting (JECFA, 2006), although the exposure for some population subgroups might significantly reduce. The mean dietary exposure was estimated to be 1 mg kg1 bw day1 while the exposure for consumers in the high (95the97.5th) percentile was 4 mg kg1 bw day1. Comparing these exposures to toxicological reference values, the margins of exposure for acrylamide indicate a human health concern. The Total Diet Study (TDS) is recommended by the World Health
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Organization as an effective tool to provide reliable estimates of general population to contaminants and help the risk manager in making public health decisions (WHO, 2005). In China, TDSs have been conducted five times. The first TDS was carried out in China in 1990 (Chen and Gao, 1993), the second in 1992, the third in 2000 (Zhao et al., 2004), the fourth in 2007 (Zhou et al., 2013), and the fifth between 2009 and 2012. The dietary intakes of various contaminants were estimated from Chinese TDSs, including persistent organochlorine pesticides, polychlorinated dibenzo-p-dioxins, dioxin-like dibenzofurans polychlorinated biphenyls, heavy metal elements, acrylamide, iodine among others (Li et al., 2007, 2006; Wu et al., 2012; Zhang et al., 2013; Zhao et al., 2004; Zhou et al., 2012, 2013). The dietary acrylamide exposures from the 3rd and 4th Chinese TDSs have been assessed (Zhou et al., 2013). In this study, 240 composite samples of 12 food groups from the 5th Chinese TDS, covering 20 provinces in China, were analyzed, and the dietary exposure of Chinese general population to acrylamide was estimated. In addition, time trends of dietary exposure to acrylamide from the 3rd Chinese TDS in 2000 to the 5th Chinese TDS now were compared and the potential health risk of acrylamide for the Chinese was discussed.
eggs and egg products (eggs), (6) aquatic foods and aquatic food products (aquatic foods), (7) milk and milk products (milk), (8) vegetables and vegetable products (vegetables), (9) fruits and fruit products (fruits), (10) sugars, (11) water and beverages, and (12) alcoholic beverages. The composite samples were prepared on the basis of food consumption data from each province. Finally, samples were homogenized and then frozen at 20 C until analysis. 2.3. Analytical methods
2. Materials and methods
Acrylamide analysis was performed according to the United States Food and Drug Administration (US FDA) methodology (USFDA, 2002a) with some modifications. In brief, samples were ultrasonically extracted by water, followed by a solid phase extraction clean-up using Oasis HLB (200 mg 6 cc, Waters, USA) and BondElut Accucat (200 mg 3 cc, Agilent, USA) cartridges. Acrylamide was detected by liquid chromatography (ACCELA, Thermo Fisher, USA) onan Atlantis T3 column (2.1 mm 150 mm, 3 mm; Waters, USA) coupled to a triple quadruple mass spectrometer (TSQ Quantum Access MAX, Thermo Fisher, USA), using the isotopic dilution technique (d3-acrylamide as the internal standards) for the quantitation. The limits of detection (LOD) for liquid samples and solid samples were 0.3 and 1.2 mg/kg, respectively.
2.1. Food consumption survey
2.4. Quality control
The strategy of 5th Chinese TDS was consistent with the previous TDSs in China, except that this study was expanded to 20 provinces, including the 12 provinces in the previous TDSs, which represents dietary patterns of various geographical regions of China and covering nearly two-thirds of the total Chinese population. The consumption data was collected by Chinese Center for Disease Control and Prevention (Chinese CDC) in 2009. The methodology of food consumption survey is described elsewhere (Wu et al., 2012; Zhou et al., 2012). Briefly, in each province, three survey sites (one urban and two rural) were selected to represent the local dietary pattern. The consumption data was obtained by a 3d household dietary survey and 24-h recalls. The average food consumption of a standard Chinese man (18e45 years old, 63 kg body weight) in 90 households (30 household per survey site) was then used as the standard food consumption pattern for the province.
The laboratory performance for the determination of acrylamide was validated by successfully participating in inter-comparison studies organized by Food Analysis Performance Assessment Scheme (FAPAS) of the Central Science Laboratory (York, UK) in 2005 and received a Z-score of 0.5. To ensure quality of analysis, procedural blanks and quality control (QC) samples were analyzed. A FAPAS QC material (T3037QC) and an in-house prepared reference material (potato crisps) were served as quality control in each analytical batch.
2.2. Food sampling and preparation
D¼
2.5. Dietary exposure estimates Concentrations of acrylamide in TDS samples were combined with food consumption data, and dietary exposure was calculated according to the following formula: n X i¼1
Details on sampling methodology of the TDS in China are published elsewhere (Li et al., 2007; Zhang et al., 2013; Zhou et al., 2012). Originally, the whole country was divided into four geographical regions, and each region comprised five provinces (See Fig. 1): North 1 comprised Heilongjiang (HLJ), Liaoning (LN), Hebei (HeB), Jilin (JL) and Beijing (BJ); North 2 comprised Henan (HeN), Shanxi (SX), Ningxia (NX), Qinghai (QH) and Inner Mongolia (IM); South 1 comprised Jiangxi (JX), Fujian (FJ), Shanghai (SH), Jiangsu (JS) and Zhejiang (ZJ); South 2 comprised Hubei (HuB), Sichuan (SC), Guangxi (GX), Hunan (HuN) and Guangdong (GD); the new added provinces based on the 12 provinces of the 4th Chinese TDS were highlighted by italic. The samples were purchased from local markets, grocery stores, and rural households in each of the 3 survey sites in each province, and then prepared according to local cooking methods, including frying, steaming, boiling, pan-frying, and other traditional Chinese cooking methods. All the food consumed was aggregated in 12 food categories, including (1) cereals and cereal products (cereals), (2) legumes, nuts, and their products (legumes and nuts), (3) potatoes and potato products (potatoes), (4) meat and meat products (meat), (5)
Ci Fi 1000 W
(1)
where D is the total daily exposure to acrylamide of a standard Chinese man (mg kg1 bw day1), Ci is the concentrations of acrylamide in a food composite sample (mg/kg), Fi is the consumption of a food group (g/day), W is the body weight of a standard Chinese man (63 kg), n is the total number of food groups consumed. 1000 is the conversion factor from grams to kilograms. For analytical results below the LOD, 1/2 LOD was used to produce estimates. 2.6. Risk assessment At the sixty-fourth meeting of JECFA, the Committee noted that the No Observed Adverse Effect Level (NOAEL) for acrylamide induced morphological changes in nerves was 0.2 mg kg1 bw day1. There were no new studies in laboratory animals in which neurotoxic effects were observed at a dose below 0.2 mg kg1 bw day1 in recent years (JECFA, 2011). Moreover, JECFA proposed two different BMDL10 (lower limit on the benchmark dose for a 10% response) for acrylamide: 0.31 mg kg1 bw day1 for the induction of mammary
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99
Fig. 1. Twenty provinces involved in the 5th Chinese Total Diet Study.
tumors in rats and 0.18 mg kg1 bw day1for Harderian gland tumors in mice (JECFA, 2011). Mean exposures were compared with NOAEL and BMDL10 by calculating the corresponding margins of exposure (MOEs) for risk characterization purposes.
three Chinese TDSs. The significance level was set at a ¼ 0.05. 3. Results and discussion 3.1. Acrylamide levels in the 5th Chinese TDS composite samples
2.7. Statistical analysis Among the 240 TDS composite samples, 40.0% were detected with acrylamide. The detailed results were summarized in Table 1. Acrylamide levels ranged from not detected (ND) to 211.8 mg/kg. The highest mean concentration of acrylamide was found in potatoes (34.8 mg/kg, range from ND to 211.8 mg/kg), followed by
All statistical analyses were performed using SPSS 17.0 software (SPSS Inc., Chicago, IL, USA). Non-parametric test (KruskaleWallis test) was used to study the differences of dietary exposure and levels of acrylamide between different regions and between the
Table 1 Levels of acrylamide in food composites from the 5th Chinese TDS (mg/kg). North 1 HLJ
LN
HeB
JL
BJ
HeN
SX
NX
QH
IM
JX
FJ
SH
JS
ZJ
HuB
SC
GX
HuN
GD
Cereals Legumes and nuts Potatoes Meat Eggs Aquatic foods Milk Vegetables Fruits Sugars Water and beverages Alcoholic beverages
36.4 5.4 ND ND ND 34.2 ND 17.9 ND ND ND ND
ND ND ND 42.9 ND ND ND 17.7 ND ND ND ND
11.8 ND ND ND ND ND ND 28.9 ND 26.3 ND ND
7.3 19.9 19.9 3.6 3.9 7.2 0.8 22.4 1.8 ND ND 1.7
ND ND ND ND 12.2 ND ND ND ND ND ND ND
12.1 16.8 18.0 ND ND ND ND 30.5 ND 12.4 ND ND
ND 22.5 14.7 ND ND ND ND 12.0 ND ND ND ND
ND ND 19.1 13.9 ND ND ND 34.0 ND ND ND ND
4.8 16.7 38.1 20.2 2.9 17.7 2.3 50.3 ND 3.6 ND 7.7
12.5 15.2 23.0 18.7 3.0 7.8 1.4 22.3 1.0 180.6 ND 2.1
ND 18.4 46.0 ND ND ND ND 20.5 ND ND ND ND
ND ND ND ND ND 20.8 ND ND ND 13.5 ND ND
ND 17.4 ND 16.6 ND ND ND ND ND 17.5 ND ND
ND 14.9 36.4 ND ND ND ND ND ND ND ND ND
ND 7.2 32.2 ND ND ND ND ND ND 42.1 ND ND
ND 16.1 211.8 ND ND ND ND 13.4 ND ND ND ND
ND 11.5 121.5 9.2 35.2 65.3 ND 13.3 ND 10.0 ND 8.1
ND 10.6 66.5 16.8 11.4 11.2 ND 20.0 ND 98.3 ND ND
ND 39.8 33.8 ND ND 38.3 ND ND ND ND ND ND
3.3 10.4 11.2 4.4 2.2 3.6 27.3 44.6 ND 4.8 ND 9.2
a
North 2
Results lower than LOD were assigned 1/2 LOD in calculations.
South 1
Meana
Food composites
South 2
4.8 12.3 34.8 7.6 3.9 10.6 1.7 17.6 0.3 20.8 0.2 1.6
0.109 0.018 0.050 0.015 0.002 0.007 0.001 0.112 0.000 0.001 0.002 0.000 0.319 0.023 0.005 0.004 0.007 0.001 0.003 0.016 0.181 0.000 0.000 0.003 0.000 0.243 0.011 0.027 0.017 0.001 0.000 0.030 0.000 0.006 0.000 0.000 0.003 0.000 0.095 0.010 0.007 0.017 0.040 0.004 0.008 0.000 0.188 0.000 0.001 0.003 0.000 0.278 0.011 0.022 0.290 0.025 0.009 0.017 0.000 0.128 0.000 0.000 0.001 0.002 0.505 0.017 0.022 0.221 0.001 0.000 0.000 0.000 0.130 0.000 0.000 0.001 0.000 0.392 0.016 0.011 0.019 0.001 0.000 0.001 0.000 0.004 0.000 0.005 0.002 0.000 0.061 0.011 0.048 0.040 0.002 0.000 0.001 0.000 0.005 0.000 0.000 0.002 0.000 0.109 0.008 0.027 0.000 0.036 0.000 0.001 0.000 0.005 0.000 0.002 0.002 0.000 0.082 0.014 0.001 0.001 0.002 0.000 0.064 0.000 0.004 0.000 0.001 0.002 0.000 0.090 0.013 0.013 0.034 0.001 0.000 0.000 0.000 0.091 0.000 0.000 0.001 0.000 0.153 0.270 0.019 0.097 0.041 0.003 0.001 0.002 0.085 0.001 0.004 0.006 0.001 0.530 0.149 0.002 0.084 0.029 0.001 0.001 0.002 0.404 0.000 0.000 0.001 0.001 0.675 0.013 0.001 0.051 0.025 0.000 0.000 0.000 0.203 0.000 0.000 0.001 0.000 0.296 0.011 0.040 0.031 0.001 0.000 0.000 0.000 0.074 0.000 0.000 0.001 0.000 0.158 0.401 0.016 0.026 0.000 0.000 0.000 0.000 0.166 0.000 0.000 0.003 0.000 0.613 0.012 0.002 0.001 0.002 0.014 0.000 0.000 0.006 0.000 0.000 0.003 0.000 0.040 0.221 0.085 0.066 0.007 0.005 0.003 0.000 0.199 0.002 0.000 0.003 0.000 0.590 0.262 0.002 0.001 0.000 0.000 0.000 0.000 0.163 0.000 0.001 0.002 0.000 0.432 0.017 0.003 0.001 0.088 0.001 0.000 0.000 0.087 0.000 0.000 0.001 0.000 0.198 0.697 0.008 0.001 0.001 0.001 0.015 0.000 0.111 0.000 0.000 0.000 0.000 0.833 Cereals Legumes and nuts Potatoes Meat Eggs Aquatic foods Milk Vegetables Fruits Sugars Water and beverages Alcoholic beverages Total
GD HuN GX SC HuB
South 2
ZJ JS SH FJ JX
South 1
IM QH NX HeN
SX North 2
LN
HeB
JL
BJ HLJ
The dietary exposures to acrylamide of the Chinese general population based on the data of the 5th Chinese TDS were presented in Table 2. The mean dietary exposure to acrylamide was estimated as 0.319 mg kg1 bw day1 for the Chinese general population. A significant difference of dietary exposure was found among four regions in China (p < 0.05). Among various provinces, the dietary intakes of acrylamide varied considerably from the minimum of 0.040 mg kg1 bw day1 in Beijing to the maximum of 0.833 mg kg1 bw day1 in Heilongjiang. The large difference arises from variations in contamination levels as well as food
North 1
3.2. Estimated dietary intake of acrylamide
Food composites
sugars (20.8 mg/kg, range from ND to 180.6 mg/kg), vegetables (17.6 mg/kg, range from ND to 50.3 mg/kg), legumes and nuts (12.3 mg/kg, range from ND to 39.8 mg/kg), aquatic foods (10.6 mg/ kg, range from ND to 65.3 mg/kg), meats (7.6 mg/kg, range from ND to 42.9 mg/kg) and cereals (4.8 mg/kg, range from ND to 36.4 mg/kg), eggs (3.9 mg/kg, range from ND to 35.2 mg/kg). Milk (1.7 mg/kg, range from ND to 27.3 mg/kg), alcoholic beverages (1.6 mg/kg, range from ND to 9.2 mg/kg) and fruits (0.3 mg/kg, range from ND to 1.8 mg/kg) presented particularly low mean concentrations. Acrylamide was not detected in water and beverages. The highest concentration of acrylamide was found in the potato sample from Hubei province (211.8 mg/kg), followed by the sugar sample from Inner Mongolia (180.6 mg/kg) and the potato sample from Sichuan province (121.5 mg/kg). Starchy foods such as potatoes cooked at high temperatures (above 120 C) upon frying, roasting, and baking are liable to produce large amounts of acrylamide. The high acrylamide levels found in sugars were proved to be mainly derived from brown sugars by trace ability analysis. High acrylamide content in brown sugars has been reported in previous studies (Zhou et al., 2013). The levels of acrylamide measured varied considerably in the samples of the same food category between different provinces. Previous studies (Ahn et al., 2002; Becalski et al., 2003; Mottram et al., 2002) showed that several factors, including heating temperature, cooking methods and amounts of carbohydrates and amino acids, might contribute to the formation of acrylamide, which cause a large variation in the levels of acrylamide. Compared with acrylamide levels from the general European or international studies (EFSA, 2012; JECFA, 2011), the mean concentrations in Chinese TDS samples were much lower, particularly in potatoes, cereals, sugars and fruits. For French fries and potato crisps, EFSA reported the mean acrylamide concentrations in the recent year (2010) were 338 mg/kg and 675 mg/kg, respectively. The mean acrylamide concentration in potato and potato products was 532 mg/kg in the 72nd report of JECFA. However, the mean acrylamide concentration of potatoes from the 5th Chinese TDS was 34.8 mg/kg, much lower than the European level and the international level. Similarly, the mean acrylamide level of cereals sample from the 5th Chinese TDS (4.8 mg/kg) was also far lower than the international level (273 mg/kg). Although high acrylamide levels were found in brown sugars, the mean level of sugars from the 5th Chinese TDS was not high because of the low proportion of brown sugars in the composite samples, much lower than the mean concentration (332 mg/kg) of sugars reported by JECFA. Only very little acrylamide was detected in fruits (0.3 mg/kg) in the 5th Chinese TDS, while high mean acrylamide level (110 mg/kg) was found in fruits according to international data. On the 72th JECFA meeting, the global mean acrylamide levels of meats and offals (42 mg/kg), eggs (18 mg/kg), fish and seafood (64 mg/kg), vegetables (52 mg/kg), and alcoholic beverages (17 mg/kg) were reported, obviously higher than the Chinese level.
Mean
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Table 2 Estimated dietary intake of acrylamide from the 5th Chinese TDS (mg kg1 bw day1).
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consumption values in different provinces. Different dietetic habits and cooking styles among provinces could be mainly responsible for the difference. Fig. 2 showed the contributions of different food categories to the overall estimated acrylamide exposure for the Chinese population in the 5th Chinese TDS. Vegetables and cereals accounted for 35.2% and 34.3% of the acrylamide intake, respectively, thus being with no doubt the main contributors. For most provinces in China, high consumption of vegetables and cereals resulted in the most important food sources of acrylamide. However, vegetables and cereals contribution percentages greatly varied among regions. Vegetables made the largest contribution and were responsible for over half of dietary acrylamide exposure in Ningxia, Qinghai, Jiangxi, Guangxi and Guangdong, whereas over half of dietary acrylamide intake was derived from the consumption of cereals in Heilongjiang, Hebei, Henan and Inner Mongolia. Furthermore, potatoes were also considerable contributions (15.7%). Generally, other food items contributed less than 10% to the total dietary exposure. The contribution pattern of dietary acrylamide exposure for Chinese population differed from other international studies. In the recent EFSA assessment report (EFSA, 2011), the four major contributors of acrylamide exposure for adults were fried potatoes (12.9e64.6%), unspecified bread (0.2e59.3%), soft bread (0.0e21.6%) and biscuit (0.0e12.1%). Besides, JECFA reported potato chips (10e60%), potato crisps (10e22%), bread and rolls/toast (13e34%) and pastry and sweet biscuits (10e15%) as the main contributors of dietary acrylamide intake in most countries (JECFA, 2011). The difference could be explained by different dietetic habits between China and most western countries. Chinese dietary pattern is dominated by vegetables and cereals, and is inconsistent with those of the vast majority of western countries. The result of the dietary exposure assessment in this study was compared with the 3rd and the 4th Chinese TDS (Zhou et al., 2013). The mean dietary acrylamide intakes from the 3rd, the 4th and the 5th Chinese TDS were 0.188, 0.286, and 0.319 mg kg1 bw day1, respectively, and an increase with about 70% was observed from 2000 to now. The dietary intakes of acrylamide of each food category from the three Chinese TDSs were compared in Table 3. Acrylamide levels and food consumption vary in the three TDSs, both of which could lead to the differences in dietary exposure of acrylamide. Based on statistical analysis, no significant differences were found in dietary exposure and levels of acrylamide between the 4th and 5th TDSs. Because the dietary exposure of each region (not each province) was evaluated in the 3rd TDS, we cannot compare the 3rd TDS with the 4th and 5th TDSs using statistical analysis. For several main contributors, such as cereals, legumes and nuts, and potatoes, a notable increase was observed from the
The 3rd TDS
The 4th TDS
The 5th TDS
Cereals Legumes and nuts Potatoes Meat Eggs Aquatic foods Milk Vegetables Fruits Sugars Water and beverages Alcoholic beverages Total
0.049 0.013 0.023 0.001 0.000 0.001 0.000 0.101 0.001 0.000 0.000 0.002 0.188
0.076 0.016 0.023 0.019 0.000 0.006 0.000 0.136 0.001 0.002 0.001 0.000 0.286
0.109 0.018 0.050 0.015 0.002 0.007 0.001 0.112 0.000 0.001 0.002 0.000 0.319
3rd TDS to the 5th TDS. However, the dietary exposure to acrylamide from vegetables first increase and then decrease. Furthermore, the acrylamide intakes of individual provinces were compared between the 4th and 5th Chinese TDS (Fig. 3). Interestingly, a geographic change was observed. In the three provinces of South 1, there was a notable decline from the 4th and 5th Chinese TDS, whereas a considerable increase was observed in the three provinces of South 2. Dietary exposure assessments of acrylamide have been done for general population in many countries in recent years. The mean dietary acrylamide exposures for the general population around the world were also reported to be 1 mg kg1 bw day1 by JECFA (JECFA, 2011). Thus, dietary exposure of Chinese population may be at a lower level than other countries. The average dietary intake from the 5th Chinese TDS was lower than those from France (0.43 mg kg1 bw day1) (Sirot et al., 2012), the United Kingdom (0.61 mg kg1 bw day1) (Mills et al., 2008), Ireland (0.59 mg kg1 bw day1) (Mills et al., 2008), the Netherlands (0.48 mg kg1 bw day1) (Konings et al., 2003), Sweden (0.49 mg kg1 bw day1) (Svensson et al., 2003) and Poland (0.33 mg kg1 bw day1) (Mojska et al., 2010), except for Spain (0.2 mg kg1 bw day1) (Rufian-Henares et al., 2007). 3.3. Risk assessment of dietary exposure to acrylamide The overall Chinese exposure estimates yielded MOEs (based on the NOAEL of 0.2 mg kg1 bw day1) that was 628 for morphological nerve changes. For Chinese general population, the MOEs calculated based on the BMDL10 of 0.31 mg kg1 bw day1 for the induction of mammary tumors in female rats and the BMDL10 of 0.18 mg kg1 bw day1 for Harderian gland tumors in male mice were 973 and 565. These MOE values obtained in this study were
34.3%
Eggs AquaƟc foods Milk
0.3%
Vegetables
2.3%
Fruits
4.8%
Sugars 5.7%
Water and beverage Alcoholic beverage
Fig. 2. Contribution (% of Daily Intake) of the different food groups to dietary acrylamide intakes for Chinese general population.
0.9 Dietary expsoure to acrylamide (μg·kg-1 bw·day-1)
Potatoes Meat
15.7%
Food composites
Legumes and nuts 0.1%
35.2%
0.7%
Table 3 Comparison of estimated daily dietary exposure to acrylamide from different food groups from the 3rd, 4th and 5th Chinese TDS (mg kg1 bw day1).
Cereals
0.6% 0.2% 0.1%
101
0.8 0.7 0.6 0.5 0.4
The 4th TDS
0.3
The 5th TDS
0.2 0.1 0 HLJ
LN HeB SX HeN NX
SH
FJ
JX HuB SC
GX
Provinces
Fig. 3. Comparative daily intakes of acrylamide from the 4th and 5th TDS in various provinces in China.
102
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higher than those values (310 and 180) reported by JECFA. Nevertheless, compared with MOE values from the 3rd Chinese TDS (1653 and 960) and the 4th Chinese TDS (1069 and 621), a decrease was observed in the past decade. The assessment results indicated a health concern and a need to reduce acrylamide exposure in China, especially several provinces with low MOE values, such as Heilongjiang, Henan, Jilin, Inner Mongolia, Qinghai and Sichuan. It is therefore advisable to reduce dietary exposure to acrylamide by changing food processing methods and make reasonable selection of foodstuffs in daily diet for Chinese population. People should eat a balanced and varied diet, which includes plenty of fruit and vegetables, and should limit their consumption of fried foods, particularly potato chips and fried potatoes. People are advised to cook foods by steaming and boiling, not to cook them for too long or at too high a temperature, in order to reduce the formation of acrylamide (FEHD, 2013; WHO, 2002). 4. Conclusion The mean dietary exposure of acrylamide for the Chinese population is estimated to be 0.319 mg kg1 bw day1, which was relatively lower than that of the international level assessed by JECFA. However, the MOE values obtained still indicated a potential health risk. The last three Chinese TDS showed a notable upward trend in the aspect of acrylamide exposure. This study highlighted the need to continue to monitor dietary acrylamide exposure in China. Conflicts of interest The authors declare that there are no conflicts of interest. Acknowledgments We thank 20 provincial Centers for Disease Control and Prevention for sampling and dietary sample preparation. This work was supported by the National Science and Technology Support Program of China (Grant No. 2012BAK01B01). Appendix A. Supplementary data Supplementary data related to this article can be found at http:// dx.doi.org/10.1016/j.fct.2015.11.013. References Ahn, J.S., Castle, L., Clarke, D.B., Lloyd, A.S., Philo, M.R., Speck, D.R., 2002. Verification of the findings of acrylamide in heated foods. Food Addit. Contam. 19, 1116e1124. Becalski, A., Lau, B.P.Y., Lewis, D., Seaman, S.W., 2003. Acrylamide in foods: occurrence, sources, and modeling. J. Agric. Food Chem. 51, 802e808. Bull, R.J., Robinson, M., Laurie, R.D., Stoner, G.D., Greisiger, E., Meier, J.R., Stober, J., 1984. Carcinogenic effects of acrylamide in sencar and A/J mice. Cancer Res. 44, 107e111. Chen, J., Gao, J., 1993. The Chinese total diet study in 1990. Part I. Chemical contaminants. J. AOAC Int. 76, 1193e1205. European Food Safety Authority (EFSA), 2011. Results on acrylamide levels in food from monitoring years 2007 to 2009 and exposure assessment. EFSA J. 9, 2133. European Food Safety Authority (EFSA), 2012. Update on acrylamide levels in food from monitoring years 2007 to 2010. EFSA J. 10, 2938. Food and Environmental Hygiene Department (FEHD), The Government of the Hong Kong Special Administrative Region, 2013. The First Hong Kong Total Diet Study: Acrylamide. http://www.cfs.gov.hk/english/programme/programme_
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