Dietary exposure to chloropropanols of secondary school students in Hong Kong

This paper reports levels of 3-monochloropropan-1,2-diol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) in a wide range of food items and estimates their dietary exposure for secondary school students in Hong Kong. Dietary exposure to chloropropanols was estimated using local food consumption data obtained from secondary school students in 2000 and the concentrations of 3-MCPD and 1,3-DCP in food samples taken from the local market. The dietary exposure to 3-MCPD for an average secondary school student consumer was estimated to be 0.063–0.150 µg kg^?1 body weight (bw) day^?1, whilst that for the high consumer was 0.152–0.300 µg kg^?1 bw day^?1. Both estimates fell below the provisional maximum tolerable daily intake of 2 µg kg^?1 bw established by the Joint Expert Committee on Food Additives (JECFA) and amounted to less than 20% of this safety reference value. The dietary exposure to 1,3-DCP for an average secondary school student consumer was estimated to be 0.003–0.019 µg kg^?1 bw day^?1, whilst that for the high consumer was 0.009–0.040 µg kg^?1 bw day^?1. The resulting margins of exposures were of low concern for human health. It could be concluded that both the average and high secondary school student consumers were unlikely to experience major toxicological effects of 3-MCPD and 1,3-DCP.     

Evaluating daily exposure to polychlorinated biphenyls and polybrominated diphenyl ethers in fish oil supplements

Fish oil supplements have become a popular means of increasing one's dietary intake of essential polyunsaturated fatty acids. However, there is growing concern that the levels and potential health effects of lipophilic organic contaminants such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may diminish some of the health benefits associated with the daily consumption of fish oil supplements. In this study, ten over-the-counter fish oil supplements available in the United States were analysed for PCBs and PBDEs and daily exposures calculated. Based on manufacturers’ recommended dosages, daily intakes of PCBs and PBDEs ranged from 5 to 686 ng day^?1 and from 1 to 13 ng day^?1, respectively. Daily consumption of fish oil supplements expose consumers to PCBs and PBDEs. However, in comparison with fish ingestion, fish supplements may decrease daily PCB exposure and provide a safer pathway for individuals seeking to maintain daily recommended levels of polyunsaturated fatty acids.     

Dietary exposure of secondary school students in Hong Kong to benzoic acid in prepackaged non-alcoholic beverages

This study evaluated the dietary exposure of secondary school students in Hong Kong to benzoic acid from pre-packaged non-alcoholic beverages. Exposure was estimated using local food consumption data of secondary school students obtained by a semi-quantitative food frequency questionnaire in 2000 and the benzoic acid level detected in pre-packaged beverages, including soft drink (both diet/light and regular types), fruit juice, soy milk, Chinese tea and coffee/tea) available locally in late 2006. The estimated dietary exposure to benzoic acid from pre-packaged beverages of average and high consumers (95^th percentile) was 0.31 and 0.97 mg kg^?1 bw day^?1, respectively. These exposures accounted for 6.1 and 19.3% of the acceptable daily intake (ADI: 0–5 mg kg^?1 bw) of benzoic acid for average and high consumers, respectively. As in other countries, soft drinks contributed most to dietary exposure to benzoic acid from pre-packaged beverages in Hong Kong.     

Contamination of food samples from Malaysia with polychlorinated dibenzo-p-dioxins and dibenzofurans and estimation of human intake

A total of 126 food samples, categorised into three groups (seafood and seafood products, meat and meat products, as well as milk and dairy products) from Malaysia were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The concentration of PCDD/Fs that ranged from 0.16 to 0.25 pg WHO₀₅-TEQ g^?1 fw was found in these samples. According to the food consumption data from the Global Environment Monitoring System (GEMS) of the World Health Organization (WHO), the dietary exposures to PCDD/F from seafood and seafood products, meat and meat products, as well as milk and dairy products for the general population in Malaysia were 0.064, 0.183 and 0.736 pg WHO₀₅-TEQ kg^?1 bw day^?1, respectively. However, the exposure was higher in seafood and seafood products (0.415 pg WHO₀₅-TEQ kg^?1 bw day^?1) and meat and meat products (0.317 pg WHO₀₅-TEQ kg^?1 bw day^?1) when the data were estimated using the Malaysian food consumption statistics. The lower exposure was observed in dairy products with an estimation of 0.365 pg WHO₀₅-TEQ kg^?1 bw day^?1. Overall, these dietary exposure estimates were much lower than the tolerable daily intake (TDI) as recommended by WHO. Thus, it is suggested that the dietary exposure to PCDD/F does not represent a risk for human health in Malaysia.     

Risk assessment of dietary exposure to tryptamine for the Austrian population

ABSTRACT

Tryptamine acts as a neuromodulator and vasoactive agent in the human body. Dose–response data on dietary tryptamine are scarce and neither a toxicological threshold value nor tolerable levels in foods have been established so far. This paper reviews dose–response characteristics and toxicological effects of tryptamine as well as tryptamine contents in food, estimates dietary exposure of Austrian consumers, and calculates risk-based maximum tolerable limits for food categories. A dose without effect of 8 mg kg^?1 body weight day^?1 was derived from literature data. Dietary exposure via fish/seafood, beer, cheese and meat products was estimated for Austrian schoolchildren, female and male consumers, based on 543 food samples analysed in Austria 2010–15 and on food consumption data from 2008. Even worst-case estimates based on very high tryptamine contents reported in the literature did not exceed 5.9 mg kg^?1 body weight day^?1, and thus were below the dose without effect. Maximum tolerable levels for food commodities were calculated for high-consumption scenarios (95th percentile of female Austrian consumers). For fresh/cooked fish, preserved fish, cheese, raw sausage, condiments, sauerkraut and fermented tofu, maximum tolerable levels were 1650, 3200, 2840, 4800, 14,120, 1740 and 2400 mg kg^?1, respectively. For beer, the maximum tolerable limit of 65 mg kg^?1 included an uncertainty factor of 10. None of the Austrian occurrence data exceeded these levels (in fact, only 3.3% of samples demonstrated measurable amounts of tryptamine), and just one report was found in the literature on a raw fish sample exceeding the respective tolerable level. In sum, dietary intake of tryptamine should not cause adverse health effects in healthy individuals. The assessment did not take into account the combined effects of simultaneously ingested biogenic amines, and increased susceptibility to tryptamine, e.g., due to reduced monoamine oxidase activity.     

Dietary exposure to non-dioxin-like PCBs of the Hong Kong adult population from a total diet study

Dietary exposure of Hong Kong adults to the sum of the six indicator PCBs (Σ₆ PCBs; PCB 28, 52, 101, 138, 153, and 180) was estimated in this study using the Total Diet Study (TDS) approach. Seventy one commonly-consumed food items of animal origin were sampled in four seasons and prepared as consumed in 2010–2011. The results showed that the main dietary source of Σ₆ PCBs to the adult population was ‘fish, seafood and their products’ which accounted for 84.3% of the total exposure. About 50% of the total exposure was contributed by four fish species: salmon (cooked salmon and salmon sashimi, 19.9%), mandarin fish (14.7%), pomfret fish (8.5%) and yellow croaker (7.5%). Salmon was found to contain the highest mean level of Σ₆ PCBs of 5.7 ng g^?1 fresh weight at upper bound estimation, ranging from 4.4 to 6.3 ng g^?1. The lower bound and upper bound exposure estimates of ?₆ PCBs to the average consumer of the population were found to be 0.68 and 1.38 ng kg^?1 body weight day^?1 respectively while for high consumers, the lower bound and upper bound exposure estimates were 3.08 and 3.84 ng kg^?1 body weight day^?1 respectively. In addition, the dietary exposures to individual indicator PCB congeners were also estimated.     

Polybrominated diphenyl ethers (PBDEs) in US meat and poultry: 2012–13 levels,trends and estimated consumer exposures

ABSTRACT

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants whose use has contaminated foods and caused subsequent human exposures. To address the issue of possible human exposure, samples from a 2012–13 US meat and poultry (beef, pork, chicken, turkey) study were analysed for seven PBDEs. The mean summed concentrations of the seven BDE congeners (ΣPBDE) from beef, pork, chicken and turkey were 0.40, 0.36, 0.19, and 0.76 ng g^–1 lipid weight (lw). The range of ΣPBDEs for all meat classes was 0.01–15.78 ng g^–1 lw. A comparison of this study with a 2007–08 study revealed a decline in the median ΣPBDEs for all four meat classes, a reduction of 25.9% to 70.0%, with pork, chicken and turkey PBDE residues being statistically lower relative to the 2007–08 study. BDEs 47 and 99 contributed the most to the ΣPBDE concentrations, indicating likely animal exposures to the penta-BDE formulation. Based on the reported data an estimate of US consumer daily intake of PBDEs from meat and poultry was 6.42 ng day^–1.     

Dietary exposure of the Hong Kong adult population to polybrominated diphenyl ethers (PBDEs): results of the first Hong Kong Total Diet Study

Polybrominated diphenyl ethers (PBDEs) are a group of industrial chemicals that are persistent and can bioaccumulate. In the first Hong Kong Total Diet Study, the dietary exposure of Hong Kong adults to PBDEs was estimated to assess the associated health risks. Food samples, which represented the Hong Kong people’s diet, were collected and prepared in table-ready form for analysis. Concentrations of PBDEs were determined in 142 composite samples. The dietary exposures were estimated by combining the analytical results with the local food consumption data of the adults. The mean and 95th percentile of dietary PBDEs exposures of the Hong Kong people were 1.34 and 2.90 ng kg^?1 body weight day^?1, respectively. The main dietary source of PBDEs was “fish and seafood and their products”, which contributed 27.3% of the total exposure, followed by “meat, poultry and game and their products” (20.7%), “cereals and their products” (15.9%), and “fats and oils” (15.9%). The large margins of exposure (MOE) (>2.5) calculated following the European Food Safety Authority (EFSA) approach for four important congeners, BDE-47, BDE-99, BDE-153 and BDE-209, indicate that the estimated dietary exposures are unlikely to be a significant health concern.     

Seasonal and geographical variations in levels of polychlorinated biphenyls (PCB) and polybrominated diphenyl ethers (PBDE) in Polish butter fat used as an indicator of environmental contamination

The aim of this study was to evaluate the seasonal variation/geographical distribution of environmental concentration of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) across Poland using butter fat as an indicator of the contaminants. The average concentration of six indicator PCBs determined in the studied samples was 1500?pg?g^–1 fat. The average concentration of 12 dioxin-like PCBs expressed as lower-bound dioxin-equivalent toxicity was 0.684 pg TEQ g^?1 fat. The average total concentration of 14 investigated PBDE congeners was 105?pg?g^?1 fat. Statistically significant concentration differences between summer and winter samples were found. The results of this study indicate also a significant geographical diversification of butter contamination reflecting regional differences in environmental contamination. The seasonal variation of PBDE profiles evidences transformation of PBDE within the environment.     

Dietary intake estimations of polybrominated diphenyl ethers (PBDEs) based on a total diet study in Osaka,Japan

This study presents the results of a total diet study performed for estimating the dietary intake of polybrominated diphenyl ethers (PBDEs) in Osaka, Japan. The concentrations of 36 PBDEs were measured in samples from 14 food groups (Groups I–XIV). PBDEs were detected only in Groups IV (oils and fats), V (legumes and their products), X (fish, shellfish, and their products), and XI (meat and eggs) at concentrations of 1.8, 0.03, 0.48, and 0.01 ng g^?1, respectively. For an average person, the lower bound dietary intakes of penta- and deca-formulations were estimated to be 46 and 21 ng day^?1, respectively. A high proportion of the decabrominated congener (DeBDE-209) was observed in Group IV. To confirm the presence of DeBDE-209 in vegetable oils, an additional analysis was performed using 18 vegetable oil samples. Of these, seven contained ng g^?1 levels of DeBDE-209.     

Non-dioxin-like PCB and PBDE deposition on Zea mays L. leaves: modelled contamination in milk from dairy animals fed on silage

Maize (Zea mays L.) can intercept airborne pollutants before their deposition on soil. Selected non-dioxin-like polychlorinated biphenyls (Σ₆NDL-PCBs) and polybrominated diphenyl ethers (Σ₈PBDEs) with feed and food safety relevance were measured on maize leaves harvested for silage in dairy animals from 28 fields in Italy. Analyses were carried out by gas chromatography coupled to high- and low-resolution mass spectrometry. Contamination ranged from 0.65 to 5.3 ng g^?1 with 12% moisture for Σ₆NDL-PCBs, and from 2.7 to 6.2 for Σ₈ PBDEs. Modelled contamination in cow’s milk was estimated to fall within the range 0.27–16 ng g^?1 for PCBs, 0.17–1.9 for PBDE number 47, and 0.22–2.1 for PBDE number 99 on a lipid basis. The results indicate that maize silage alone may raise Σ₆NDL-PCB contamination in dairy milk up to the 95th percentile in the European Union. Results are discussed in terms of air quality standards able to support food safety.     

A preliminary comparison of polybrominated diphenyl ether concentrations relative to lipid content and to levels of dioxins and dioxin-like polychlorinated biphenyls in Norwegian farmed Atlantic salmon (Salmo salar)

Polybrominated diphenyl ethers (PBDEs) are environmental contaminants structurally similar to polychlorinated biphenyls (PCBs), and correlations between PBDE concentrations and concentrations of lipid, PCBs, dioxins and furans in feed and farmed Atlantic salmon filet indicate PBDEs may be derived from similar sources. PBDE concentrations (3.9 ± 0.6 ng g^?1 wet wt) in farmed Atlantic salmon correlated well with lipid content and these other halogenated contaminants, however, lower concentrations of PBDEs (1.6 ± 0.3 ng g^?1 wet wt) showed no correlation. Possible explanations for the non‐linear behaviour of PBDE concentrations in Atlantic salmon are discussed.     

Levels and distribution of PBDEs and PFASs in pork from different European countries

ABSTRACT

Meat and meat products are included in a great number of human diets. However, the great consumption of meat needs to be controlled for the presence of traces of contaminants. The European Commission has not stated maximum limits for some environmental pollutants such as the perfluoroalkyl substances (PFASs) and polybrominated diphenyl ether (PBDE); the European Food Safety Authority (EFSA) Scientific Panel has recommended that more occurrence data for PFASs in food should be collected to improve the accuracy of future exposure calculations. Therefore, the distribution of PFASs and PBDEs trace contaminants from eight EU Member States were investigated through liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) and Gas Chromatography-Mass Spectrometry (GC-MS/MS). No PFASs were detected, except perfluorooctanoic acid, in only one Austrian sample at the concentration of 0.531 ng g^?1. PBDEs were detected in 3 out of 77 samples: one from Germany showed the presence of all congeners analysed in the concentration range 0.53–0.77 ng g^?1, the others, from Netherland and Italy, respectively contained PBDE 153 (0.53 ng g^?1) and PBDE 100 (0.62 ng g^?1). The results show that the analysed samples do not pose a risk for human beings in regard to PFASs and PBDEs. Further studies are needed to keep monitoring their presence in foodstuff, as it has been suggested by European Commission.     

Dietary exposure of Hong Kong adults to fatty acid esters of 3-monochloropropane-1,2-diol

A total of 290 individual food samples were collected in Hong Kong, China, for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters analysis. Most samples were processed food and in ready-to-eat form. The results show that the levels of 3-MCPD fatty acid esters were high in biscuits, fats and oils, snacks and Chinese pastry with mean bound 3-MCPD levels of 440, 390, 270 and 270 μg kg^?1, respectively. The dietary exposures to bound 3-MCPD of average and high adult consumers were estimated to be 0.20 and 0.53 μg kg bw^?1 day^?1, respectively. The primary toxicological concern of 3-MCPD fatty acid esters is its potential to release 3-MCPD in vivo during digestion in the gastrointestinal tract. 3-MCPD would affect the kidney, the central nervous system and the male reproductive system of rats. Assuming that 100% of the 3-MCPD was released from 3-MCPD fatty acid esters by hydrolysis in the digestive system, the dietary exposures to 3-MCPD for average and high adult consumers were only 10% and 26% of the provisional maximum tolerable daily intake (PMTDI) of 3-MCPD established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) (2 μg kg bw^?1 day^?1), respectively. The results suggest that both average and high adult consumers are unlikely to experience major toxicological effects of 3-MCPD.     

Dietary intake assessment of caramel colours and their processing by-products 4-methylimidazole and 2-acetyl-4-tetrahydroxy-butylimidazole for the Chinese population

ABSTRACT

The aim of the study was to assess the dietary intake of caramel colours and their by-products 4-methylimidazole (4-MEI) and 2-acetyl-4-tetrahydroxybutylimidazole (THI) for the Chinese population. Based on the typical and maximum reported use levels of caramel colours in 15 food categories, the dietary intakes of combined and single-class caramel colours of Classes I, III and IV were estimated with the food consumption data from the China National Nutrient and Health Survey. Using the mean values of 4-MEI and THI contents in Class III and Class IV Caramel colour samples, the exposures to 4-MEI and THI from dietary caramel colours were derived. The results showed that the combined and individual average dietary caramel colour intakes for the Chinese population of different age groups were estimated to be 232–60.3 mg kg^?1 bw day^?1 for combined caramels, 5.9–29.2 mg kg^?1 bw day^?1 for Class I, 7.7–29.6 mg kg^?1 bw day^?1 for Class III, 21.2–54.3 mg kg^?1 bw day^?1 for Class IV, which were far below the group acceptable daily intake (ADI) and respective ADIs. The combined intake of 4-MEI from Class III and IV caramel colours was estimated to be 3.8–5.2 μg kg^?1 bw day^?1 on average, and 12.9–27.1 μg kg^?1 bw day^?1 at 95th-97.5th percentile for the general population. The anticipated exposure to THI from Class III caramel colours was estimated to be 0.1–0.3 μg kg^?1 bw day^?1 on average and 0.5–1.7 μg kg^?1 bw day^?1 at 95th–97.5th percentile for the general population. The dietary caramel colours intakes and the exposures to 4-MEI and THI from dietary caramel colour for the Chinese population were considered to be of low health concern based on the present toxicological data. Soy sauce, vinegar and compound seasonings were found to be the main contributors to the dietary intake of caramel colours.     

Dietary exposure of Hong Kong secondary school students to total mercury and methylmercury from fish intake

Fish is the main source of dietary exposure to methylmercury (MeHg), which is a public health concern owing to its potential neurotoxicity. To evaluate the public health risk, this study estimated the total mercury (tHg) and MeHg exposure from fish intake in Hong Kong secondary school students. Median tHg and MeHg concentrations of 280 samples purchased from different commercial outlets (covering 89 species of whole fish and three types of canned tuna), together with the local food consumption data of secondary school students obtained by semi-quantitative food frequency questionnaire in 2000, were used to estimate dietary exposure from fish intake for the average and high consumer (95th percentile exposure). For tHg, the median concentration was 63 µg kg^–1 (range 3–1370 µg kg^–1) and estimated exposures ranged 0.5–0.6 µg kg^–1 body weight (bw) week^–1 for an average consumer and 1.6–1.9 µg kg^–1 bw week^–1 for a high consumer. For MeHg, median concentration was 48 µg kg^–1 (range 3–1010 µg kg^–1) and estimated dietary exposures were 0.4–0.5 µg kg^–1 bw week^–1 for an average consumer and 1.2–1.4 µg kg^–1 bw week^–1 for a high consumer. These values are below the respective provisional tolerable weekly intake (PTWI) established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA). The health risk is greater for high consumers since MeHg exposures may approach or exceed the PTWI when other dietary sources are taken into account.     

Dietary exposure to antimony,lead and mercury of secondary school students in Hong Kong

The aim of this first study was to determine the dietary exposure of antimony, lead, mercury in foodstuffs consumed by secondary school students in Hong Kong. Around 100 composite food items were purchased and then cooked prior to analysis. Antimony was measured by hydrogen generation (HG)/inductively coupled plasma–mass spectrometry (ICP–MS), while lead was determined by ICP–MS. Total mercury was measured by cold vapour atomic absorption spectrometry. The detection limits for antimony, lead and total mercury were 1, 0.6 and 3 µg kg^?1, respectively. The dietary intake of antimony, lead and total mercury for an average secondary student were estimated to be 0.252, 1.98 and 0.92 µg (kg bw)^?1 week^?1, respectively. The dietary intake of antimony, lead and total mercury for high-consumer secondary student were estimated to be 0.567, 5.09 and 2.33 µg (kg bw)^?1 week^?1, respectively. The main contribution to antimony, lead and mercury were milk, vegetables and seafood, respectively. The Tolerable Daily Intake (TDI) of antimony, as recommended by WHO, is 6 µg (kg bw)^?1 week^?1, while the Provisional Tolerable Weekly Intakes (PTWI) of lead and mercury, as recommended by JECFA, are 25 and 5 µg (kg bw)^?1 week^?1, respectively. The estimated exposure values for secondary school students were compared to these safety reference values. For the relevant population, this study confirms the low probability of health risks from these metals via food consumption.     

Dietary intake of dioxins in Japan in 2016 with time trends since 1998

Total diet samples collected from seven regions throughout Japan in 2016 were analysed for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls (DL-PCBs), known collectively as dioxins. This led to estimates of the latest dietary intake of these contaminants for the general Japanese population (≥1 year old). The average daily intake of dioxins for a person weighing 50 kg, calculated at non-detected congener concentrations assumed to be equal to zero, was estimated to be 0.54 pg TEQ (toxic equivalents) kg^?1 body weight (bw) day^?1. This value is well below the tolerable daily intake of 4 pg TEQ kg^?1 bw day^?1 for dioxins in Japan. The average intake was highest from fish and shellfish, followed by meat and eggs. The TEQ contribution of the fish and shellfish group to the total dietary TEQs was significant (89%). The DL-PCBs accounted for about 67% of the dioxin intake. The latest dioxin intake level was compared with previous estimates from total diet study results obtained annually since 1998 to determine the time trends in the dietary intake of dioxins in Japan. Overall, the average dioxin intake appeared to be decreasing gradually during the period of study. The previous average intakes of dioxins ranged from 0.58 to 1.9 pg TEQ kg^?1 bw day^?1. The latest average intake was the lowest since 1998 and was about one-third of the average intake in 1998. This decreasing trend in the dietary intake of dioxins was mainly influenced by the decreased dioxin intakes from two food groups, fish and shellfish, and meat and eggs.     

Dietary exposure of Hong Kong adults to nitrate and nitrite from vegetable intake

The aim of this study was to assess the dietary exposure of adults in Hong Kong to nitrate and nitrite from vegetables. If all vegetables consumed were raw, the dietary exposure to nitrate for average consumers was estimated to be 4.4?mg?kg^?1 body weight (bw)?day^?1 and, for high consumers, was estimated to be 13?mg?kg^?1?bw?day^?1, which is about 120 and 350% of acceptable daily intake (ADI), respectively. If all vegetables consumed were cooked, the dietary exposure to nitrate from vegetables for the average adult consumer was estimated to be 3.5?mg?kg^?1?bw?day^?1 and, for high consumer, was estimated to be 10?mg?kg^?1?bw?day^?1, which is about 95 and 270% of ADI, respectively. On the other hand, the dietary exposure to nitrite from vegetables for average and high consumers were well below the ADI.     

Decreasing concentrations of PCDD/Fs in pork based on Korean monitoring in years 2002 and 2005

The congener-specific profiles of PCDD/Fs in domestic and imported pork monitored in South Korea in years 2002 and 2005 were compared. Total concentrations of PCDD/Fs decreased from 2002 to 2005, but displayed a similar pattern of congeners. In neither 2002 nor 2005 were either 2,3,7,8-TCDD or 2,3,7,8-TCDF detected. The mean concentrations of PCDD/Fs in domestic and imported pork were 8.29 pg g^?1 fat from 106 samples in 2002 and 4.03 pg g^?1 fat from 90 samples in 2005. However, the contribution of PCDDs increased about four times with respect to toxic equivalent (TEQ) level and about 1.5 times in terms of concentration in the monitoring results from 2005 compared with 2002, and the PCDF contribution decreased substantially. This suggests that the main source of dioxins in pork probably changed to a larger portion coming from animal feeds than environmental sources of exposure. The estimated human intakes of PCDD/Fs originating from pork in the South Korean diet were calculated as 0.029 and 0.019 pg TEQ kg^?1 body weight day^?1 for the upper bound exposure in 2002 and 2005, respectively. The values represent low intakes when compared with the both Korean tolerable daily intake (TDI) (4 pg TEQ kg^?1 body weight day^?1) and World Health Organization TDI (1–4 pg TEQ kg^?1 body weight day^?1).