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In our previous study, bisphenol S (BPS) was detected unexpectedly and at high levels in meat samples from 2016 and 2020 Canadian total diet study (TDS). In this study, samples of meat and meat products from 2008-2015 and 2017-2019 TDS were also analysed to investigate the consistency of BPS occurrence in meat and identify possible trends and provide some information on the potential sources for BPS in meat. BPS was detected again with the highest levels observed in samples of fresh pork (105 ng/g) and veal cutlets (140 ng/g) from the 2008 TDS. This indicates that the occurrence of BPS in meat is not a recent phenomenon but rather an existing one since 2008 or even earlier. BPS concentrations in meat samples from the 2008 to 2020 TDS varied significantly, e.g. 1.2-118 ng/g in roast beef, 1.8-140 ng/g in veal cutlets, but no trend was observed. The lack of trend for BPS over the period of 13 years (2008-2020) does not support the speculation that BPS is being used to replace BPA in food packaging, and sources other than food packaging may be possible and should be investigated for BPS.

It is already known that bisphenol S (BPS) has been used as a substitute for BPA in thermal papers in recent years. It is not clear, however, if BPS has also been used to replace BPA in can coatings as currently being speculated due to a lack of credible studies on migration of BPS from can coatings and occurrence data of BPS in foods. In this study, an LC-MS/MS method was developed for the analysis of BPS, along with several other bisphenols, and method detection limits for BPS varied from 0.0017 to 3.1 ng/g depending on the type of sample matrix and the amount of sample analysed. This method was used to analyse 159 different food composite samples from a recent Canadian total diet study. Bisphenol E (BPE), bisphenol B (BPB), and bisphenol AF (BPAF) were not detected in any of the 159 food composite samples, bisphenol F (BPF) was detected in only three samples (25-2360 ng/g), and bisphenol A (BPA) was detected in 10 samples (5.3-41 ng/g) which were all prepared from canned foods. BPS was not detected in any of the canned food composite samples but was detected in nine food composite samples prepared from meat and meat products (1.2-35 ng/g), indicating sources for BPS other than can coatings may be possible, which will be investigated in future studies.

Levels of most VOCs in foods are usually low because of their volatility, and human exposure to VOCs is expected to be mainly via inhalation of ambient and indoor air. However, dietary exposures to VOCs can be significant to overall exposures if elevated concentrations of VOCs are present in foods consumed in high amounts and/or on a regular basis, and this was demonstrated in this study with the occurrence data of toluene from the recent 2014 Canadian Total Diet Study (TDS). Concentrations of toluene in the composite samples of most food types from the 2014 TDS are low and similar to the results from the previous 2007 TDS with some exceptions, such as beef steak (670 ng/g (2014 TDS) vs. 14 ng/g (2007 TDS)), poultry, chicken and turkey (307 ng/g (2014 TDS) vs. 8.8 ng/g (2007 TDS)). Toluene concentrations in most of the grain-based and fast food composite samples from the 2014 TDS are considerably higher than those from the 2007 TDS, with the highest level of 4655 ng/g found in the composite sample of crackers from the 2014 TDS (compared to 18 ng/g from 2007 TDS). Dietary exposure estimates for toluene based on the occurrence results from the 2014 TDS show that for most of the age groups, grain-based foods are the primary source, accounting for an average of 77.5% of the overall toluene intake from the diet. The highest dietary exposures to toluene were observed for the adult age groups, with estimated average exposures ranging from 177.4 to 184.5 µg/d. Dietary exposure estimates to toluene are well below oral doses associated with toxicological effects and also below the maximum estimated intake (819 µg/d) from air inhalation for adult group (20 - 70 years) based on the results from CEPA (Canadian Environmental Protection Act) assessment in 1992.

Volatile organic compounds (VOCs) are ubiquitous in the environment due to evaporation and incomplete combustion of fuels, use of consumer and personal care products, etc. and they can accumulate in foods. Some VOCs in foods can also be formed during food processing and preparation and migrate from food packaging. In this pilot study, a GC-MS method based on headspace solid-phase microextraction (SPME) was validated and used to analyse selected individual foods which can be consumed directly and 153 different total diet composite food samples for 13 VOCs. Vinyl chloride was not detected in any of the 153 composite food samples, while the other 12 VOCs were detected at various frequencies, with m-xylene being the most frequently detected (in 151 of the 153 samples), followed by toluene (145), 1,3,5-trimethylbenzene (140), ethylbenzene (139), styrene (133), 1,2,4-trimethylbenzene (122), benzene (96), p-dichlorobenzene (95), n-butylbenzene (55), chloroform (45), naphthalene (45) and trichloroethylene (31). Concentrations of the 12 VOCs in most of the food composite samples were low, with the 90th percentiles from 1.6 ng g(-1) for n-butylbenzene to 20 ng g(-1) for toluene. However, some VOCs were detected at higher levels with maxima, for example, of 948 ng g(-1) for m-xylene and 320 ng g(-1) for ethylbenzene in chewing gum, 207 ng g(-1) for styrene and 157 ng g(-1) for toluene in herbs and spices. VOCs were detected at higher levels in most of the individual food items than their corresponding composite samples, for example, the average chloroform concentration in the individual canned soft drinks was 20 ng g(-1) compared with 3.0 ng g(-1) in their composite, and the average toluene concentration in the individual canned citrus juice was 96 ng g(-1) compared with 0.68 ng g(-1) in their composite. Thus, for determination of VOCs in foods which can be consumed directly, their individual food items should be analysed whenever possible for accurate exposure assessment.

Total mercury was measured in 156 composites prepared from 936 samples of canned tuna sold in Canada in 2006. Each composite comprised a single brand. Yellowfin tuna contained the lowest concentrations, averaging 0.066 mg/kg. Skipjack tuna contained slightly higher concentrations, averaging 0.132 mg/kg. The highest average concentration was found in the Albacore tuna: mean 0.325 mg/kg, range 0.174-0.507 mg/kg. The second highest concentration among the 49 albacore composites was 0.469 mg/kg. There were 72 composites for which the type of tuna was not specified. The mercury in these averaged 0.095 mg/kg and ranged from 0.016 to 0.237 mg/kg.

In the period from 1985 to 1999, about 600 samples of total diet foods from Canadian cites were analysed for dioxins, furans and non-ortho-PCBs. Toxic equivalent (TEQ) concentrations on a lipid basis were found to be the highest in dairy and beef products followed by poultry and pork. These levels decreased over the 15-year period of sampling, particularly those for fluid milk, less so for poultry and pork and little or no change for beef. Calculation of the human daily intake for the years 1985-1988 showed values a little less than 1 pg of TEQ(2005) polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran per kg body weight, falling progressively to less than 0.5 pg of TEQ in 1999. These estimates are lower than the 2.3 pg of TEQ currently recommended by the WHO. The main categories of foods contributing to the TEQ were animal meats and dairy products, with lesser amounts from fish and other foods.

This paper describes the design of the fourth phase of the Canadian total diet study, conducted for the period 1992-1999. During this phase, complete sets of foods were purchased from eight cities (from one of them twice). For each of the sets, individual foods were prepared as for consumption into about 140 different food composites at Kemptville College, homogenised and bottled. Water from Kemptville, Ontario, was used for the preparation of the foods. The composites were stored frozen at -20°C and then analysed in the Food Research Division for chlorinated dioxins and dibenzofurans, pesticides, PCBs and trace elements. The analytical results were combined with average food consumption values for different age/sex groups, and dietary intakes were calculated. The design of the total diet study provided information to achieve the following goals: (a) background concentrations of the chemicals in the 140 different food composites, (b) average dietary intakes of the chemicals by the population and by different age/sex groups, (c) percent contribution of individual foods and food groups to the dietary intakes, (d) identification of individual contaminated foods and (e) identification of trends in human exposure with time.

Perfluorinated compounds (PFCs) have been detected in humans worldwide and are of health concern. This study measured the concentration of PFCs in composite samples collected for the 1998 Health Canada Total Diet Study and estimated dietary exposure for the Canadian population (older than 12 years of age) using previously collected dietary data (n = 1721). PFCs were detected in 8 samples including processed meats, preprepared foods, and peppers with a range of concentrations from 0.48 to 5.01 ng g(-1) (wet weight). 6:2 fluorotelomer unsaturated carboxylate (FTUCA) was detected in cold cuts at a concentration of 1.26 ng g(-1). Mean daily PFC exposure estimates ranged from 1.5 to 2.5 ng (kg of body weight)(-1). Perfluorinated carboxylates (PFCA C(7)-C(11)) contributed more to PFC exposure than either perfluorooctane sulfonate (PFOS) or FTUCA. Total PFCAs in cakes and cookies, lunchmeats, and green vegetables were the main contributors to dietary exposure, although these exposure levels were below the provisional tolerable daily intake provided by the German Drinking Water Commission. Dietary exposure to total PFCs has not changed over time, although the contribution of PFOS to total PFC exposure may have increased between 1998 and 2004. Further research on the sources of contamination of processed and preprepared foods is required. Dietary exposure to PFCs among Canadians poses minimal health risks based on current toxicological information.

BACKGROUND: There is a lack of information on the presence of volatile organic compounds including p‐cymene in foods for dietary exposure assessment. p‐Cymene is a monoterpene found in many plant species, which has been used as a flavouring agent in foods and also exhibits antioxidant and antimicrobial properties. While the Joint FAO/WHO Expert Committee on Food Additives (JECFA) has no safety concerns at current levels of intake when used as a flavouring, the current study examines p‐cymene levels in foods in general, not just from possible uses as a flavouring, as there could still be a potential health concern if there were high levels of exposure. RESULTS: 159 food composite samples from the 2014 Canadian Total Diet Study were analysed for p‐cymene using a gas chromatographic–mass spectrometric method after headspace solid‐phase microextraction. Concentrations of p‐cymene in the composite samples of most food types were generally low, with a maximum level of 73.5 μg g−1, detected in the composite sample of herbs and spices. Dietary exposures to p‐cymene were estimated for different age groups of Canadian populations. CONCLUSIONS: Although p‐cymene was detected in various foods, estimated dietary exposures to p‐cymene for different age groups are well below the human intake threshold of toxicological concern established by JECFA of 1800 μg per person per day for structural class I flavours, which includes p‐cymene. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A sensitive and selective GC-MS method was developed and used for simultaneous analysis of di-(2-ethylhexyl) adipate (DEHA) and 20 selected phthalates in the food samples from the 2013 Canadian Total Diet Study. At least one of the 21 target chemicals was detected in 141 of the 159 different food composite samples analysed. However, only seven of the 21 target chemicals were detected, with di-(2-ethylhexyl) phthalate (DEHP) and DEHA being detected most frequently, in 111 and 91 different food composite samples, respectively, followed by di-n-butyl phthalate (DBP) (n = 44), n-butyl benzyl phthalate (BBzP) (32), di-iso-butyl phthalate (DiBP) (27), di-ethyl phthalate (DEP) (3), and di-cyclohexyl phthalate (DCHP) (1). Levels of DEP (di-ethyl phthalate), DiBP, DBP, BBzP and DCHP were low, in general, with average concentrations of 9.63, 8.26, 23.2, 12.4 and 64.9 ng g–1, respectively. Levels of DEHA and DEHP varied widely, ranging from 1.4 to 6010 ng g–1 and from 14.4 to 714 ng g–1, respectively. High levels of DEHA were found mainly in the composite samples where the individual food items used to prepare the composite were likely packaged in polyvinyl chloride (PVC) wrapping film, while the highest DEHP levels were found in the vegetable and fruit samples. [ABSTRACT FROM AUTHOR]