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As an alternative to bisphenol A (BPA), bisphenol S (BPS) has been used as an ink developer in thermal paper products including price labels on food packaging which have been suggested as the sources of BPS found at high levels in packaged fish samples. BPS in the printed price labels glued onto the outside of plastic film could migrate indirectly from the printed surface through the paper, adhesive and film into the food. In order to investigate if price labels could also be the sources of BPS detected in the meat samples in our previous studies, meat and other food samples packaged under different conditions were collected, and BPS in these samples together with the price labels on the corresponding packaging were extracted with solvent followed by solid phase extraction and stable isotope dilution LC-MS/MS analysis. BPS was detected at very high levels (161.7-222.4 µg/cm2) in all the five sticker type of price labels, indicating BPS being the dominant if not the sole ink developer. BPS was also detected in all the 26 continuous roll type of price labels but at very low levels (0.017-18 ng/cm2), indicating that the dominant ink developer is likely one of the other alternatives, rather than BPS. Despite BPS being detected in all price labels on packaging of fish, meat, and cheese samples, BPS was not detected or detected in only a few fish, meat, and cheese samples at levels considerably lower than the current EU specific migration limit (SML) of 50 ng/g food for BPS authorised under Regulation (EU) 10/2011.
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BACKGROUND: As one of the speculated bisphenols to replace bisphenol A (BPA), bisphenol F (BPF), naturally present in mustard, is structurally similar to BPA and may have similar estrogenic activity, but information on its toxicity is very limited compared to BPA. OBJECTIVE: In order to support the toxicology study of BPF at Heath Canada, a gas chromatography (GC) with mass spectrometry (MS) method based on solid phase extraction and derivatization was developed for analysis of BPF in liver samples. METHODS: Samples were treated with ß-glucuronidase to convert BPF glucuronide to free BPF for analysis of total BPF. RESULTS: The method was validated for free BPF at different spiking levels, and recoveries ranged from 90.0-97.5% with relative standard deviations from 0.11-5.54%. The method was also validated for glucuronide-conjugated BPF at different spiking levels of BPF mono-ß-D-glucuronide, recoveries ranged from 72.3-93.3% with relative standard deviations from 1.7-8.94%. The method was used to analyse 60 liver tissue samples from the rats dosed with BPF at different levels in a toxicology study. Free and glucuronide-conjugated BPF were not detected in any of the control samples which were not dosed with BPF (average method detection limit: 0.31 ng/g), but detected in all the other liver tissue samples with levels increasing at higher doses. The percent of glucuronide-conjugated BPF in total BPF varied among the liver samples, from as low as 9.8% to as high as 77.9%, indicating the importance of analysing biological samples for BPF in both free and conjugated forms for total exposure. CONCLUSION: A GC-MS method based on solid phase extraction and derivatization was developed for analysis of both free and glucuronide-conjugated BPF in liver samples. This method was validated not only for free BPF, but also for mono-ß-D-glucuronide conjugated BPF for the first time to confirm the efficiency of the deconjugation procedure with enzyme. HIGHLIGHTS: This method can be adapted and applied for analysis of free and glucuronide-conjugated BPF in other biological samples with appropriate validation in target sample matrices.
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Chloroform or trichloromethane is one of the trihalomethanes formed during disinfection of water with chlorine, and residues of chloroform can be detected in foods and food products due to the use of chlorinated drinking water and disinfecting food processing equipment with chlorine-based disinfectants. In this study, chloroform was detected in 37 (or 23%) of the 159 composite food samples from the 2014 Canadian Total Diet Study, but was not detected in cereals, fruits, fast foods, and most of the meat samples. Chloroform was detected in almost all 14 composite samples of dairy products, with the highest level (58 ng/g) observed in butter, followed by cream (26 ng/g), and cheese (12-21 ng/g). Chloroform was detected in tap water (23 and 29 ng/g) and most of the beverage samples, but concentrations were lower than those reported in other studies possibly due to evaporation during the preparation of the composite samples. Dietary exposures to chloroform are higher for younger age groups (0.51-1.41 µg/kg body weight/day) than for adults (0.25-0.42 µg/kg body weight/day). Drinking water contributed most to daily intakes for all age groups, accounting for between 62% and 86% of the total chloroform dietary intakes.
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Cloroformo , Agua Potable , Adulto , Humanos , Exposición Dietética , Canadá , Cloro , Dieta , Frutas , Peso CorporalRESUMEN
It is known that the industry already abandoned the use of bisphenol A (BPA)-based epoxy resins as internal coatings for some canned food products (e.g. infant formula, soups). The presence of bisphenol A (BPA) in foods has also been extensively investigated, especially since late 2000. However, information on temporal trends of BPA occurrence in foods is very limited. It is not clear if BPA-based epoxy resins are still being used in internal coating for many other canned foods and if the overall exposure to BPA through consumption of canned foods has significantly decreased. As part of the Canadian total diet study (TDS) program, we have been analysing food samples for BPA since 2008. In this study, results of BPA in samples of different composite canned foods from 2008-2020 TDS were reported. Clear temporal trends were observed for canned fish and soups, with BPA levels being significantly reduced since 2014 for canned fish products and 2017 for canned soups. Temporal trends were not observed for canned evaporated milk, luncheon meats, and vegetables, with even the highest levels of BPA being detected in recent samples for evaporated milk (57 ng/g), luncheon meats (56 ng/g), and baked beans (103 ng/g). This seems to indicate that BPA-based epoxy resins are still being used in the internal coatings for these canned foods products. Thus, analysis of canned food samples for BPA should be continued for exposure assessment.
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Resinas Epoxi , Alimentos en Conserva , Animales , Canadá , Alimentos en Conserva/análisis , Verduras , Compuestos de Bencidrilo/análisis , Contaminación de Alimentos/análisisRESUMEN
Intermediate volatile organic compounds (IVOCs) have recently been characterized for their contributions to the formation of secondary organic aerosol in atmospheric air. However, IVOCs in air in various indoor environments have not been characterized yet. In this study, we characterized and measured IVOCs, volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), in residential indoor air in Ottawa, Canada. IVOCs, including n-alkanes, branched-chain alkanes (b-alkanes), unspecified complex mixtures (UCM) IVOCs, and oxygenated IVOCs (such as fatty acids), were found to have a large impact on indoor air quality. The results indicate that the indoor IVOCs behave differently from those in the outdoor environment. IVOCs in the studied residential air ranged from 14.4 to 69.0 µg/m3, with a geometric mean of 31.3 µg/m3, accounting for approximately 20% of the total organic compounds (IVOCs, VOCs and SVOCs) in indoor air. The total b-alkanes and UCM-IVOCs were found to have statistically significant positive correlations with indoor temperature but have no correlations with airborne particulate matter less than 2.5 µm (PM2.5) as well as ozone (O3) concentration. However, indoor oxygenated IVOCs behaved differently from b-alkanes and UCM-IVOCs, with a statistically significant positive correlation with indoor relative humidity but no correlation with other indoor environmental conditions.
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Contaminantes Atmosféricos , Contaminación del Aire Interior , Compuestos Orgánicos Volátiles , Compuestos Orgánicos Volátiles/análisis , Contaminación del Aire Interior/análisis , Contaminantes Atmosféricos/análisis , Canadá , Alcanos , Monitoreo del Ambiente/métodosRESUMEN
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.
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Compuestos de Bencidrilo , Dieta , Animales , Compuestos de Bencidrilo/análisis , Canadá , Bovinos , Embalaje de Alimentos , Carne/análisisRESUMEN
In this study, the occurrence of bisphenol S (BPS) in the meat and meat products from a recent Canadian Total Diet Study (TDS) was investigated in more detail. In addition to their composite samples, the individual raw meat and meat products were also analysed for BPS to investigate the variations of BPS levels and provide some information on the potential sources for BPS in meat. BPS was detected in all the 11 composite samples of different meat and meat products, with the highest level in roast beef (118.23 ng/g) and lowest in cured pork (0.14 ng/g) and cold cuts luncheon meats (0.18 ng/g). BPS was also detected in all the 84 individual raw meat and meat products, with the highest level of 257.61 ng/g in roast beef, followed by 190.41 ng/g in organ meats, 110.15 ng/g in beef steak, 27.91 ng/g in veal cutlets, 17.63 ng/g in wieners & sausages, and 15.27 ng/g in ground beef. However, significant variations of BPS levels were observed in the individual meat and meat product samples under the same category collected from different stores. This may indicate that packaging is unlikely the sources for BPS in meat otherwise BPS levels would have been more or less the same with the same type of packaging (Styrofoam and cling film) regardless where they were collected. Thus, sources other than food packaging, such as the contaminated feed and farming environment (e.g. grass) for animals (e.g. cow), may be possible and should be investigated in future studies.
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Productos de la Carne , Animales , Canadá , Bovinos , Femenino , Carne/análisis , Productos de la Carne/análisis , Fenoles/análisis , SulfonasRESUMEN
BACKGROUND: Although more information has become available on the occurrence of phthalates and di(2-ethylhexyl) adipate (DEHA) in foods including cow's milk, information on their presence in human milk, the important and recommended sole diet for infants up to six months of age, is very limited, especially for DEHA. OBJECTIVE: To develop a GC-MS method for simultaneous analysis of DEHA and phthalates in human milk samples and generate occurrence data for exposure assessment. METHOD: Human milk samples were extracted with acetonitrile followed by dispersive solid-phase extraction and GC-MS analysis. RESULTS: Among the 305 human milk samples collected from the Canadian Maternal-Infant Research on Environmental Chemicals Study, some phthalates (DHxP, BBzP, and DOP) were not detected in any of the samples, while DEHA and the other phthalates (DMP, DEP, DBP, DiBP, and DEHP) were detected at low frequencies with levels from 30.4-237 ng/g in up to 31 of the 305 human milk samples. CONCLUSIONS: In general, DEHA and phthalates were detected at low frequencies and low levels in the 305 human milk samples. HIGHLIGHTS: A GC-MS method based on dispersive solid phase extraction was developed for analysis of DEHA and eight phthalates in 305 human milk samples for exposure assessment.
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Leche Humana , Ácidos Ftálicos , Adipatos/análisis , Canadá , Dieta , Cromatografía de Gases y Espectrometría de Masas , Humanos , Lactante , Leche Humana/química , Ácidos Ftálicos/análisisRESUMEN
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.
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Compuestos de Bencidrilo/análisis , Dieta , Contaminación de Alimentos/análisis , Fenoles/análisis , Sulfonas/análisis , Cromatografía Liquida , Exposición Dietética , Análisis de los Alimentos , Espectrometría de Masas en TándemRESUMEN
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.
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Antioxidantes/análisis , Exposición Dietética/análisis , Monoterpenos/análisis , Adolescente , Adulto , Anciano , Animales , Antioxidantes/metabolismo , Canadá , Niño , Preescolar , Cimenos , Grano Comestible/química , Grano Comestible/metabolismo , Comida Rápida/análisis , Femenino , Aromatizantes/análisis , Aromatizantes/metabolismo , Frutas/química , Frutas/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Humanos , Lactante , Masculino , Carne/análisis , Persona de Mediana Edad , Monoterpenos/metabolismo , Verduras/química , Verduras/metabolismo , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/metabolismo , Adulto JovenRESUMEN
Low levels of styrene may be found in foods as a result of possible migration from polystyrene-based food packaging and as a result of its formation during the biodegradation of a wide variety of naturally occurring compounds with structures similar to styrene. In this study, composite food samples from a recent (2014) Canadian Total Diet Study were analysed for styrene, and levels of styrene in samples of most food types were low in general with a few exceptions (e.g. 4934 ng/g in herbs and spices). Dietary exposures to styrene were estimated for different age-groups based on the occurrence data and the food consumption data for all persons, and they are 0.17-0.38 µg/kg body weight/day for children and 0.12-0.16 µg/kg body weight/day for adults, similar to air intakes (0.085-0.27 µg/kg body weight/day). Thus, for the general population, both food and air contribute similar portions of the total daily intake of styrene for all age groups. However, for the smoking population, intakes from cigarettes are still the major route of exposure to styrene.
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Exposición Dietética/análisis , Contaminación de Alimentos/análisis , Estireno/análisis , Canadá , Encuestas sobre Dietas , Exposición a Riesgos Ambientales , Embalaje de Alimentos , HumanosRESUMEN
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.
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Dieta , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente , Contaminación de Alimentos/análisis , Tolueno/análisis , Canadá , HumanosRESUMEN
Solid phase extraction (SPE) of large volumes of water and beverage products was investigated for the GC-MS analysis of bisphenol A (BPA), bisphenol AF (BPAF), bisphenol F (BPF), bisphenol E (BPE), and bisphenol B (BPB). While absolute recoveries of the method were improved for water and some beverage products (e.g. diet cola, iced tea), breakthrough may also have occurred during SPE of 200 mL of other beverages (e.g. BPF in cola). Improvements in method detection limits were observed with the analysis of large sample volumes for all bisphenols at ppt (pg/g) to sub-ppt levels. This improvement was found to be proportional to sample volumes for water and beverage products with less interferences and noise levels around the analytes. Matrix effects and interferences were observed during SPE of larger volumes (100 and 200 mL) of the beverage products, and affected the accurate analysis of BPF. This improved method was used to analyse bisphenols in various beverage samples, and only BPA was detected, with levels ranging from 0.022 to 0.030 ng/g for products in PET bottles, and 0.085 to 0.32 ng/g for products in cans.
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Compuestos de Bencidrilo/análisis , Bebidas/análisis , Agua Potable/química , Fenoles/análisis , Extracción en Fase Sólida , Cromatografía de Gases y Espectrometría de MasasRESUMEN
Experimental and/or epidemiological studies suggest that prenatal exposure to bisphenol A (BPA) may delay fetal lung development and maturation and increase the susceptibility to childhood respiratory disease. However, the underlying mechanisms remain to be elucidated. In our previous study with cultured human fetal lung fibroblasts (HFLF), we demonstrated that 24-h exposure to 1 and 100 µM BPA increased GPR30 protein in the nuclear fraction. Exposure to 100 µM BPA had no effects on cell viability, but increased cytoplasmic expression of ERß and release of GDF-15, as well as decreased release of IL-6, ET-1, and IP-10 through suppression of NFκB phosphorylation. By performing global gene expression and pathway analysis in this study, we identified molecular pathways, gene networks, and key molecules that were affected by 100, but not 0.01 and 1 µM BPA in HFLF. Using multiple genomic and proteomic tools, we confirmed these changes at both gene and protein levels. Our data suggest that 100 µM BPA increased CYP1B1 and HSD17B14 gene and protein expression and release of endogenous estradiol, which was associated with increased ROS production and DNA double-strand breaks, upregulation of genes and/or proteins in steroid synthesis and metabolism, and activation of Nrf2-regulated stress response pathways. In addition, BPA activated ATM-p53 signaling pathway, resulting in increased cell cycle arrest at G1 phase, senescence and autophagy, and decreased cell proliferation in HFLF. The results suggest that prenatal exposure to BPA at certain concentrations may affect fetal lung development and maturation, and thereby affecting susceptibility to childhood respiratory diseases.
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17-Hidroxiesteroide Deshidrogenasas/genética , Contaminantes Ocupacionales del Aire/toxicidad , Compuestos de Bencidrilo/toxicidad , Citocromo P-450 CYP1B1/genética , Estradiol/metabolismo , Pulmón/efectos de los fármacos , Factor 2 Relacionado con NF-E2/metabolismo , Fenoles/toxicidad , Proteína p53 Supresora de Tumor/metabolismo , 17-Hidroxiesteroide Deshidrogenasas/metabolismo , Autofagia , Puntos de Control del Ciclo Celular , Senescencia Celular/efectos de los fármacos , Citocromo P-450 CYP1B1/metabolismo , Fibroblastos/efectos de los fármacos , Humanos , Especies Reactivas de Oxígeno/metabolismo , Regulación hacia ArribaRESUMEN
Bisphenol A (BPA) has been shown to exert biological effects through estrogen receptor (ER)-dependent and ER-independent mechanisms. Recent studies suggest that prenatal exposure to BPA may increase the risk of childhood asthma. To investigate the underlying mechanisms in the actions of BPA, human fetal lung fibroblasts (hFLFs) were exposed to varying doses of BPA in culture for 24hr. Effects of BPA on localization and uptake of BPA, cell viability, release of immune and developmental modulators, cellular localization and expression of ERα, ERß and G-protein coupled estrogen receptor 30 (GPR30), and effects of ERs antagonists on BPA-induced changes in endothelin-1 (ET-1) release were examined. BPA at 0.01-100µmol/L caused no changes in cell viability after 24hr of exposure. hFLFs expresses all three ERs. BPA had no effects on either cellular distribution or protein expression of ERα, however, at 100µmol/L (or 23µmol/L intracellular BPA) increased ERß protein levels in the cytoplasmic fractions and GPR30 protein levels in the nuclear fractions. These paralleled with increased release of growth differentiation factor-15, decreased phosphorylation of nuclear factor kappa B p65 at serine 536, and decreased release of ET-1, interleukin-6, and interferon gamma-induced protein 10. ERs antagonists had no effects on BPA-induced decrease in ET-1 release. These data suggest that BPA at 100µmol/L altered the release of immune and developmental modulators in hFLFs, which may negatively influence fetal lung development, maturation, and susceptibility to environmental stressors, although the role of BPA in childhood asthma remains to be confirmed in in vivo studies.
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Compuestos de Bencidrilo/toxicidad , Estrógenos no Esteroides/toxicidad , Fenoles/toxicidad , Línea Celular , Disruptores Endocrinos/toxicidad , Fibroblastos , Humanos , Interleucina-6/metabolismo , Receptores de Estrógenos/metabolismoRESUMEN
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.