Unintentionally produced dioxin-like polychlorinated biphenyls during cooking

Concentration and risk assessment of PCNs in green tea in different locations in China

Polychlorinated naphthalenes (PCNs) were added to the Stockholm Convention list of persistent organic pollutants in 2015. PCNs are mainly unintentionally produced during industrial processes nowadays, and can be widely found in environmental media and foodstuffs. Dietary intake is the primary pathway for human exposure to PCNs. PCNs in different categories of foodstuffs have been reported. However, little information on PCN concentrations in green tea, a popular beverage worldwide is available. In this study, all 75 PCN congener concentrations and distributions in green tea samples (n = 102) from 11 regions in China were determined, and risk assessment of human exposure to PCNs through tea consumption was conducted. The PCN concentrations in all the green tea samples were 3.62-175 pg/g dry weight (mean 36.1 pg/g dry weight). Similar PCN homolog and congener profiles were found in green tea samples from different areas. The dominant PCN homologs in all of the green tea samples were di-CNs, tetra-CNs, and tri-CNs. No direct relationships were found between PCN emission sources and PCN concentrations in the green tea samples. The brewing technique could affect the PCN concentrations and homolog profiles in tea leaves. PCNs in green tea from China were found to pose little risk to humans.

Emerging investigator series: the role of chemical properties in human exposure to environmental chemicals

One of the ultimate goals of environmental exposure science is to mechanistically understand how chemical properties and human behavior interactively determine human exposure to the wide spectrum of chemicals present in the environment. This comprehensive review assembles state-of-the-art knowledge of the role of partitioning, dissociation, mass transfer, and reactive properties in human contact with and absorption of organic chemicals via oral, dermal, and respiratory routes. Existing studies have revealed that chemicals with different properties vary greatly in mass distribution and occurrence among multiple exposure media, resulting in distinct patterns of human intake from the environment. On the other hand, these chemicals encounter different levels of resistance in the passage of intestinal, dermal, and pulmonary absorption barriers and demonstrate different levels of bioavailability, due to the selectivity of biochemical, anatomical and physiological structures of these absorption barriers. Moving forward, the research community needs to gain more in-depth mechanistic insights into the complex processes in human exposure, advance the technique to better characterize and predict chemical properties, generate and leverage experimental data for a more diverse range of chemicals, and describe better the interactions between chemical properties and human behavior.

Use of sucralose in foods heated during manufacturing does not pose a risk to human health

Regulatory agencies around the world have found sucralose to be a safe ingredient for use in food. A recent review by the German Federal Institute for Risk Assessment (BfR) hypothesized that sucralose use in foods heated during their manufacture might pose a health risk, by resulting in the formation of certain chlorinated compounds; specifically, polychlorinated dibenzodioxins (PCDDs), polychlorinateddibenzofurans (PCDFs) and/or free or bound 3-monochloropropanediol (3-MCPD), some of which are considered potential carcinogens. The BfR further encouraged the European Food Safety Authority (EFSA), which is in the process of conducting a staged re-evaluation of a range of food additives, including sucralose, to specifically address their hypothesis. This paper reports the results of new studies requested by EFSA to analyze for the presence of PCDDs, PCDFs and 3-MCPDs in a range of foods. As requested, foods were prepared with typical sucralose use levels and thermally processed under typical food processing conditions. The presence of the compounds of interest were analyzed using validated and accepted analytical methods (e.g. US Environmental Protection Agency (EPA); American Oil Chemists Society (AOCS)). The results of these new analytical studies show no evidence for the formation of these compounds due to sucralose presence. This paper also reports a critical analysis of the studies cited in the BfR review as the basis for its hypothesis. This analysis shows that the cited studies do not represent food manufacturing conditions and are thus not reliable for predicting the fate of sucralose in foods. This work reaffirms that sucralose is safe for use in food manufacture, including when heating is required.

Modified Camellia oleifera Shell Carbon with Enhanced Performance for the Adsorption of Cooking Fumes

Using Camellia oleifera shell (COS) as a raw material and phosphoric acid as the activator, activated Camellia oleifera shell carbon (COSC-0) was prepared and then modified by Fenton’s reagent (named as COSC-1). SEM, GC-MS, FTIR, and specific surface area and pore analyzers were used to study the adsorption performance of COS, COSC-0, and COSC-1 on cooking fumes. Results showed that COSC-1 was the best adsorbent compared with COS and COSC-0. The adsorption quantity and penetrating time of COSC-1 were 44.04 mg/g and 4.1 h, respectively. Most aldehydes could be adsorbed by COSC-1, which was due to the large number of carbonyl and carboxyl groups generated on the surface of COSC-1 from the action of Fenton’s reagent. The adsorption effect of COSC-1 on different types of pollutants in cooking fumes was analyzed based on the similar compatibility principle. COSC-1 showed a much higher adsorption effect on the strong polarity functional groups than on weak polar groups. The results provide a theoretical basis for the application of Camellia oleifera shell carbon adsorption technology in the treatment of cooking fumes.

The technology of curd cake with sucralose: a infrared spectroscopy analysis

The article presents the results of developing technology for the production of curd cake using a low-calorie sweetener sucralose. The implementation of this direction in the form of a partial replacement in the sugar formulation for effective sweeteners sucralose is proposed. As a prototype, a sugar-based recipe was used, in which a partial replacement (at the level of 50%) of sugar with sucrose was carried out. Sucralose was formulated as the commercial sweetener TM Splenda, which contains maltodextrin and sucralose. All samples, including the control on sugar, were subjected to organoleptic evaluation, which showed the absence of extraneous flavors in all samples and their similarity in terms of sweetness compared to control. IR spectra of the sweetener, curd cake with sugar, as well as curd cakes with 50% and 100% sugar substitution for sweetener were obtained and analyzed. The analysis showed the presence of identical characteristic bands on the spectra of the sweetener and samples of sucralose cakes, which suggests that the sweetener TM Splenda does not undergo thermal degradation when baking curd cake. However, the literature analysis indicates the danger of the formation of toxic gaseous substances that are obtained during the thermal treatment of products with sucralose.

Organochlorine Pesticides and PCBs in Traditionally and Industrially Smoked Pork Meat Products from Bosnia and Herzegovina

The aim of this study was to determine the concentration of 19 organochlorine pesticides (OCPs): (hexachlorocyclohexane (α-HCH, β-HCH, δ-HCH), lindane, aldrin, heptachlor, heptachlor epoxide, trans-chlordane, cis-chlordane, endosulfane I, endosulfane II, endosulfane sulfate, dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), dieldrin, endrin, dichlorodiphenyldichloroethane (DDD), methoxychlor and endrin ketone and 6 polychlorinated biphenyls (PCBs) (PCB 28, PCB 52, PCB 101, PCB 153, PCB 138 and PCB 180). The samples were taken from pancetta, dry pork neck (budiola), pork tenderloin and sausages produced in Rakitno (Bosnia and Herzegovina), smoked in both a traditional smokehouse and in an industrial chamber. Instrumental analysis was performed using gas chromatography-mass spectrometry (GC-MS). The reliability of the results, i.e., quality control is ensured by standard laboratory practice, which involves participation in proficiency test, the use of blank samples, reference materials and implementation of recommendations given by the relevant international organizations. The concentrations of α-HCH, lindane, PCB 28, PCB 52 and PCB 153 were detected and quantified. The concentrations of OCPs and PCBs did not significantly vary depending on product type and the conditions of production. All the examined samples were for human consumption.

Toxic emissions resulting from sucralose added to electronic cigarette liquids

Electronic cigarettes (ECIGs) are appealing in part because of the many flavors of the liquids used in them. Concerns have been raised that some ECIG liquid flavors, especially those that are sweet, are attracting otherwise nicotine-naïve youth to ECIGs. Sucralose is an artificial, non-caloric sweetener that is added to some ECIG liquids. In this study, we evaluated the toxicants, namely isomers of chloropropanols that can be produced when sucralose-containing ECIG liquid is aerosolized. An analytical separation method relying on solid-phase extraction (SPE) to isolate chloropropanols from the propylene glycol/glycerol matrix was developed. Chloropropanols were then derivatized by silylation before they were analyzed on GC-MS. The influence of different ECIG operating conditions on the generation of chloropropanols was studied by varying ECIG device design and power output and also the sucralose concentration of the liquid. Heated sucralose-containing ECIG liquids produce two toxic compounds that can be found in the resulting aerosols. The two chloropropanols, 3-monochloro-1,2-propanediol (3-MCPD) and 1,3-dichloropropanol (1,3-DCP) that were detected under all conditions were found to be correlated significantly with liquid sucralose content. Effective regulation of ECIGs will minimize user and bystander exposure to these and other ECIG toxicants.

Elimination of short-chain chlorinated paraffins in diet after Chinese traditional cooking-a cooking case study

Short-chain chlorinated paraffins (SCCPs) were listed in the Stockholm Convention in 2017 yet are still used in large-tonnage in China. Diet is the main external exposure pathway of many persistent organic pollutants (POPs), but SCCP diet exposure has not been studied completely thus far. In this study, samples of 122 raw foods were collected from markets in Beijing, cooked with Chinese traditional cooking methods, and analyzed for SCCPs. Overall, SCCP levels in the raw food materials ranged from0.67 to 5100 ng g^-1 wet weight (ww). SCCP elimination was found in six out of seven kinds in the cooking case study. Concentrations in the raw food used for cooking ranged from 3.6 to 52 ng g^-1 ww, while the corresponding values in the cooked food ranged from 0.67 to 10.8 ng g^-1 ww. The SCCP elimination rate ranged from 12% to 93%. The daily average intake of SCCPs for the general population through raw food and cooked food was assessed. The total daily SCCP intake via these foods was 403 and 145 ng kg^-1 bw d^-1, which suggests that different assessing approaches may result in different estimated SCCP diet exposure amounts.

Levels, congener profile and inventory of polychlorinated biphenyls in sediment from the Songhua River in the vicinity of cement plant, China: a case study

This study investigated the contamination levels, homologue, and congener profiles and evaluated the residue inventory of polychlorinated biphenyls (PCBs) in sediment of the Songhua River in the vicinity of cement plant. The total concentration of detected 35 PCB congeners ranged from 1.12 to 2.19 ng/g dry weight (dw) in sediment, with a mean value of 1.56 ng/g dw, and the concentration of PCBs decreased in the following order: the downstream > cement plant > upstream. The results of total organic carbon (TOC)-normalized PCB concentrations indicate that the sediments have low potential ecological risk in this area. The study results on homologue and congener of PCBs show that the emissions from cement production could be the major sources of PCBs in sediment, and the low-chlorinated PCBs will be exchanged among air, water, and sediment with increasing temperature during summer and flow to downstream with water during the wet season. The spatial density and total burden of PCBs in the surface sediments were 17.2 ng/cm(2) and 1.2 kg, respectively. To our knowledge, this study is the first to explore the pollution characteristics of unintentionally produced PCB emissions from cement industry by means of monitoring sediment samples.

Spatial-temporal variation, possible source and ecological risk of PCBs in sediments from Songhua River, China: Effects of PCB elimination policy and reverse management framework

The spatial variation, possible sources and ecological risk of polychlorinated biphenyls (PCBs) in the sediment from the Songhua River, China were investigated and evaluated in this paper. The total concentration of PCBs ranged from 0.59 to 12.38ng/gdw, with a mean value of 3.82ng/gdw. The seven indicators of PCB concentrations are significantly correlated with the total PCB concentrations (R=0.950, p=0.000). The temporal trend of PCBs in sediments showed that the total PCBs in the Songhua River have decreased since 2008. Point source pollution, discharge of historical usage and industrial sewage, and emissions of unintentionally produced PCBs were the predominant sources in sediment. A risk assessment indicated that most of the sampling sites in the sediment were at low potential ecological risk. The apparent decrease of PCBs in the sediment appeared after the China National Coordination Group for Implementation of the Stockholm Convention was established. A conceptual reverse management framework for PCBs and other organic pollutants was established in this study.

Progressive risk assessment of polychlorinated biphenyls through a Total Diet Study in the Korean population

Human exposure to polychlorinated biphenyls (PCBs) from foods was investigated through a Total Diet Study (TDS) for the first time in Korea. A representative food list was developed from food intake data. Non-selected foods were also included in the TDS through the mapping process to anticipate practical risk assessment. For better representativeness, data (2008-2011) from the Korea National Health and Nutrition Examination Survey (KNHANES) were combined with the TDS data set. And also, we estimated the dietary exposure to PCBs from various food items using a 'best-fit' mapping process and assessed the differences in PCB exposures by sex and age. In this study, we examined total PCBs (62 congeners) including dioxin-like PCBs (DL-PCBs) and indicator PCBs, which are congeners that are mainly detected in various environmental matrices. The average dietary exposure (3.94 ng/kg body weight/day) that was estimated through food intake was 19.7% of the World Health Organization (WHO) recommendation.

Fate of PBDEs during food processing: Assessment of formation of mixed chlorinated/brominated diphenyl ethers and brominated dioxins/furans

The aim of this study was to evaluate effects of food processing on PBDE levels, in particular influence of heat treatment on degradation of PBDEs, including possible formation of chlorinated diphenyl ethers or brominated dioxins/furans as degradation products. It was shown that PBDEs heated in the presence of chlorine (from either organic or inorganic sources) formed mixed chlorinated/brominated diphenyl ethers. However, no PCDEs were formed in the presence of lipids. Lipid medium increased stability of PBDEs exposed to UV irradiation. Profile of congeners formed in result of the debromination reaction was significantly different than profiles observed by some other authors in aliphatic organic solvents. Grilling processes increased concentrations (calculated on the fresh product basis) of the studied compounds by 4-8/22-34% for electric/coal grill, respectively. Depending on the congener and on the applied heat treatment, PBDE mass in pork meat after grilling dropped by 26-53%. No detectable quantities of either brominated dioxins or furans were formed during thermal processing of food containing typical levels of PBDEs.

Thermal degradation of sucralose: a combination of analytical methods to determine stability and chlorinated byproducts

In the late years, much attention has been brought to the scientific community regarding the safety of sucralose and its industrial applications. Although it is the most used artificial sweetener in foods and pharmaceuticals, many questions still arise on its potential to form chlorinated byproducts in high temperatures, as demonstrated by several recent studies. In the present contribution, we use a combination of differential scanning calorimetry and thermogravimetric analysis coupled with infrared spectroscopy (DSC/TGA/IR), Hot-stage microscopy (HSM) and high-resolution mass spectrometry (HRMS) on samples submitted to water bath at mild temperatures to evaluate a broad spectrum of hazardous compounds formed in the degradation of this product. TGA/IR has revealed that there is effective decomposition in form of CO₂ along with the formation of hydrogen chloride and other minor compounds. HSM results have provided accurate information, where the melting of the crystals was observed, followed by decomposition. Chlorinated derivatives, including polychlorinated aromatic hydrocarbons (PCAHs) were also confirmed by HRMS. These findings not only corroborate the suspected instability of sucralose to high temperatures, but also indicate that even exposed to mild conditions the formation of hazardous polychlorinated compounds is observed.

Polychlorinated dibenzo-p-dioxins and dibenzofurans formed from sucralose at high temperatures

Sucralose is a widely-used artificial high-intensity sweetener. Although doubts have been raised about the safety of sucralose by several researchers, it can still be found in a broad range of foods and beverages worldwide, including in baked goods. Sucralose may decompose at high temperatures, and participate in chlorination reactions, generating highly toxic compounds. Here, we demonstrate that heating sucralose at high temperatures in stainless steel or other metal utensils in the presence of rust (Al₂O₃, Fe₂O₃, and CuO) produces polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). PCDD/Fs were found in smoke generated during the heating of sucralose and in the residues after heating. CuO enhanced the PCDD/F yield in comparison with Al₂O₃ and Fe₂O₃.

Fate of polybrominated diphenyl ethers during cooking of fish in a new model cooking apparatus and a household microwave

Fish is a major source of human exposure to polybrominated diphenyl ethers (PBDEs). Because fish is mainly consumed after cooking, this measure may alter the pattern and amounts of PBDEs that are finally consumed. To investigate this issue, we developed a model cooking apparatus consisting of a small glass bowl and a beaker glass with an exhaust fitted with a polyurethane foam filter connected to a water jet pump. In this model cooking apparatus, fish (1 g) and/or sunflower oil (0.2/0.4 g) spiked with three PBDE congeners was cooked for 30 min. Small amounts of the semi-volatile PBDEs were evaporated from the fish (BDE-47 < BDE-15), while the non-volatile BDE-209 was partly transformed. Additional experiments in a household microwave provided similar results, except that no transformation was observed for BDE-209. The model cooking apparatus proved to be well-suited to study the fate of polyhalogenated compounds in fish during cooking.

Sucralose, a synthetic organochlorine sweetener: overview of biological issues

Sucralose is a synthetic organochlorine sweetener (OC) that is a common ingredient in the world's food supply. Sucralose interacts with chemosensors in the alimentary tract that play a role in sweet taste sensation and hormone secretion. In rats, sucralose ingestion was shown to increase the expression of the efflux transporter P-glycoprotein (P-gp) and two cytochrome P-450 (CYP) isozymes in the intestine. P-gp and CYP are key components of the presystemic detoxification system involved in first-pass drug metabolism. The effect of sucralose on first-pass drug metabolism in humans, however, has not yet been determined. In rats, sucralose alters the microbial composition in the gastrointestinal tract (GIT), with relatively greater reduction in beneficial bacteria. Although early studies asserted that sucralose passes through the GIT unchanged, subsequent analysis suggested that some of the ingested sweetener is metabolized in the GIT, as indicated by multiple peaks found in thin-layer radiochromatographic profiles of methanolic fecal extracts after oral sucralose administration. The identity and safety profile of these putative sucralose metabolites are not known at this time. Sucralose and one of its hydrolysis products were found to be mutagenic at elevated concentrations in several testing methods. Cooking with sucralose at high temperatures was reported to generate chloropropanols, a potentially toxic class of compounds. Both human and rodent studies demonstrated that sucralose may alter glucose, insulin, and glucagon-like peptide 1 (GLP-1) levels. Taken together, these findings indicate that sucralose is not a biologically inert compound.