Exposure estimates of phthalates and DINCH from foods and personal care products in comparison with biomonitoring data in 24-hour urine from the Norwegian EuroMix biomonitoring study.

Phthalates are diesters of phthalic acid and have been widely used as plasticizers in polyvinyl chloride (PVC) plastics. Phthalates are also used as excipients in pharmaceuticals and personal care products (PCPs). Phthalates can migrate from the plastic into the air, water and food, and humans can be exposed via multiple pathways such as dermal, oral and inhalation. There is evidence that phthalates can induce reproductive and developmental toxicity not only in experimental animals but also in humans through disruption of estrogenic activity. The aim of this study was to collect concentration data on five phthalates in foods and PCPs from the scientific literature and combine these with food consumption data and PCP use frequency data from the EuroMix biomonitoring (BM) study in order to assess exposure. Probabilistic exposure assessments of phthalates were performed from foods and PCPs. Due to the very limited data available in the literature for DINCH, an exposure assessment was not carried out for this compound. The food groups with the highest contribution to phthalates exposure were: beverages, dairy, bread and meat products. The exposure estimates were compared with the measured phthalate metabolite levels from 24-hour urine samples. Regarding the oral route, measured phthalate exposure was between the lower bound (LB) and medium bound (MB) estimated exposure for all phthalates, except for DEP. The measured exposure from urine correlated with the estimated exposure from food for DEHP and DBP, while for BBP and DEP it correlated with the exposure estimates from PCPs. There were no significant differences between the BM data and the estimated exposure, except for DINP for males (p = 0.01). The LB and MB phthalate exposures estimated from foods and PCPs and the measured exposure from the urine were considerably lower than their respective tolerable daily intake (TDI) values established by the European Food Safety Authority (EFSA) and the World Health Organization (WHO). For the upper bound (UB), the exposure estimates are approximately double the TDI; however, this is regarded as a worst-case estimate and has low correlation with the measured exposure.

Per- and polyfluoroalkyl substances in serum and associations with food consumption and use of personal care products in the Norwegian biomonitoring study from the EU project EuroMix.

BACKGROUND: Human exposure to chemicals through the oral, dermal, or inhalation routes is significant. To assess this exposure, a human biomonitoring study was conducted in Norway to examine the plausibility of source-to-dose calculations for chemical mixtures. Per- and polyfluoroalkyl substances (PFASs) are man-made compounds used for their surfactant properties, and several are persistent and bioaccumulative. Some PFASs are toxic and are regarded as endocrine disruptors and have been shown to suppress immune function and affect cholesterol homeostasis. Using the participants from the EuroMix BM study, we set out to describe PFAS concentrations and to evaluate associations with diet and use of personal care products (PCPs). METHODS: Participants (44 males and 100 females) kept detailed diaries on their food consumption and their PCP use for two non-consecutive days. All urine (24 h) and blood samples were collected at the end of each study day. Levels of 25 PFASs were analysed in serum from study day 1 using a high throughput online solid phase extraction ultra-high-performance liquid chromatography tandem mass spectrometry method. Multivariable linear regressions were performed between each food and PCP category and each chemical and were sex-stratified when the consumption of food or use of PCPs was significantly different between men and women. RESULTS: Eight PFASs were detected in all analysed samples (PFHxS, PFHpS, PFOS, PFOA, PFNA, PFDA, PFUnDA and PFDoDA), and four PFASs were below the limit of detection (PFOPA, PFDPA, PFHxA, and EtFOSA). Several PFASs were found to be positively associated with fish consumption (PFOS, PFNA, PFUnDA, PFDoDA, PFDA, PFDS and PFTrDA). Sunscreen, mouthwash, and lip gloss/lip balm were found to be positively associated with PFASs (PFOA, PFTrDA, and PFOSA). CONCLUSION: The participants in the EuroMix study were exposed to PFASs through their diet and PCP use. Several foods and PCPs were found to be potential sources of exposure to PFASs.

The Norwegian biomonitoring study from the EU project EuroMix: Levels of phenols and phthalates in 24-hour urine samples and exposure sources from food and personal care products.

BACKGROUND: Exposure to multiple chemicals occurs daily through several routes; diet, inhalation and dermal contact. Real-life exposure assessment is needed to understand the risk. Therefore, a human biomonitoring (BM) study was performed to examine the plausibility of source-to-dose calculations for chemical mixtures in the Horizon 2020 EuroMix project. OBJECTIVES: To provide a detailed description of the design of the EuroMix BM study, and to present the initial results for urinary phenols and phthalates and to describe their exposure determinants from foods and personal care products (PCPs). METHOD: Adults (44 males and 100 females) kept detailed diaries on their food consumption, PCP use and handling of cash receipts. Urine samples were collected over the same 24-hour period. Urinary levels of four parabens, five bisphenols, oxybenzone/benzophenone-3 (OXBE), triclosan (TCS), triclocarban (TCC) and metabolites of eight phthalates and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) were analysed by ultra-high-performance liquid chromatography and tandem mass spectrometry. Multivariable linear regressions were performed between PCPs/food categories and each dependent chemical variable separately, and were only sex-stratified when an interactions between sex and the independent variable was significant. RESULTS: The detection rate for the metabolites of phthalates and DINCH, and bisphenol A (BPA) and TCS in urine was 88-100%, while bisphenol S (BPS) and bisphenol F (BPF) were only found in 29% and 4% of the urine samples, respectively. Bisphenol B (BPB), bisphenol AF (BPAF) and TCC were not detected. Food groups associated with phenol exposure were meat, bread, beverages and butter and oil. Food determinants for phthalate exposure were sweets, butter and oil, fruit and berries and other foods. The only positive association between the use of PCPs and phenols was found between BPA and lip gloss/balm. Phthalate exposure was associated with the use of shower gel, hand cream (females), toothpaste, anti-wrinkle cream (females) and shaving products (males). CONCLUSION: The participants in the EuroMix BM study were exposed to a mixture of phenols and phthalates. A variety of food categories and PCPs were found to be possible sources of these chemicals. This indicates a complex pattern of exposure to numerous chemicals from multiple sources, depending on individual diet and PCP preferences.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces genetic changes in murine intestinal tumours and cells with ApcMin mutation.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is one of the mutagenic heterocyclic amines derived from cooked meat. In previous animal studies, spontaneous tumour formation in B6(Min/+) mice was associated with somatic loss of the wild-type Apc+ allele by loss of the entire chromosome 18 or by recombination. The objective of this study was to examine genetic changes caused by PhIP-exposure in a mouse intestinal cell line and in tumours from hybrid mice by keeping track of the chromosomes carrying the two Apc alleles. We transformed the SV40 T-immortalised intestinal epithelial cell line IMCE, derived from the B6(Min/+) mice by exposure to N-OH-PhIP, and studied the effect on Apc status and chromosome 18. Eighteen transformed cultures were obtained and all of them had retained the Apc+ allele. Five of seven transformed cultures were tumorigenic after implantation in nude mice. Chromosomal analysis of these five cultures and the parent IMCE cell line showed that the IMCE cells were near-tetraploid with an average of 77 chromosomes/cell, while the tumorigenic cell cultures were all triploid to hyper-triploid with a range of 61-69 chromosomes/cell. The number of copies of chromosome 18 was about four in the IMCE line and this copy number was retained in the transformed lines derived from IMCE. Changes in chromosome 18 and Apc during tumour development in vivo were examined in spontaneously formed and PhIP-induced intestinal tumours from two hybrid mice strains, i.e. B6(Min/+) - a murine FAP model - crossed with either AKR/J or A/J. We evaluated the allelic status of Apc, and the heterogenic microsatellite markers D18Mit19 and D18Mit4, located at the upper and lower ends of chromosome 18, respectively. In tumours from untreated animals, instability in the D18Mit19 and Apc was observed. Upon PhIP exposure, the B6(Min/A+) hybrid mouse tumours differed distinctly in genetic profile from those obtained from untreated animals and we detected three genetically different tumour groups, all of which had apparently retained Apc+. One group had allelic balance between the Apc(Min) and Apc+, the second had allelic imbalance between the Apc and D18Mit4 alleles, indicative of chromosomal stability in the first group and instability in the lower end of chromosome 18 in the second group, respectively. The third group showed variable allelic status of the three markers. A similar change in genetic profile was also seen in intestinal tumours of PhIP-exposed B6(Min/AKR+) hybrid mice, but it was less pronounced. Chromosomal breaks and/or recombinational events could be alternative explanations for the observed allelic imbalances in chromosome 18 markers in intestinal tumours from PhIP-exposed mice.

Accumulation of metallothionein and its multiple forms by zinc, cadmium and dexamethasone in human peripheral T and B lymphocytes and monocytes.

Metallothionein (MT) is produced at high rates in isolated monocytes, and T and B lymphocytes during induction in vitro. At optimal concentrations, 125 microM for Zn and 10 microM for Cd and dexamethasone (dex), MT was demonstrated after only 2 h in some cases, and in all cell types substantial levels were measured after 1 day of exposure to all three inductors. With Cd, lower amounts of MT were found, but maximum levels were reached faster than with Zn. The same result was found for dex compared to Zn. Zn and dex in combination showed the same accumulation rate as Zn alone. If the inductors were used in lower concentrations than optimal, reduced accumulation rates occurred, particularly during the first part of the exposure period. No MT was found for concentrations below 5 microM Zn, 1 microM Cd or 0.5 microM dex. The constitutive levels of MT (mean +/- S.E.M.) were 0.11 +/- 0.05, 0.54 +/- 0.3, 0.06 +/- 0.05 and 0.15 +/- 0.08 nmol Cd bound/5 x 10(6) unseparated mononuclear cells (MNC), monocytes, T lymphocytes and B lymphocytes, respectively. Monocytes accumulated 19 times and B lymphocytes 6 times more MT than T lymphocytes after 2 days of exposure to 125 microM Zn. Despite these differences in accumulated amounts of MT, the fold accumulation values were rather similar between the cell types, reflecting corresponding variations in background MT levels. After exposure of unseparated MNC to 125 microM Zn for 2 days, removal of the metal caused constitutive MT levels to be reestablished in 5 days. Five different MT forms, all capable of Cd complexation, were demonstrated in these cells. These forms had kinetically different behaviour during Zn exposure among the cell types, and the response to Cd was different from the Zn response. The results indicate metals to be closely controlled in MNC and emphasize a role for multiple MT forms in the process of regulation.

Mitogenicity and metallothionein induction: two separate effects of zinc ions on human mononuclear blood cells.

The mitogenic effect of elevated concentrations of zinc ions on human lymphocytes was found to be inhibited by the glucocorticoid hormone dexamethasone. The effect decreased progressively from complete block to partial inhibition when the culture period before the addition of dexamethasone was prolonged. In contrast, dexamethasone did not inhibit an induced formation of metallothionein in mononuclear cells. Furthermore, dexamethasone itself was found to induce small amounts of metallothionein. Apparently, the mitogenic effect and the induction of metallothionein by zinc ions in mononuclear cells occur by mutually independent mechanisms.

Effect of the metal in the reaction between metallothionein and antimetallothionein antibody.

1. An antimetallothionein antibody, raised against Cd-carrying metallothionein, was applied in Western blotting of metallothionein. 2. Treatment of the electroblotted nitrocellulose sheets with metals belonging to the periodic system transition groups Ib and IIb, or with Pb, Ni or Cr, considerably enhanced binding of anti-metallothionein. A similar effect was found when the electroblotted sheets were treated with the strong alkylator N-ethylmaleimide. 3. It seems that the binding of metal to metallothionein modifies the configuration of the antibody binding sites by the formation of metal thiolate complexes. 4. Metal treatment of the nitrocellulose sheets after electroblotting, but before application of the primary antibody, offers a convenient method for use in Western blotting to significantly potentiate the reaction between metallothionein and the antimetallothionein antibody.

Induction of metallothionein production by zinc in human mononuclear cells.

1. Low mol. wt proteins with high Cd-binding capacity were found to be induced by Zn in cultured monocytes and lymphocytes. 2. In T cell cultures one protein was found to be induced by 125 microM Zn for 6 days, while in monocytes and B enriched cells under these conditions two proteins were found, of which the one with higher mol. wt had similar electrophoretic mobility to the T cell protein on polyacrylamide gels. 3. Mol. wt criteria and crossreactivity towards anti-metallothionein (Mt) antibody identified these proteins to be Mts of about 23 and 27 kDa mol. wt. 4. Metal binding studies indicated that monocyte and lymphocyte Mts had a higher affinity to Zn compared to Cd than rat liver Mt and Mts from Cd-resistant substrains of a human epithelial and a murine fibroblast cell line. 5. The presence of the T cell mitogen phytohemagglutinin (PHA) was found not to be necessary for this Mt induction by Zn.