Potential emerging chemical risks in the food chain associated with substances registered under REACH.

A screening procedure for the identification of potential emerging chemical risks in the food and feed chain developed in a previous EFSA-sponsored pilot study was applied to 15021 substances registered under the REACH Regulation at the time of evaluation. Eligible substances were selected from this dataset by excluding (a) intermediates handled under strictly controlled conditions, (b) substances lacking crucial input data and (c) compounds considered to be outside the applicability domain of the models used. Selection of eligible substances resulted in a considerable reduction to 2336 substances. These substances were assessed and scored for environmental release (tonnage and use information from REACH registration dossiers), biodegradation (predictions from BIOWIN models 3, 5 and 6 evaluated in a battery approach), bioaccumulation in food/feed (ACC-HUMANsteady modelling) and chronic human health hazards (classification according to the CLP Regulation for carcinogenicity, mutagenicity, reproductive toxicity and repeated dose toxicity as well as IARC classification for carcinogenicity). Prioritisation based on the scores assigned and additional data curation steps identified 212 substances that are considered potential emerging risks in the food chain. Overall, 53% of these substances were prioritised due to chronic hazards identified in REACH registrations dossiers only (i.e. hazards not identified in classifications from other sources). Bioaccumulation in food and feed predicted on the basis of ACC-HUMANsteady modelling identified many substances that are not considered bioaccumulative in aquatic or terrestrial organisms based on screening criteria of the relevant ECHA guidance documents. Furthermore, 52% of the priority substances have not yet been assessed for their presence in food/feed by EU regulatory agencies. This finding and illustrative examples suggest that the screening procedure identified substances that have the potential to be emerging chemical risks in the food chain. Future research should investigate whether they actually represent emerging chemical risks as defined in EFSA's mandate.

Development of a novel scoring system for identifying emerging chemical risks in the food chain.

The European Food Safety Authority (EFSA) is responsible for risk assessment of all aspects of food safety, including the establishment of procedures aimed at the identification of emerging risks to food safety. Here, a scoring system was developed for identifying chemicals registered under the European REACH Regulation that could be of potential concern in the food chain using the following parameters: (i) environmental release based on maximum aggregated tonnages and environmental release categories; (ii) biodegradation in the environment; (iii) bioaccumulation and in vivo and in vitro toxicity. The screening approach was tested on 100 data-rich chemicals registered under the REACH Regulation at aggregated volumes of at least 1000 tonnes per annum. The results show that substance-specific data generated under the REACH Regulation can be used to identify potential emerging risks in the food chain. After application of the screening procedure, priority chemicals can be identified as potentially emerging risk chemicals through the integration of exposure, environmental fate and toxicity. The default approach is to generate a single total score for each substance using a predefined weighting scenario. However, it is also possible to use a pivot table approach to combine the individual scores in different ways that reflect user-defined priorities, which enables a very flexible, iterative definition of screening criteria. Possible applications of the approaches are discussed using illustrative examples. Either approach can then be followed by in-depth evaluation of priority substances to ensure the identification of substances that present a real emerging chemical risk in the food chain.

[Assessment of breast feeding rates during compulsory vaccination: preliminary outcomes]. / Rilevazione dei tassi di allattamento al seno al momento delle vaccinazioni obbligatorie: dati preliminari.

AIM: In consideration of the World Health Organization (WHO) recommendations on promoting and supporting breast feeding, a measurement of breast feeding rates was planned within Vercelli's Province (ASL 11, Piedmont, Italy) in order to compare the local situation to the national and international one, and to promote ideas and strategies for increasing the practice of breast feeding up to six months or beyond. METHODS: During Diptheria Tetanus whole cell Pertussis vaccination (DTP) vaccination a questionnaire about their children's feeding was handed out to all mothers. Preliminary outcomes were elaborated after a follow-up of six months. RESULTS: So far 1591 questionnaires have been collected. During the first DTP immunizations 31.63% of the children were exclusively breastfed and 15.81% were partially breastfed. At the second vaccination, 11.14% and 37.68% of infants were completely and partially breastfed, respectively. A 36.11% of partially breast feeding still emerged during the third DTP vaccination. CONCLUSIONS: The outcomes of this study are inferior compared to WHO expectation and to national statistics. Increasing breast feeding rates should consequently become a priority aim, pursuing it through the health workers training, the support of mothers who encounter difficulties during their hospital stay or at home, and making the public aware of breast feeding practices.

Structural specificities and significance for coeliac disease of wheat gliadin peptides able to agglutinate or to prevent agglutination of K562(S) cells.

Two peptides corresponding to bread wheat A-gliadin fragments 31-43 and 44-55, well known for their ability to damage the coeliac disease intestinal mucosa both in vitro and in vivo, have been confirmed to be very active in inducing in vitro agglutination of K 562 (S) cells. Removal of six amino acid residues from the carboxy-terminal end of the 31-43 peptide, or of five amino acid residues from the amino terminal end of the 44-55 peptide, resulted in a lower, but still very significant, cell agglutination activity. The peptide consisting of ten amino acid residues with a molecular mass of 1157.5 Da, isolated from durum wheat gliadin, was able to prevent agglutination of K 562 (S) cells induced not only by prolamine peptic-tryptic digests from all the cereals toxic in coeliac disease (i.e. bread wheat, rye, barley and oats), but also by the 31-43 and 44-55 peptides. The ability to protect K 562 (S) cells from agglutination was exhibited to the fullest extent also by all the peptides derived from the 1157.5-Da peptide by five progressive deletions of the terminal carboxylic residue, whereas the sixth consecutive deletion yielded a completely inactive peptide. A similar total loss of activity was observed upon addition of a glycine residue to the amino terminal residue of the 1157.5-Da peptide and all the above-mentioned active peptides derived from it. The remarkable sequence homologies existing between peptides able to induce [Gln-Gln-Gln-Pro and -Pro-Ser-Gln-Gln-] or to prevent [H2N-Gln-Gln-Pro-Gln-Asp-COOH] induction of cell agglutination strongly suggest that all these peptides compete for identical or structurally related binding sites on the cell surface.

A small peptide from durum wheat gliadin prevents cell agglutination induced by prolamin-peptides toxic in coeliac disease.

A peptide (m.w. 1157.5 Da) able to prevent the agglutination of K562(S) cells induced by the peptic-tryptic prolamine digests of the cereals toxic in coeliac disease (i.e. bread wheat, rye, barley and oat) was characterized as one of the components of the peptic-tryptic digest of durum wheat gliadin. This peptide was synthesized in a high degree of purity with the solid phase method with the Applied Biosystem 431A. An amino acid sequence was identified in the 1157.5 Da peptide as being related to the largest common sequences previously detected in a series of bread wheat toxic peptides by other authors.

Mannan and oligomers of N-acetylglucosamine protect intestinal mucosa of celiac patients with active disease from in vitro toxicity of gliadin peptides.

Wheat flour and other cereals toxic for celiac patients contain an alcohol-soluble protein fraction that, under experimental conditions simulating in vivo protein digestion, yields peptides that agglutinate undifferentiated K 562(S) cells. In contrast, cereals well tolerated in celiac disease (i.e., rice and maize) do not. Furthermore, purified A-gliadin peptides that damage in vitro-cultured flat celiac mucosa are powerful agglutinins for K 562(S) cells, whereas A-gliadin peptides that do not show any adverse in vitro effect on celiac intestine lack agglutinating activity. Mannan, acetylglucosamine, and its oligomers (N,N'-diacetylchitobiose and N,N',N"-triacetylchitotriose) were able to prevent and reverse cell agglutination induced by peptides from all the toxic cereals. Moreover, mannan and N,N',N"-triacetylchitotriose exhibited a protective effect on intestinal mucosa specimens of patients with active celiac disease cultured with wheat protein-derived peptides. These data are consistent with the hypothesis that the agglutinating and toxic peptides are bound by carbohydrates.

A basis for estimation of consumption: literature values for selected food volatiles. Part III.

Quantitative data on volatile compounds have been reported in 16 food items. No publications reporting quantitative data were found for two of these 16 food products, i.e. avocado and jackfruit. About 550 volatile compounds have been assayed globally in the other 14 food products. Mango and raspberry were the products with the greatest number of volatile compounds; the most representative substances were benzaldehyde, ethyl acetate, limonene, and 2-phenylethanol.

Animal species and strains used to test chemical carcinogens: results of a preliminary study.

The selection of animal species sufficiently representative of human physiological processes and sensitive to a wide spectrum of toxic agents is one of the major problems in toxicology. The aim of this study, based on animal experimental carcinogenesis data available from the literature, was the identification of animal strains most often used in experimental carcinogenesis. The analysis was limited to experiments on chemicals or groups of chemicals classified by IARC under Group 1 of carcinogenic risk (sufficient evidence). For each experiment considered in the study, data concerning animal species, strains, and substrains (whenever possible) were collected. The data analysis has shown that approximately 83 and 61% of the considered carcinogens were tested positively in mouse and rat, respectively, and that A, Swiss, and C3H mouse strains and Sprague-Dawley and Wistar rat strains were used most often. The study has shown that practically all decisions regarding the carcinogenicity of substances are based on the response of only two animal species (mouse and rat). Therefore, a clear and complete understanding of carcinogenicity mechanisms in these species becomes essential in order to extrapolate results to man.

Intestinal mucosa of celiacs in remission is unable to abolish toxicity of gliadin peptides on in vitro developing fetal rat intestine and cultured atrophic celiac mucosa.

Subfraction 2R of fraction 9 from a peptic-tryptic-pancreatic digest of wheat gliadin is known to be toxic in vivo to celiac patients. We have found that fractions 9 and 2R inhibit the in vitro development of fetal rat intestine and the increase of enterocyte height occurring in organ culture of atrophic celiac mucosa (0.1-0.5 mg/ml medium). Other peptide fractions of the gliadin digest are devoid of such in vitro effects. Subfraction 2R, after incubation with morphologically normal small intestinal mucosa of celiacs in remission and ultrafiltration, was still very active in both culture systems at low concentration (0.1 mg/ml); on the contrary, subfraction 2R was inactivated after incubation with normal mucosa. These results are compatible with the hypothesis that there is a mucosal defect in handling gliadin peptides in celiac disease, and suggest that there is either a primary (or secondary) enzyme deficiency or some other mechanism operating in the intestinal mucosa of celiac patients in remission.

Prevention by mannan and other sugars of in vitro damage of rat fetal small intestine induced by cereal prolamin peptides toxic for human celiac intestine.

Peptic-tryptic-cotazym and peptic-tryptic digests were obtained, simulating in vivo protein digestion, from pure "bread" wheat gliadins and from rye, barley, and oats prolamine and tested on small intestine cultures from fetal rats. When tested at a concentration of 0.1 mg of peptides/ml of culture medium the peptic-tryptic-cotazym and peptic-tryptic digests of gliadin and prolamines were very active in slowing in vitro development of fetal rat intestine and in increasing the occurrence and severity of degenerative changes. The ability of some sugars to interfere with inhibition of fetal intestinal morphogenesis induced by these peptides was also tested. Mannan at a concentration of 0.1 mM was effective in allowing intestinal morphogenesis to take place in the presence of prolamine peptic-tryptic-cotazym and prolamine peptic-tryptic digests of the four toxic cereals. Some oligomers of N-acetyl-glucosamine were also effective in blocking the inhibitory effect of "bread" wheat gliadin peptides. These data are compatible with the hypothesis that some sugars may exert a protective effect on the toxic activity of cereal prolamin peptides on the human celiac intestine.

An analysis of cereals that react with serum antibodies in patients with coeliac disease.

Sera from six children with active coeliac disease, and elevated titres against gliadins and from six age-matched controls, were examined for IgG antibodies against different cereal proteins by a solid-phase radioimmunoassay. Antibodies to the major wheat proteins and the prolamines of other cereals were present in low titre in all control sera. In coeliac sera, significantly higher titres were found against A-gliadin, as well as against hexaploid and tetraploid wheat whole gliadins. Gliadin peptic-tryptic digest retained a significant antigenic activity, completely lost by peptic-tryptic-pancreatic digest. High titres were also found when coeliac sera were tested against wheat glutenins, albumins, and globulins, as well as against barley, oats, and maize prolamines; rice prolamines gave lower titres. Serum from whole gliadins and A-gliadin immunized rabbits showed a similar spectrum of reactivity against prolamines as coeliac sera. Our results indicate a dissociation between immunogenic properties of cereal proteins and toxicity in coeliac disease.

A basis for estimation of consumption: literature values for selected food volatiles. Part II.

In this paper we present a compilation of quantitative literature data on volatile compounds in 15 food items including some brandies, meats, oils as well as vegetables, vinegar and potatoes. Levels of the volatile compounds identified (approximately 900) in this group of food items are generally in the ppm range. Carboxylic acids were present in much higher levels in plum brandy, vinegar, lamb and mutton (heated), whereas alcohols, esters and carbonyls aldehydes are particularly abundant in brandy.

An assessment of the safety of tocopherols as food additives.

This paper is a critical review of data relevant to the safety of tocopherols as food additives. Tocopherols are considered from the standpoint of their chemical-physical properties, occurrence in nature and use in commercial products. Dietary intake and kinetic and metabolic data, as well as biological activity and interactions with other vitamins, are also examined. The subjects discussed include acute, subchronic and chronic toxicity data, reproduction and teratogenesis studies, and observations in humans following high intakes of tocopherols. On the basis of the comprehensive experimental and clinical data available on alpha-tocopherol, the chemical and biological similarity of the alpha-, beta-, gamma- and delta-tocopherols and the information available on the levels of tocopherols used as food antioxidants, it is concluded that tocopherols are safe food additives.

A basis for estimation of consumption: literature values for selected food volatiles. Part I.

This paper is a compilation of quantitative data available on volatile compounds reported so far in 18 food items including some legume, cereals, grapes and cheeses as well as crab, lobster, cocoa and chocolate. No publications reporting quantitative data were found for five of these 18 food products, i.e. sultana grape, broad beans, cassava, oat and rye. About 440 volatile compounds have been assayed globally in the other 13 food products and more than 50% of them were found in grape or in grape juice. Levels of these volatile compounds in the selected foods were generally in the ppb range and less often in the low ppm range. Very high levels were found for some carboxylic acids in cheeses and cocoa and for some alcohols and acids as well as for ethyl acetate in grape juice.