Becker H.,Federal Environment Agency UBA |
Herzberg F.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Schulte A.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Kolossa-Gehring M.,Federal Environment Agency UBA
International Journal of Hygiene and Environmental Health | Year: 2011
A summary of a critical review by a working group of the German Federal Environment Agency and the German Federal Institute for Risk Assessment on the carcinogenic potential of nanomaterials is presented. After a critical review of the available data, we conclude that the potential carcinogenic risk of nanomaterials can currently be assessed only on a case-by-case basis. There is certain evidence that different forms of CNTs (carbon nanotubes) and nanoscale TiO 2 particles may induce tumours in sensitive animal models. It is assumed that the mode of action of the inhalation toxicity of asbestos-like fibres and of inhalable fractions of biopersistent fine dusts of low toxicity (nano-TiO 2) is linked to chronic inflammatory processes. Existing epidemiological studies on carcinogenicity for these manufactured nanomaterials are not sufficiently conclusive.Generally speaking, the database is not adequate for an assessment of the carcinogenic potential of nanomaterials. Whereas a number of studies provide evidence of a nano-specific potential to induce tumours, other studies did not. This is possibly due to insufficient characterisation of the test material, difference in the experimental design, the use of different animal models and species and/or differences in dosimetry (both with regard to the appropriate dose metric and the estimated effective dose quantities).An assessment of the carcinogenic potential and its relevance for humans are currently fraught with uncertainty. Furthermore, the nano-specificity of the carcinogenic effects observed cannot be conclusively evaluated. Specific carcinogenic effects of nanomaterials may be both quantitative and qualitative. In quantitative terms, the carcinogenic effects of nanoparticles are thought to be simply more pronounced compared to the corresponding bulk material (due, for example, to the considerably larger surface area and higher number of particles relative to the mass concentration). On the other hand, certain nano-properties such as small size, shape and reactivity, retention time and distribution in the body after overcoming biological barriers, as well as subcellular and molecular interactions may play a role in determining the toxicity in qualitative terms, i.e. the carcinogenic potential of the nanomaterial and the non-nanoscale comparison substance may be fundamentally different.All of these factors leave no doubt about the fact that there is a great need for research in this area and that new standardised test methods need to be developed or existing ones adapted at the very least to achieve valid answers regarding the carcinogenic potential of nanomaterials. Global production of nanomaterials is set to increase in the years to come, and new materials with new properties will be developed, so that greater human exposure to them must be anticipated.No reliable conclusions can currently be drawn about exposure to nanoparticles and their release from products. Firstly, there are substantial deficits in information about the processing of nanomaterials in products and preparations. Secondly, there are only a small number of studies on nanoparticle release, and reliable techniques for measuring and monitoring nanomaterials in different environmental media are still being developed which is both complex and costly.Despite the uncertainties, the findings to date on the carcinogenic potential of nanomaterials must be taken seriously, and precautionary measures to minimise exposure should go hand in hand with the development of a comprehensive and conclusive toxicological methodology and testing procedure for nanostructured materials that includes all possible exposure routes.With regard to possible legal classification of nanomaterials and the transferability of classifications of their non-nanomaterial counterparts, we believe it is necessary to have separate procedures for nano and non-nano forms. Furthermore, criteria for evaluating nano-specific carcinogenic properties should be constantly updated and adapted to the state of knowledge. There is a need here for amendments to be made to EU legislation, as currently nanoforms do not represent a separate category of substance in their own right. © 2010 Elsevier GmbH.
Pryshliak M.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Hammerl J.A.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Reetz J.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Strauch E.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Hertwig S.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung
PLoS ONE | Year: 2014
Background: Vibrio vulnificus is an important pathogen which can cause serious infections in humans. Yet, there is limited knowledge on its virulence factors and the question whether temperate phages might be involved in pathogenicity, as is the case with V. cholerae. Thus far, only two phages (SSP002 and VvAW1) infecting V. vulnificus have been genetically characterized. These phages were isolated from the environment and are not related to Vibrio cholerae phages. The lack of information on temperate V. vulnificus phages prompted us to isolate those phages from lysogenic strains and to compare them with phages of other Vibrio species. Results: In this study the temperate phage PV94 was isolated from a V. vulnificus biotype 1 strain by mitomycin C induction. PV94 is a myovirus whose genome is a linear double-stranded DNA of 33,828 bp with 5′-protruding ends. Sequence analysis of PV94 revealed a modular organization of the genome. The left half of the genome comprising the immunity region and genes for the integrase, terminase and replication proteins shows similarites to V. cholerae kappa phages whereas the right half containing genes for structural proteins is closely related to a prophage residing in V. furnissii NCTC 11218. Conclusion: We present the first genomic sequence of a temperate phage isolated from a human V. vulnificus isolate. The sequence analysis of the PV94 genome demonstrates the wide distribution of closely related prophages in various Vibrio species. Moreover, the mosaicism of the PV94 genome indicates a high degree of horizontal genetic exchange within the genus Vibrio, by which V. vulnificus might acquire virulence-associated genes from other species. © 2014 Pryshliak et al.
Heinemeyer G.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Sommerfeld C.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Springer A.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
Heiland A.,Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung |
And 5 more authors.
International Journal of Hygiene and Environmental Health | Year: 2013
In the study presented here, we evaluated the exposure of the German population aged 14-80 years to bis(2-ethylhexyl)phthalate (DEHP) from consumption of food by means of deterministic and probabilistic estimations. The study was performed on the basis of an extensive review of literature from around the world reporting measured data on DEHP in food, as well as official German food control data. Only data from individual measurements were considered and used for fitting of distributions. A wide range of concentrations in non-representative samples are reported in the literature. On the basis of the available DEHP concentration data, 37 food categories were characterized which covered all major food classes. Food consumption data were taken from the diet history interviews of the German National Nutrition Survey II (Nationale Verzehrsstudie II) which was performed in 2005/2006 in a representative study population of 15,371 and is the most recent data source of this kind in Germany. Average DEHP intake was estimated deterministically using data on measured concentrations in food (medians and means) and food consumption (means). A total dietary exposure to DEHP of 3.6 (median based) and 9.3 μg/kg of BW per day (based on mean values) was estimated deterministically. In addition, distributions of both concentrations and consumption figures were fitted using the @RISK best fit tool for further probabilistic estimations. This approach resulted in estimates within the same range: the estimated median DEHP intake in the whole population (both non-consumers and consumers of the foods considered) was 10.2, the arithmetic mean 14.0 and the 95th percentile 28.6 μg/kg of BW per day. The respective estimates for consumers only were 12.4, 18.7 and 36.5 μg/kg of BW per day. These results demonstrate that the probabilistic approach is able to estimate broader ranges of exposure even when using data representing an average intake. Moreover, it reflects the uncertainties of the estimation due to insufficient analytical data on concentrations of DEHP in food. © 2013 Elsevier GmbH.
PubMed | Federal Institute For Risk Assessment Bundesinstitut For Risikobewertung
Type: Journal Article | Journal: Genome announcements | Year: 2014
We report here the 79,263-bp plasmid pVv01 isolated from Vibrio vulnificus. pVv01 is closely related to the Vibrio plasmid p0908 and shows some similarities to phage P1. Unlike p0908, pVv01 represents an intact prophage inducible by mitomycinC. PVv01 phage particles revealed a myoviridal morphology and lytic activity.