Documents Krug, Harald 5 results

"Major accident regulations aim at protecting the population and the environment from possible accidental releases of chemicals. To achieve this goal, the regulations need to be reassessed in light of the development of new technologies. A currently rapidly growing new technology is nanotechnology, and engineered nanomaterials (ENM) are already produced and used in commercial products. The aim of this work was therefore to evaluate the current knowledge on human and ecotoxicology of ENM and their release and behavior in the environment in the context of major accident prevention. Nano-specific release paths are not to be expected. The established safety standards in the chemical industry are also applicable to ENM, especially the separate storage of flammable solvents and detention reservoirs. The potential of a release to the environment of ENM in powder form is larger than for suspensions; however, it can be minimized by safety measures established for conventional dusts. The considered human toxicology studies show that to date not conclusive enough answers regarding the toxicity of ENM can be made. The effects are dependent not only on the material itself but more on the functionalization, surface reactivity, size, and form. The acute ecotoxicity of ENM seems to be similar to the one of the corresponding microparticles (TiO2) or the respective dissolved ions (Ag, Zn) with the exception of photocatalytically active nano-TiO2, which has an increased toxicity. In order to guarantee that all ENM are included in the existing major accident regulations, different classification options are possible and the advantages and disadvantages are discussed. An important step will be the compulsory inclusion of nano-specific data in the Material Safety Data Sheets that serve as the basic medium to transfer information from the manufacturer to downstream users and authorities. We also call for a regular monitoring of the production and uses for ‘high production volume ENM' that could have the largest implications for major accident regulations."

"The increasing consumption of products containing nanomaterials that can be currently observed and forecasts of new developments and applications fan the fear of individuals and organizations regarding new risks to health. Considering experiences gained from previous technology developments, such fears are not completely unfounded. But are they really justified? And is it justified, moreover, to speak of “nanotoxicology” as a new discipline? This Review seeks to cast light on the phenomena that may occur as nanoobjects interact with cells, tissues, and organisms. Furthermore, we will demonstrate that the many data made available on the biological effects of nanomaterials do not always come from studies that can be considered reliable. We will point out the aspect of reliability with specific examples from the literature and will not address specific (nano)materials. In particular, inadequate methods will be described together with recommendations how to avoid this in the future, thereby contributing to a sustainable improvement of the available data."

"Nanosilver is one nanomaterial that is currently under a lot of scrutiny. Much of the discussion is based on the assumption that nanosilver is something new that has not been seen until recently and that the advances in nanotechnology opened completely new application areas for silver. However, we show in this analysis that nanosilver in the form of colloidal silver has been used for more than 100 years and has been registered as a biocidal material in the United States since 1954. Fifty-three percent of the EPA-registered biocidal silver products likely contain nanosilver. Most of these nanosilver applications are silver-impregnated water filters, algicides, and antimicrobial additives that do not claim to contain nanoparticles. Many human health standards for silver are based on an analysis of argyria occurrence (discoloration of the skin, a cosmetic condition) from the 1930s and include studies that considered nanosilver materials. The environmental standards on the other hand are based on ionic silver and may need to be re-evaluated based on recent findings that most silver in the environment, regardless of the original silver form, is present in the form of small clusters or nanoparticles. The implications of this analysis for policy of nanosilver is that it would be a mistake for regulators to ignore the accumulated knowledge of our scientific and regulatory heritage in a bid to declare nanosilver materials as new chemicals, with unknown properties and automatically harmful simply on the basis of a change in nomenclature to the term “nano”."

"Gold nanoparticles have been reported to cross the placenta after maternal intravenous injection in rats, but structural and physiologic differences across species preclude inferences about the ability of nanoparticles to cross human placentas based on animal studies. Wick et al. (p. 432) used an ex vivo human placental perfusion model to study the transfer of fluorescent polystyrene particles (nominal diameters of 50, 80, 240, and 500 nm) across the placenta. The authors report that polystyrene particles up to 240 nm in diameter were able to cross the placental barrier without affecting the viability of the placental explant. The authors conclude that findings are consistent with size-dependent transfer of nanomaterials across human placentas, but they acknowledge that the model involved high-dose exposures over a period of a few hours and that the perfusion rate was representative of placental perfusion late in pregnancy. In addition, they suggest that transfer may also be influenced by particle composition or surface coatings, thus preventing generalization across different types of nanoparticles."

"Since nanotechnology is considered a key for the 21st century, its promises have been assessed by various scientific communities. By meeting at the nanoscale, various disciplines, from physics via chemistry to biology, from engineering to medicine, contribute synergetically to the newly created knowledge base and the resulting technological advances. Considering that large societal sectors will be impacted, the unique aspect of this two-year study was to assess nanotechnology from various interrelated perspectives: scientific progress, industrial relevance, economic potential, educational needs, potential adverse health effects, and philosophical aspects.
The goal of this study was to derive integrated recommendations which consider the large range of societal implications reflecting the different views in an integrative manner. The study attempts to link previously isolated statements, bundling the various concepts and giving unified recommendations to decision makers in relevant society sectors such as politics, economy and research. Special attention was given to the European situation with respect to commercial consequences, an aspect that has not yet received the attention it deserves so far."