IVAM UvA BV

Amsterdam, Netherlands

IVAM UvA BV

Amsterdam, Netherlands

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Kettler K.,Radboud University Nijmegen | Krystek P.,VU University Amsterdam | Krystek P.,IVAM UvA BV | Giannakou C.,National Institute for Public Health and the Environment RIVM | And 3 more authors.
Journal of Nanoparticle Research | Year: 2016

The increasing number of nanotechnology products on the market poses increasing human health risks by particle exposures. Adverse effects of silver nanoparticles (AgNPs) in various cell lines have been measured based on exposure dose after a fixed time point, but NP uptake kinetics and the time-dependent internal cellular concentration are often not considered. Even though knowledge about relevant timescales for NP uptake is essential, e.g. for time- and cost-effective risk assessment through modelling, insufficient data are available. Therefore, the authors examined uptake rates for three different AgNP sizes (20, 50 and 75 nm) and two tissue culture medium compositions (with and without foetal calf serum, FCS) under realistic exposure concentrations in pulmonary epithelial 16HBE14o-cells. The quantification of Ag in cells was carried out by high-resolution inductively coupled plasma mass spectrometry. We show for the first time that uptake kinetics of AgNPs into 16HBE14o-cells was highly influenced by medium composition. Uptake into cells was higher in medium without FCS, reaching approximately twice the concentration after 24 h than in medium supplemented with FCS, showing highest uptake for 50-nm AgNPs when expressed on a mass basis. This optimum shifts to 20 nm on a number basis, stressing the importance of the measurand in which results are presented. The importance of our research identifies that not just the uptake after a certain time point should be considered as dose but also the process of uptake (timing) might need to be considered when studying the mechanism of toxicity of nanoparticles. © 2016, The Author(s).


Fernandez-Fueyo E.,Technical University of Delft | Van Wingerden M.,Technical University of Delft | Renirie R.,IVAM UvA BV | Wever R.,University of Amsterdam | And 3 more authors.
ChemCatChem | Year: 2015

The vanadium-dependent chloroperoxidase from Curvularia inaequalis is an efficient biocatalyst for the in situ generation of hypohalous acids and subsequent electrophilic oxidation/halogenation reactions. Especially, its superb activity and stability under operational conditions make it an attractive catalyst for organic synthesis. Herein, the efficient bromination of thymol was investigated, and turnover numbers of the enzyme were found to exceed 2 000 000. The major novelty of the work is that vanadium chloroperoxidase is more useful as a brominating enzyme than vanadium bromoperoxidase in terms of operational stability, besides being far more stable than heme-containing peroxidases. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Van Broekhuizen P.,IVAM UvA BV | Van Broekhuizen F.,IVAM UvA BV | Cornelissen R.,IVAM UvA BV | Reijnders L.,University of Amsterdam
Journal of Nanoparticle Research | Year: 2012

Nano reference values (NRVs) for occupational use of nanomaterials were tested as provisional substitute for Occupational Exposure Limits (OELs). NRVs can be used as provisional limit values until Health-Based OELs or derived no-effect levels (DNEL) become available. NRVs were defined for 8 h periods (time weighted average) and for short-term exposure periods (15 min-time weighted average). To assess the usefulness of these NRVs, airborne number concentrations of nanoparticles (NPs) in the workplace environment were measured during paint manufacturing, electroplating, light equipment manufacturing, non-reflective glass production, production of pigment concentrates and car refinishing. Activities monitored were handling of solid engineered NPs (ENP), abrasion, spraying and heating during occupational use of nanomaterials (containing ENPs) and machining nanosurfaces. The measured concentrations are often presumed to contain ENPs as well as process-generated NPs (PGNP). The PGNP are found to be a significant source for potential exposure and cannot be ignored in risk assessment. Levels of NPs identified in workplace air were up to several millions of nanoparticles/ cm 3. Conventional components in paint manufacturing like CaCO 3 and talc may contain a substantial amount of nanosized particulates giving rise to airborne nanoparticle concentrations. It is argued that risk assessments carried out for e.g. paint manufacturing processes using conventional non-nano components should take into account potential nanoparticle emissions as well. The concentrations measured were compared with particle-based NRVs and with massbased values that have also been proposed for workers protection. It is concluded that NRVs can be used for risk management for handling or processing of nanomaterials at workplaces provided that the scope of NRVs is not limited to ENPs only, but extended to the exposure to process-generated NPs as well. © Springer Science+Business Media B.V. 2012.


Van Broekhuizen P.,IVAM UvA BV | Reijnders L.,University of Amsterdam
Annals of Occupational Hygiene | Year: 2012

This article summarizes the outcome of the discussions at the international workshop on nano reference values (NRVs), which was organized by the Dutch trade unions and employers' organizations and hosted by the Social Economic Council in The Hague in September 2011. It reflects the discussions of 80 international participants representing small- and medium-size enterprises (SMEs), large companies, trade unions, governmental authorities, research institutions, and non-governmental organizations (NGOs) from many European countries, USA, India, and Brazil. Issues that were discussed concerned the usefulness and acceptability of precaution- based NRVs as a substitute for health-based occupational exposure limits (OELs) and derived no-effect levels (DNELs) for manufactured nanoparticles (NPs). Topics concerned the metrics for measuring NPs, the combined exposure to manufactured nanomaterials (MNMs) and process-generated NPs, the use of the precautionary principle, the lack of information about the presence of nanomaterials, and the appropriateness of soft regulation for exposure control. The workshop concluded that the NRV, as an 8-h time-weighted average, is a comprehensible and useful instrument for risk management of professional use of MNMs with a dispersible character. The question remains whether NRVs, as advised for risk management by the Dutch employers' organization and trade unions, should be under soft regulation or that a more binding regulation is preferable. © The Author 2012.


Van Broekhuizen P.,IVAM UvA BV | Van Broekhuizen F.,IVAM UvA BV | Cornelissen R.,IVAM UvA BV | Reijnders L.,University of Amsterdam
Journal of Nanoparticle Research | Year: 2011

In the European construction industry in 2009, the use of engineered nanoparticles appears to be confined to a limited number of products, predominantly coatings, cement and concrete. A survey among representatives of workers and employers from 14 EU countries suggests a high level of ignorance about the availability and use of nanomaterials for the construction industry and the safety aspects thereof. Barriers for a large-scale acceptance of products containing engineered nanoparticles (nanoproducts) are high costs, uncertainties about long-term technical material performance, as well as uncertainties about health risks of nanoproducts. Workplace measurements suggest a modest exposure of construction workers to nanoparticles (NPs) associated with the use of nanoproducts. The measured particles were within a size range of 20-300 nm, with the median diameter below 53 nm. Positive assignment of this exposure to the nanoproduct or to additional sources of ultrafine particles, like the electrical equipment used was not possible within the scope of this study and requires further research. Exposures were below the nano reference values proposed on the basis of a precautionary approach. © Springer Science+Business Media B.V. 2011.


Van Broekhuizen P.,IVAM UvA BV | Dorbeck-Jung B.,University of Twente
Journal of Occupational and Environmental Hygiene | Year: 2013

In the European Union, the legal obligation for employers to provide a safe workplace for processing manufactured nanomaterials is a challenge when there is a lack of hazard information. The attitude of key stakeholders in industry, trade unions, branch and employers' organizations, and government policy advisors toward nano reference values (NRVs) has been investigated in a pilot study that was initiated by a coalition of Dutch employers' organizations and Dutch trade unions. NRVs are developed as provisional substitutes for health-based occupational exposure limits or derived no-effect levels and are based on a precautionary approach. NRVs have been introduced as a voluntary risk management instrument for airborne nanomaterials at the workplace. A measurement strategy to deal with simultaneously emitting processgenerated nanoparticles was developed, allowing employers to use the NRVs for risk assessment. The motivational posture of most companies involved in the pilot study appears to be pro-active regarding worker protection and acquiescent to NRVs. An important driver to use NRVs seems to be a temporary certainty employers experience with regard to their legal obligation to take preventive action. Many interviewees welcome the voluntary character of NRVs, though trade unions and a few companies advocate a more binding status. Copyright © 2013 JOEH, LLC.


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Social Sciences | Award Amount: | Year: 2001

None


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Social Sciences | Award Amount: | Year: 2002

The Industrial Ecology (IE) programme at IVAM addresses implementation issues for different types of enterprises. Customised, non-vulnerable tools play a crucial role in facilitating the implementation of Industrial Ecology in enterprises. IE tools enable enterprises to organise their IE activities and to identify, evaluate and implement environmental improvements in production chains and processes, products, services and buildings. The IE toolbox developed and promoted is based on a division in four functional categories of tools, respectively: 1. inventory tools enabling the identification, quantification and allocation of environmental interventions related to production processes, products or life cycles. In this perspective, environmental interventions should be regarded as material- and energy inputs and non-product material and energy outputs (discharge of emissions and waste generation) 2. prioritisation tools providing structured approaches with well specified criteria for the evaluation of, and priority setting among, environmental interventions and/or environmental improvement options 3. improvement tools facilitating the generation of improvement options for products, production processes and life cycles in different stages of the value chain, the process flow (material cycle) and/or innovation cycle 4. management tools procedures and/or routines for the execution of IE projects. These tools specify and allocate tasks, ensure involvement from key persons, departments and organisations, and assist in keeping track of progress achieved. For each category of tools, several example tools have been described as well as strengths and weaknesses of their practical application in the Dutch manufacturing industry. Since 1996, IVAM Environmental Research is working with industry to develop customised decision making tools for selected industry sectors. Noteworthy are in particular the following: environmental decision making tool for food processing industry this tool is meant to support the environmental assessment of food production chains and to facilitate the exchange of environmental information, in order to enable product developers to select environmental improvement options for their products. So far, a standardised procedure has been developed for collecting environmental information of the production of food commodities. The procedure has been applied for five commodities (milk powder, soy bean oil, pork, potato starch and beet sugar) environmental decision making tool for architects this tool is meant to assist architects in different stages of the design of a building. A standardised routine has been developed to allocate environmental impacts to building components and utility systems (as opposed to construction materials in traditional LCAs). Alternative building designs are presently being evaluated as well as opportunities explored to transfer the tool into a user-friendly software application for architects environmental process diagnosis and improvement tool this tool aims to support the generation of environmental improvement opportunities for industrial processes. The tool is based on a taxonomy of source features and cause features, which guide the user with a computerised question and answer session to a set of improvement opportunities which target the specific features of a particular process (this tool development is supported with a grant from the Lucent Foundation). And most recently, research has been started on Environmental Benefits from the dematerialisation of services The AT&T Industrial Ecology Faculty Fellowship sponsors an exploratory study on the assessment of environmental benefits from the dematerialization of services. The process of dematerialization is thought to consist of the substitution of information for other inputs (materials, energy, and transportation) in the provision of the respective service. The study addresses how to assess whether the transition towards information in


Fernandez-Fueyo E.,Technical University of Delft | Younes S.H.H.,Technical University of Delft | Younes S.H.H.,Sohag University | Van Rootselaar S.,Radboud University Nijmegen | And 6 more authors.
ACS Catalysis | Year: 2016

A catalytic, enzyme-initiated (aza-) Achmatowicz reaction is presented. The involvement of a robust vanadium-dependent peroxidase from Curvularia inaequalis allows the simple use of H2O2 and catalytic amounts of bromide. © 2016 American Chemical Society.


PubMed | IVAM UvA BV
Type: Consensus Development Conference | Journal: The Annals of occupational hygiene | Year: 2012

This article summarizes the outcome of the discussions at the international workshop on nano reference values (NRVs), which was organized by the Dutch trade unions and employers organizations and hosted by the Social Economic Council in The Hague in September 2011. It reflects the discussions of 80 international participants representing small- and medium-size enterprises (SMEs), large companies, trade unions, governmental authorities, research institutions, and non-governmental organizations (NGOs) from many European countries, USA, India, and Brazil. Issues that were discussed concerned the usefulness and acceptability of precaution-based NRVs as a substitute for health-based occupational exposure limits (OELs) and derived no-effect levels (DNELs) for manufactured nanoparticles (NPs). Topics concerned the metrics for measuring NPs, the combined exposure to manufactured nanomaterials (MNMs) and process-generated NPs, the use of the precautionary principle, the lack of information about the presence of nanomaterials, and the appropriateness of soft regulation for exposure control. The workshop concluded that the NRV, as an 8-h time-weighted average, is a comprehensible and useful instrument for risk management of professional use of MNMs with a dispersible character. The question remains whether NRVs, as advised for risk management by the Dutch employers organization and trade unions, should be under soft regulation or that a more binding regulation is preferable.

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