Nicoleta Suciu

Recycled paper-paperboard for food contact materials: Contaminants suspected and migration into foods and food simulant

Contaminant residues in food packaging is a new challenge of our time, as it may pose a threat for consumers. Higher levels of contaminants were observed in food packaging made by recycled materials, even if little information is available for some groups of contaminants. The present study proposes a procedure for analyzing three different groups of organic contaminants in recycled paper and paperboard. Seventeen commercial samples were analyzed for the presence of bisphenol A (BPA), bis (2-ethylhexyl) phthalate (DEHP), nonylphenol monoethoxylate (NMP) and nonylphenol di-ethoxilate (NDP). Not all the samples contained all the contaminants; BPA was the only substance present in all the samples. The concentrations detected were quite high and, in most of the cases, in agreement with results reported in previous studies. Substance migration tests from spiked/non-spiked samples for two dry foods and Tenax® food simulant were undertaken. BPA migration quotients were always lower than 1%, whereas the migration quotients of DEHP were higher than 2.0%. The highest nonylphenols migration quotients were 6.5% for NMP and 8.2% for NDP. Tenax® simulates well the contaminants migration from paperboard to dry food, in some cases being even more severe than the food.

Adsorption of chlorpyrifos, penconazole and metalaxyl from aqueous solution by modified clays

Sorption of three pesticides (chlorpyrifos, metalaxyl and penconazole) has been measured on a commercial clay montmorillonite and on the same mineral modified with either of two cationic-surfactant micelles. Both micelle–clay complexes, commercial names Cloisite 20A and Cloisite 30B, showed a good capacity to sorb all three pesticides from water, whereas their sorption on the natural montmorillonite was not described by an isotherm. Modelling sorption on both micelle–clay complexes showed that the Freundlich sorption constant (K F) was higher for chlorpyrifos on Cloisite 20A (K F = 7.76) than on Cloisite 30B (K F = 5.91), whereas the sorption of metalaxyl was stronger on Cloisite 30B (K F = 1.07) than on Cloisite 20A (K F = 0.57). Moreover the micelle–clay complex Cloisite 20A also showed a good affinity for penconazole, the maximum quantity adsorbed (q m) of 6.33 mg g−1 being 45% more than that on Cloisite 30B. Single-batch adsorption of each pesticide onto both micelle–clay complexes was studied using the Freundlich isotherm for chlorpyrifos and metalaxyl and the Langmuir isotherm for penconazole. The Cloisite 20A micelle–clay complex was predicted to require 23% less adsorbent to treat certain volumes of wastewater containing 30 mg L−1 chlorpyrifos, 43% more to treat metalaxyl similarly and 57% less to treat penconazole compared with Cloisite 30B.

PAHs content of sewage sludge in Europe and its use as soil fertilizer.

The European Commission has been planning limits for organic pollutants in sewage sludge for 14years; however no legislation has been implemented. This is mainly due to lack of data on sewage sludge contamination by organic pollutants, and possible negative effects to the environment. However, waste management has become an acute problem in many countries. Management options require extensive waste characterization, since many of them may contain compounds which could be harmful to the ecosystem, such as heavy metals, organic pollutants. The present study aims to show the true European position, regarding the polycyclic aromatic hydrocarbons (PAHs) content of sewage sludge, by comparing the Italian PAHs content with European Union countries, and at assessing the suitability of sewage sludge as soil fertilizer. The FOCUS Pearl model was used to estimate the concentration of benzo [a] pyrene (B(a)Pyr), the most toxic PAH in soil, and its exposure to organisms was then evaluated. The simulated B(a)Pyr and PAHs, expressed as B(a)Pyr, concentrations in soil were much lower than the B(a)Pyrs most conservative lowest observable effect concentration (LOEC) for soil organisms. Furthermore, the results obtained indicate that it is more appropriate to apply 5tha(-1) sewage sludge annually than 15tha(-1) triennially. Results suggest, the EU maximum recommended limit of 6mgkg(-)(1) PAHs in sewage sludge, should be conservative enough to avoid groundwater contamination and negative effects on soil organisms.

Modelling the exposure to chemicals for risk assessment: a comprehensive library of multimedia and PBPK models for integration, prediction, uncertainty and sensitivity analysis - the MERLIN-Expo tool

MERLIN-Expo is a library of models that was developed in the frame of the FP7 EU project 4FUN in order to provide an integrated assessment tool for state-of-the-art exposure assessment for environment, biota and humans, allowing the detection of scientific uncertainties at each step of the exposure process. This paper describes the main features of the MERLIN-Expo tool. The main challenges in exposure modelling that MERLIN-Expo has tackled are: (i) the integration of multimedia (MM) models simulating the fate of chemicals in environmental media, and of physiologically based pharmacokinetic (PBPK) models simulating the fate of chemicals in human body. MERLIN-Expo thus allows the determination of internal effective chemical concentrations; (ii) the incorporation of a set of functionalities for uncertainty/sensitivity analysis, from screening to variance-based approaches. The availability of such tools for uncertainty and sensitivity analysis aimed to facilitate the incorporation of such issues in future decision making; (iii) the integration of human and wildlife biota targets with common fate modelling in the environment. MERLIN-Expo is composed of a library of fate models dedicated to non biological receptor media (surface waters, soils, outdoor air), biological media of concern for humans (several cultivated crops, mammals, milk, fish), as well as wildlife biota (primary producers in rivers, invertebrates, fish) and humans. These models can be linked together to create flexible scenarios relevant for both human and wildlife biota exposure. Standardized documentation for each model and training material were prepared to support an accurate use of the tool by end-users. One of the objectives of the 4FUN project was also to increase the confidence in the applicability of the MERLIN-Expo tool through targeted realistic case studies. In particular, we aimed at demonstrating the feasibility of building complex realistic exposure scenarios and the accuracy of the modelling predictions through a comparison with actual measurements.

Bacterial diversity in a contaminated Alpine glacier as determined by culture-based and molecular approaches

Glaciers are important ecosystems, hosting bacterial communities that are adapted to cold conditions and scarcity of available nutrients. Several works focused on the composition of bacterial communities in glaciers and on the long-range atmospheric deposition of pollutants in glaciers, but it is not clear yet if ski resorts can represent a source of point pollution in near-by glaciers, and if these pollutants can influence the residing bacterial communities. To test these hypotheses, 12 samples were analyzed in Madaccio Glacier, in a 3200 ma.s.l. from two areas, one undisturbed and one close to a summer ski resort that is active since the 1930s. Chemical analyses found concentrations up to 43 ng L(-1) for PCBs and up to 168 μg L(-1) for PAHs in the contaminated area: these values are significantly higher than the ones found in undisturbed glaciers because of long-range atmospheric deposition events, and can be explained as being related to the near-by ski resort activities. Isolation of strains on rich medium plates and PCR-DGGE analyses followed by sequencing of bands allowed the identification of a bacterial community with phylogenetic patterns close to other glacier environments, with Proteobacteria and Actinobacteria the mostly abundant phyla, with Acidobacteria, Firmicutes and Cyanobacteria also represented in the culture-independent analyses. A number of isolates were identified by molecular and biochemical methods as phylogenetic related to known xenobiotic-degrading strains: glaciers subjected to chemical contamination can be important reservoirs of bacterial strains with potential applications in bioremediation.

Development of a standard documentation protocol for communicating exposure models

An important step in building a computational model is its documentation; a comprehensive and structured documentation can improve the model applicability and transparency in science/research and for regulatory purposes. This is particularly crucial and challenging for environmental and/or human exposure models that aim to establish quantitative relationships between personal exposure levels and their determinants. Exposure models simulate the transport and fate of a contaminant from the source to the receptor and may involve a large set of entities (e.g. all the media the contaminants may pass though). Such complex models are difficult to be described in a comprehensive, unambiguous and accessible way. Bad communication of assumptions, theory, structure and/or parameterization can lead to lack of confidence by the user and it may be source of errors. The goal of this paper is to propose a standard documentation protocol (SDP) for exposure models, i.e. a generic format and a standard structure by which all exposure models could be documented. For this purpose, a CEN (European Committee for Standardisation) workshop was set up with objective to agree on minimum requirements for the amount and type of information to be provided on exposure models documentation along with guidelines for the structure and presentation of the information. The resulting CEN workshop agreement (CWA) was expected to facilitate a more rigorous formulation of exposure models description and the understanding by users. This paper intends to describe the process followed for defining the SDP, the standardisation approach, as well as the main components of the SDP resulting from a wide consultation of interested stakeholders. The main outcome is a CEN CWA which establishes terms and definitions for exposure models and their elements, specifies minimum requirements for the amount and type of information to be documented, and proposes a structure for communicating the documentation to different users.

Potential for MERLIN-Expo, an advanced tool for higher tier exposure assessment, within the EU chemical legislative frameworks

MERLIN-Expo merges and integrates advanced exposure assessment methodologies, allowing the building of complex scenarios involving several pollution sources and targets. The assessment of exposure and risks to human health from chemicals is of major concern for policy and ultimately benefits all citizens. The development and operational fusion of the advanced exposure assessment methodologies envisaged in the MERLIN-Expo tool will have a significant impact in the long term on several policies dealing with chemical safety management. There are more than 30 agencies in Europe related to exposure and risk evaluation of chemicals, which have an important role in implementing EU policies, having especially tasks of technical, scientific, operational and/or regulatory nature. The main purpose of the present paper is to introduce MERLIN-Expo and to highlight its potential for being effectively integrated within the group of tools available to assess the risk and exposure of chemicals for EU policy. The main results show that the tool is highly suitable for use in site-specific or local impact assessment, with minor modifications it can also be used for Plant Protection Products (PPPs), biocides and REACH, while major additions would be required for a comprehensive application in the field of consumer and worker exposure assessment.

Tracking Global Flows of E-Waste Additives by Using Substance Flow Analysis, with a Case Study in China

The ongoing process of globalization and global trade of products have been an important topic in media as well as in social and economic science. Overlaid by the well-known global trade pathways for feedstock and products, a reverse flow of end-of-life products has been happening for many years. This is especially true for the case of electric and electronic equipment (WEEE). Global flows of WEEE occurred to become an emerging topic of waste management in the past two decades. E-Waste has to be distinguished from materials like paper or PET-bottles, although their recycling is of environmental concern as well. WEEE is not directly recyclable but needs to be processed in several steps to extract the valuable material to be recycled. Several research projects have been carried out on the global flow of WEEE, all suffering from scarce and scattered data and a lack of uniform labelling. To assess the volume of e-waste shipped around the world, an extensive literature research has been carried out. The tool of substance flow analysis (SFA) has been identified as valuable instrument to track global WEEE trade. Data from the e-waste flows have been combined with literature-based chemical data on lead (Pb) and brominated flame retardants (BFRs) and with information on the material composition of WEEE. Several levels of e-waste trade have been addressed: from a global view down to the country level of China to finally focus on a case study of a municipality (Guiyu, China). The processes of informal recycling in China and Guiyu have been introduced to assess the releases of hazardous substances to the environment. The release stages have then been prepared for further use in environmental modelling presented in the chapter “Human and Environmental Impact Produced by E-waste Releases at Guiyu Region (China)” to be found in this publication.

Environmental Fate Models

The environmental fate of chemicals describes the processes by which chemicals move and are transformed into the environment. Environmental fate processes that should be addressed include: persistence in air, water and soil; reactivity and degradation; migration in groundwater; removal from effluents by standard wastewater treatment methods and bioaccumulation in aquatic or terrestrial organisms. Environmental fate models are by no means compulsory for managing priority substances. Efficient source control can be done without them, i.e. by reducing emissions gradually and monitoring the environment to track changes. However the environmental fate models are proposed for use for two main reasons: (a) because the quantitative models can improve the understanding of the managed system and (b) because the models can be used to predict long-term impacts of planned actions. Furthermore the residence times of some of the priority substances may be very long (e.g. 50 years for mercury in water column); therefore, only monitoring could be not enough to detect if the taken measures are enough to reach the good ecological status. The use of environmental fate models in decision making is not a new concept. They are routinely used in the framework of environmental risk assessment. The output of environmental fate models can be expressed as time series of predicted concentrations in different medium of both indoor and outdoor environments.

A Revision of Current Models for Environmental and Human Health Impact and Risk Assessment for Application to Emerging Chemicals

Nowadays, we are living in the global circular economy, where products are produced, used, and finally disposed in different parts of the world. These products have a huge amount of additives, that in many cases can be hazardous if they are not treated properly. The risk assessment of human health and the environment due to exposure to chemical additives is necessary.