Preface Free

The occurrence of pollutants of nanometre size, i.e., nanopollutants, in the environment has been a global concern and a hot research and legislation topic in recent years. The editors’ ambition has been to document the latest studies in this field in order to offer the readers the most comprehensive possible compendium of the state-of-the-art knowledge of these emerging contaminants. This book discusses the sources, interactions with aquatic biota and the fate of nanoscale contaminants, the developments of methods for their detection and analysis and, last but not least, the regulatory framework regarding nanoparticles (NPs) and nanomaterials in the European Union with a special focus on the hazards related to their effects on the environment.

The book starts with a general overview of the occurrence of natural and engineered nanoparticles (ENPs) and nanoplastics in different environmental compartments. It discusses the most relevant works that have proved the presence of nanopollutants in air, different water bodies and soil, and their possible uptake by living organisms, as well as highlighting the main challenges that must still be overcome. Some specific sources, discussed subsequently in detail in individual chapters, include radioactive nano- and microparticles released from Fukushima power plant and biomass burning in Southeast Asia, which greatly contribute to a nanopollutants burden in this region.

The particular exposure of the aquatic environment to nanopollutants has been widely investigated and the relevant findings are reviewed in several chapters, presenting interactions between aquatic microorganisms and metal containing NPs as well as carbon nanomaterials, such as graphene and graphene oxide NPs. A chapter is devoted to interactions of ENPs with natural organic matter and environmental compartments for which the knowledge has been very limited so far, such as porous media (e.g. soil and aquifers). A specific contribution is devoted to the bioaccumulation and characterization of the physicochemical ENP forms taken up by plants, identification of the species created following their possible dissolution, and finally, their localization within plant tissues.

The growing consciousness of the role of nanoplastics is reflected in the chapters on their effects on aquatic organisms and the role of eco-corona protein on their uptake and impact. The increasing amount of plastic waste in the environment has become a major cause of concern among the scientist community, policy makers and public opinion. The main environmental compartment concerned by discharge of plastics is water. Indeed, millions of tons of plastics end up in the oceans and freshwater reservoirs where they undergo fragmentation, mostly due to solar radiation, mechanical forces and biological action leading to smaller debris: microplastics and nanoplastics.

No meaningful conclusions on nanoparticle pollution and its effects can be drawn if carried out without reliable analytical methods, which are also required for the implementation of legislation. The analysis for NPs in the environment aims at different types of information, including their size, shape, chemical composition, number concentration and monitoring possible transformation in the environmental compartment of interest. The relevant chapters critically discuss the existing analytical techniques and methods for the analysis of nanopollutants in environmental samples, highlighting the strengths and weaknesses as well as the necessary complementarity in the choice of fit-for-purpose methods. These chapters, contributed by the leading research groups in the field, discuss sampling and pre-treatment in nanoparticle analysis in water and atmosphere as well as state-of-the-art approaches to the analysis of environmental biota. Particular attention is focused on the techniques based on the highly sensitive inductively coupled plasma mass spectrometry (ICP MS), which is able to provide valuable information on the size, size distribution and elemental composition of metal-containing NPs. Possible applications of ICP MS to the analysis of NPs in environmental compartments, including its coupling to separation systems and single-particle ICP MS, are critically evaluated together with guidelines for future developments.

The isotopic specificity of ICP MS opens up the possibility to use stable isotope labelling in the tracing of ENPs. Indeed, nanomaterials synthesized from enriched stable isotopes are chemically and physically indistinguishable from their natural equivalents, allowing studies of uptake and cycling of metal-containing NPs at environmentally realistic exposure levels. Diverse applications of stable isotope labelled nanomaterials in exposure studies as well as key advantages and characteristics of the tracing approach are reviewed.

A particular attention is focused on imaging techniques providing information on spatial quantitative distribution of elements present in NPs at the single cell level. The advantages and drawbacks related to the use of micro-proton-induced X-ray emission (μPIXE), micro-Rutherford backscattering (μRBS) and nano secondary ion mass spectrometry (nanoSIMS) are discussed, providing examples of environmental toxicology studies necessitating the sub-cellular resolution to characterize the distribution of NPs in living organisms.

The book focuses on new challenges, such as analysis of nanoplastics, which are likely to become important targets of environmental studies in the coming years. The most recent studies are critically revised and the remaining challenges to elucidate the behaviour and impact of these emerging contaminants are discussed and complemented by perspectives for future research.

The final chapter provides an overview of how European Union (EU) legislation addressing the safety of nanomaterials, including the safety of micro(nano)plastics.

We thank all the authors who contributed to this book, which we hope will become an important reference for environmental and analytical chemists, waste managers, and university students. We do hope that the joint effort of all the authors, and the information they have provided, will contribute to the growing awareness of the environmental problems related to nanopollution and development of the tools for its better understanding, control and prevention.

The editors sincerely appreciate the Royal Society of Chemistry team (especially Helen Armes and Amina Headley, and the production staff) for their availability and help in guiding us through the publication process.

Joanna Szpunar

Javier Jiménez-Lamana