Influence of Microplastics on Environmental and Human Health

Key Considerations and Future Perspectives

Yvonne Lang, Yvonne Lang

• Publisher: CRC Press
• Year: 2022
• ISBN:
  9781000575033
• Edition: 1
• Topic: Scienze fisiche
• Subtopic: Chimica

Microplastics have received increased attention in the research world over the last ten years. A number of significant publications by the World Health Organisation, European Union, SAPEA, and GESAMP have highlighted this growing environmental and health emergency.

This book provides an accessible introduction to the microplastic problem and details its potential impact both on nature and human health. Filled with the latest developments in the field, it attempts to address the gaps in our knowledge of microplastics and also proposes additional areas of research and impact to be considered to resolve this crisis.

It will be of interest to researchers and academics working in the areas of microplastic pollution, microplastic detection, and the impact of microplastics on environmental and human health. It will also be of use to undergraduate students of environmental programmes, analytical programmes, and public health programmes.

Key Features:

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• Chapters describe the impact of our reliance on plastics in certain sectors and how they relate to microplastic pollution

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• Investigates emerging solutions to the microplastic pollution

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• Presents a multi-disciplinary perspective, covering topics such as analytical techniques, quantitative techniques, environmental monitoring, and human health monitoring

CHAPTER 1 How Do Nanoplastics and Microplastics Impact Human Health?

Yvonne Lang

Centre for Environmental Research, Innovation and Sustainability (CERIS), Institute of Technology Sligo, Ash Lane, SligoF91 YW50, Ireland

DOI: 10.1201/9781003109730-1

CONTENTS

1. 1.1 Plastic Pollution and the “War on Plastic”
2. 1.2 Evidence of Adverse Impacts of NPs and/or MPs on Human Health
3. 1.3 Future Considerations
4. References

1.1 Plastic Pollution and the “War on Plastic”

Nanoplastics (NPs) and microplastics (MPs) are plastic particles that measure less than 5 mm in any one dimension (Arthur et al, 2009; Thompson et al, 2004). The research community and policymakers have acknowledged that the scale of plastic pollution (including NPs and MPs) presents an immediate threat to environmental health and human health. Specific tasks, targets, and actions to address plastic pollution are included in The UN Sustainable Development Goals (Walker, 2021). The European Union Commission released the Strategy on Plastics in 2018 (European Commission, 2018) and the Directive on Single-Use Plastics in 2019 (European Commission, 2019) to provide a starting point to reduce plastic pollution and begin the journey towards a circular plastic economy. The result of these actions will have a positive influence in tackling NP and MP pollution.

Key reports published in 2019 and 2020 by leading scientific experts summarized current knowledge on environmental and human health risks of NPs and MPs (European Commission's Scientific Advice Mechanism, 2019; GESAMP, 2020; SAPEA, 2019; World Health Organisation, 2019). Each report reviewed available data in order to discern what was clear evidence of the impacts of NPs and MPs, and what was proposed, suggested, or speculated impacts of NPs and MPs. Overall there was a consensus across reports that due to the immaturity of the research field, and the multifaceted nature of evaluating the impact of NPs and MPs scientific knowledge “is a mix of consensus, contested knowledge, informed extrapolation, speculation, and many unknowns”(European Commission's Scientific Advice Mechanism, 2019). Currently, the literature does not provide clear and unambiguous evidence that NPs and/or MPs have an adverse effect on human health. However, it is strongly recommended that action is taken to prevent further release of these particles into the environment and to reduce and/or remove potential human health hazards.

Points raised in the reports with respect to challenges that are faced in assessing the impact of NPs and/or MPs on human health include

• lack of harmonization in the methods of assessment of exposure to NPs and MPs
• the potential that laboratory experiments do not relate to real-world exposure
• the impact of exposure to NPs and MPs on human health is influenced by the physicochemical properties of the particles, but also potential interactions of the NPs and MPs with other substances be it chemical or biologically when released into the environment

The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection identified seven key challenges to address risk assessment ranging from pathways of exposure, quantification of exposure, development of methods and technologies for monitoring and assessing exposure, upscaling effects, communication of the uncertainties and limitations, and integrating risk assessment into the policy decision process (GESAMP, 2020).

The challenges and recommendations presented by the various expert groups provide a roadmap for future directions of research in the field of NPs and/or MPs. It is time that such direction is provided as it is acknowledged that there has been an exponential growth of publications in the field of NPs and MPs. Figure 1.1 illustrates the results of a search of the Web of Science database using the keyword searches (1) “Microplastic” OR “Nanoplastic” AND “Human Health” (2) “Microplastic” OR “Nanoplastic” AND “Environment” within the period 2000–2020. Search results for January to September 2021 generate 1081 hits and 1107 hits respectively. This demonstrates the volume of work being conducted in the context of environmental and health impacts of NPs and MPs. However, it is questionable if this is being translated into growing knowledge and clear direction is needed to focus resources efficiently in tackling this global issue.

Figure 1.1 Research articles investigating the multifaceted relationship between nanoplastics and/or microplastics and environmental and human health recorded on the Web of Science Database between 2008 and 2020.

1.2 Evidence of Adverse Impacts of NPs and/or MPs on Human Health

The state of knowledge up to 2018 is summarized extensively in the SAEPA 2019 report. A number of extensive reviews published since the release of the SAEPA report have further summarized the evidence and discussed advances in knowledge (Campanale et al, 2020; Gonzalez-Acedo et al, 2021; Lehner et al, 2019; Prata et al, 2020). This section will focus on research articles published from 2018 onwards that explore NPs and/or MPs impact on human health through in vitro studies in mammalian tissue or in vivo studies in rodents or humans.

A caveat to evaluating studies is an appreciation of the fact that understanding the real threat is difficult as current studies tend to explore a particular type of plastic, while in reality exposure will be to multiple types of plastics of varying chemical composition and physical traits.

1.2.1 In Vitro Studies of NPs and/or MPs in Mammalian Cells

Table 1.1 summarizes data from cell viability studies that investigated the effects of NPs and/or MPs on mammalian cell lines. Different cell lines have been studied in order to examine the variety of potential routes of exposure. Evaluating the impact of NPs and/or MPs in vitro can be difficult as the effects of particles will be influenced by the size (Stock et al, 2021; Wang et al, 2020; Wu et al, 2019; Xu et al, 2019), shape (Stock et al, 2021), chemical composition (He et al, 2020; Stock et al, 2021), exposure time (An et al, 2021), and dose...