(WHO) Report on Microplastics in Drinking Water
Total Page:16
File Type:pdf, Size:1020Kb
Microplastics in drinking-water Microplastics in drinking-water ISBN 978-92-4-151619-8 © World Health Organization 2019 Some rights reserved. This work is available under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/licenses/by-nc-sa/3.0/igo). Under the terms of this licence, you may copy, redistribute and adapt the work for non-commercial purposes, provided the work is appropriately cited, as indicated below. In any use of this work, there should be no suggestion that WHO endorses any specific organization, products or services. The use of the WHO logo is not permitted. If you adapt the work, then you must license your work under the same or equivalent Creative Commons licence. If you create a translation of this work, you should add the following disclaimer along with the suggested citation: “This translation was not created by the World Health Organization (WHO). WHO is not responsible for the content or accuracy of this translation. The original English edition shall be the binding and authentic edition”. Any mediation relating to disputes arising under the licence shall be conducted in accordance with the mediation rules of the World Intellectual Property Organization. Suggested citation. Microplastics in drinking-water. Geneva: World Health Organization; 2019. Licence: CC BY-NC-SA 3.0 IGO. Cataloguing-in-Publication (CIP) data. CIP data are available at http://apps.who.int/iris. Sales, rights and licensing. To purchase WHO publications, see http://apps.who.int/bookorders. To submit requests for commercial use and queries on rights and licensing, see http://www.who.int/about/licensing. Third-party materials. If you wish to reuse material from this work that is attributed to a third party, such as tables, figures or images, it is your responsibility to determine whether permission is needed for that reuse and to obtain permission from the copyright holder. The risk of claims resulting from infringement of any third-party-owned component in the work rests solely with the user. General disclaimers. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of WHO concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted and dashed lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by WHO in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters. All reasonable precautions have been taken by WHO to verify the information contained in this publication. However, the published material is being distributed without warranty of any kind, either expressed or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event shall WHO be liable for damages arising from its use. Design and layout by L’IV Com Sàrl Printed in Switzerland Contents Executive summary ............................................ vii Acknowledgements ............................................ xiv Acronyms and abbreviations .................................... xvii 1 Introduction ............................................... 1 1.1 Purpose of this report ..................................... 1 1.2 Scope of this report ....................................... 1 1.3 Background ............................................. 2 1.4 Overview of contents ...................................... 6 2 Occurrence of microplastics in fresh water and drinking-water ........ 8 2.1 Introduction ............................................. 8 2.2 Sources and transport of microplastics into water ................. 8 2.3 General principles of sampling and analysis ...................... 12 2.4 Overall reliability of studies ................................ 14 2.5 Microplastic concentrations reported in fresh water .............. 16 2.6 Microplastic concentrations reported in drinking-water ............ 17 2.7 Particle size, shape and polymer type in fresh water and drinking-water ....................................... 20 2.8 Other routes of exposure .................................. 20 2.9 Conclusions and research needs ............................. 24 3 Possible human health risks associated with microplastics in drinking-water: particles and chemicals ......................... 26 3.1 Introduction ............................................ 26 3.2 Potential hazards associated with particles ...................... 27 3.3 Potential hazards associated with monomers, additives and sorbed chemicals .............................................. 31 3.4 Assessing possible risks from microplastics ..................... 34 3.5 Conclusions and research needs ............................. 42 4 Possible human health risks associated with microplastics in drinking-water: biofilms ................................... 44 4.1 Introduction ............................................ 44 4.2 Characteristics of plastics and microorganisms that influence biofilm formation .............................................. 44 4.3 Potential concerns associated with microplastic-associated biofilms in water ............................................... 45 Contents iii 4.4 Distribution and risk of microplastic-associated biofilms in drinking-water .......................................... 46 4.5 Conclusions and research needs ............................. 48 5 Treatment technologies for removing microplastics from water ...... 50 5.1 Introduction ............................................ 50 5.2 Wastewater treatment .................................... 51 5.3 Drinking-water treatment .................................. 54 5.4 Considerations for drinking-water and wastewater treatment sludge .. 58 5.5 Conclusions and research needs ............................. 59 6 Managing plastic and microplastic pollution in the environment ...... 61 6.1 Benefits of managing plastic and microplastic pollution ............. 61 6.2 Responses to growing concern over plastic pollution ............. 61 6.3 Options to curb plastic and microplastic pollution ................ 62 7 Conclusions, recommendations and knowledge gaps ............... 64 7.1 Conclusions ............................................ 64 7.2 Recommendations ....................................... 68 7.3 Knowledge gaps and research needs .......................... 69 References ................................................... 71 Annex 1: Systematic review and other studies of microplastics in fresh water and drinking-water ................................. 88 A.1 Overview of systematic review .............................. 88 A.2 Systematic review methods ................................. 88 A.3 Overview of systematic review results ......................... 91 A.4 Summary of drinking-water studies ........................... 96 A.5 References ............................................ 100 Figures 1.1 Global plastic production ...................................... 5 1.2 Total non-fibre plastic production in Europe ........................ 5 2.1 Examples of routes by which plastics and microplastics enter and move in the freshwater environment and how microplastics may reach drinking-water ..................................... 12 Tables 2.1 Polymer densities ............................................ 9 2.2 Summary of reported microplastic particle numbers from freshwater studies that scored highest for quality ............................ 16 2.3 Summary of reported microplastic or microplastic-like particle numbers and particle characteristics from drinking-water studies ............... 18 iv Microplastics in drinking-water 3.1 Exposure assumptions to assess microplastic intake in drinking-water, along with rationale and associated level of conservatism .............. 37 3.2 Additional exposure assumptions to assess chemicals associated with microplastics in drinking-water, along with rationale and associated level of conservatism ......................................... 38 3.3 Upper-bound daily intake estimates of chemicals from microplastics, maximum levels of contaminants associated with microplastics, and corresponding MOE ......................................... 40 5.1 Summary of microplastic removal reported from wastewater treatment studies ........................................... 53 7.1 Summary of key hazards associated with microplastics in drinking-water and estimated health risk ...................................... 66 A.1 Overview of individual and accumulated scores from studies reporting microplastic concentrations in drinking-water, fresh water and wastewater ................................................ 92 Boxes 1.1 The risk of microplastics to aquatic ecosystems ...................... 1 2.1 Lack of sewage treatment: the bigger problem? ..................... 10 2.2 Recommendations to improve sampling and analytical methods ......... 15 2.3 Interpretation and comparison of occurrence studies ................. 17 3.1 Risk is a function of toxicity and exposure ......................... 26 5.1 Data limitations ............................................ 50 Contents v Executive summary Background Over the past few years,