As part of MiTri, reliable data on the occurrence of microplastics in the drinking water supply - especially in drinking water distribution networks - is collected in order to make a realistic exposure assessment of the intake of microplastics through drinking water consumption and to put it in relation to other intake pathways.
Microplastics (MP) have been receiving a great deal of media attention for several years now and are causing concern among the public about possible negative health consequences for humans. For this reason, MP was included by the European Union (EU) in the revised Directive (EU) 2020/2184 on ‘Quality of water intended for human consumption’. On 11 March 2024, the Delegated Decision (EU) 2024/1441 of the European Commission including the Annex - with document number C(2024) 1459 was published and has been in force since July 2024. It supplements the Directive (EU) 2020/2184 of the European Parliament and of the Council by establishing a methodology for the measurement of MP in water intended for human consumption.
The data available on the occurrence of MP in the drinking water supply is currently very limited and previous publications can only be linked to each other to a limited extent due to the lack of uniform, standardised analysis of MP until recently. As a result, no reliable statements can currently be made on the occurrence of MP in the drinking water supply - especially in the water distribution network - and it is therefore not possible to make a valid assessment of consumer exposure to MP through drinking water consumption. Initial investigations, which were carried out in accordance with the EU requirements for MP analysis, indicate that the contamination of drinking water with microplastics at the waterworks outlet is of the same order of magnitude as the analytical blank values.
The MiTri project is investigating the extent to which MP occurs in various drinking water distribution networks, depending on the materials used in the distribution network. Based on this data, an exposure estimate is made and the conditions under which quantities of MP could potentially reach the consumer at the point of transfer to the house are assessed. This estimate also takes into account the possibility that extensive sedimentation of the particles and fibres may occure in the distribution network and, in the worst case, be resuspended. Based on these findings and taking into account scientific publications on other possible uptake routes of MP in humans as well as toxicological studies, the results are classified and thus ensure the water industry's ability to speak and act vis-à-vis authorities and consumers and support the precautionary consumer protection practiced in the drinking water industry. The entire study is carried out in accordance with the requirements of the European Commission's delegated decision on the measurement of MP in water intended for human consumption.
Publications
C. S. Witzig, P. Fiener, N. Zumbülte (2024): Long-term investigation on the daily variability of microplastic concentration and composition - Monitoring in the effluent of a wastewater treatment plant, Science of the Total Environment 955, 177067. doi.org/10.1016/j.scitotenv.2024.177067
C. S. Witzig, P. Fiener, M. König, N. Zumbülte (2024): Temporal Variability of Microplastic Concentrations in Inland Waters: An Automated, Semicontinuous Sampling of Microplastics ≥ 11 μm in a Stream in Southern Germany, ACS ES&T Water 4(4), 1443-1450. doi.org/10.1021/acsestwater.3c00591
D. Schymanski, B. E. Oßmann, N. Benismail, K. Boukerma, G. Dallmann, E. von der Esch, D. Fischer, F. Fischer, D. Gilliland, K. Glas, T. Hofmann, A. Käppler, S. Lacorte, J. Marco, M. EL Rakwe, J. Weisser, C. Witzig, N. Zumbülte, N. P. Ivleva (2021): Analysis of microplastics in drinking water and other clean water samples with micro-Raman and micro-infrared spectroscopy: minimum requirements and best practice guidelines, Analytical and Bioanalytical Chemistry 413(24), 5969-5994. doi.org/10.1007/s00216-021-03498-y
M. Pittroff, Y. K. Müller, C. S. Witzig, M. Scheurer, F. R. Storck, N. Zumbülte (2021): Microplastic analysis in drinking water based on fractionated filtration sampling and Raman microspectroscopy, Environmental Science and Pollution Research 28(42), 59439-59451. doi.org/10.1007/s11356-021-12467-y
C. S. Witzig, C. Földi, K. Wörle, P. Habermehl, M. Pittroff, Y. K. Müller, T. Lauschke, P. Fiener, G. Dierkes, K. P. Freier, N. Zumbülte (2020): When Good Intentions Go Bad—False Positive Microplastic Detection Caused by Disposable Gloves, Environmental Science & Technology 54(19), 12164-12172. dx.doi.org/10.1021/acs.est.0c03742
Y. K. Müller, T. Wernicke, M. Pittroff, C. S. Witzig, F. R. Storck, J. Klinger, N. Zumbülte (2020): Microplastic analysis- are we measuring the same? Results on the first global comparative study for microplastic analysis in a water sample, Analytical and Bioanalytical Chemistry 412(3), 555-560. doi.org/10.1007/s00216-019-02311-1
