Microplastics in water, from treatment process to drinking water: analytical methods and potential health effects

Abstract

Aim: The commonly used analytical methods for microplastic (MPs) detection in drinking water and the threat of MP pollution in water intended for human consumption to human beings are presented through a systematic review. Furthermore, MP occurrence, transport, and fate from raw to treated drinking water, tap water, and bottled water, as well as the possible health impacts of MPs on human beings, are also evaluated. Methods: Systematic review included articles published in scientific journals that contain specific keywords in the title and were searched in Web of Science (WOS) and Scopus. The literature was selected and extracted by two reviewers based on the PRISMA-A guidelines, which recommend including 57 items. Results: The experimental studies pointed out that sampling is performed using grab or reduced samples, and sample treatment involves mostly oxidation with hydrogen peroxide and density separation. The minimum sample size obtainable in the extraction and the maximum density of the polymer separable from the matrix provided different results. Clearly, the determination of MPs involves the simultaneous application of several analytical techniques, including optical, fluorescence, and electronic microscopies, µFTIR, µ-Raman, and pyrolysis gas chromatography-mass spectrometry. The determination technique also provides different results according to the sensitivity as well as the minimum size determinable. These studies are mostly devoted to establishing the occurrence, transport, and fate within the supply network, the efficiency in removal of MPs from drinking water by treatment plants, and the risk to humans. The MP concentration in drinking water reservoirs is highly variable. However, tap water always presents lower concentrations of MPs than the water that enters the drinking water treatment plants because the different treatments are efficient at removing MPs. Although it has not been fully demonstrated that MPs are toxic to humans, the effects point to oxidative stress, gastrointestinal irritation, microbiome irregularities, and changes in lipid metabolism. Conclusion: Analytical methods present some common features as a first step towards harmonization. However, it is still unknown whether the analytical methods could influence the disparity of the results. The MP concentration in drinking water is low in comparison to other types of water. MPs are not exempt from hazards to human health.

A review on the presence of microplastics in environmental matrices within Southeast Asia: elucidating risk information through an analysis of microplastic characteristics such as size, shape, and type

“…Most of the studies were published from 2017 onwards, with the highest number of publications reported in 2023 at 72 articles [Figure 3]. This is also consistent with the timeline of when the term "microplastics" became very significant in the regional context due to the information from [47] . It is important to highlight that, within the context of this analysis, the inclusion of alternative keywords such as "plastic particles" was not taken into account due to their failure to adhere to the specified size parameters for microplastics.…”

“…These activities can contribute to the introduction of microplastics into aquatic ecosystems. Additionally, Southeast Asia has some of the highest rates of marine plastic pollution in the world; estimates place the combined contributions of Indonesia (10%), the Philippines (6%), Vietnam (6%), Thailand (3%), and Malaysia (3%) to the world's oceans at 30% [47][48][49] . Four different types of matrices were included in this study, comprising biota, sediment, water, and others [Supplementary Table 1].…”

Strategies to Reduce Risk and Mitigate Impacts of Disaster: Increasing Water Quality Resilience from Microplastics in the Water Supply System

“…Microplastics have been detected in water supply sources, tap water, and bottled water around the world. 8,9 Microplastics contaminate the water supply system (WSS) due to numerous reasons, including the existing social systems' policies and consumptive behaviors, and limitations in treatment. The fate and transport of microplastics through the water supply cycle (WSC) are varied, and thus the timeframes and implications also range greatly depending on the entry and exit points.…”

“…A recent study estimated that we could be ingesting cumulatively 0.1 to 5 g of microplastics a week from a combination of sources, including from drinking water which is a fundamental need for survival. Microplastics have been detected in water supply sources, tap water, and bottled water around the world. , …”

Microplastic and nanoplastic analysis in drinking water and indoor air with Raman micro-spectroscopy

“…For drinking water samples, the sample preparation may comprise vacuum filtration, digestion, and density separation, in different combinations according to the characteristics of the matrix (Picó et al 2022). Generally, the filters employed in the first step of the sample preparation are those employed during the sampling .…”