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Microplastics (MPs) and nanoplastics (NPs) constitute a newly recognized class of contaminants of emerging concern in air, soil, water and food, causing unavoidable exposure to humans and animals. Detection, identification and quantification of MPs and NPs in environmental matrices and biota is challenging due to the analytes' small size, random morphology, polymeric diversity, applied coatings and vast surface areas which attract chemical and microbial sorbates. This mini‐review explores strengths and weaknesses of analytical methods commonly used for MP and NP identification and quantification, including stereomicroscopy, SEM, Fourier transform infrared spectroscopy, Raman spectroscopy, flow cytometry and mass spectrometry techniques including matrix‐assisted laser desorption/ionization time‐of‐flight, pyrolysis gas chromatography–mass spectrometry and liquid chromatography–tandem mass spectrometry. Analytical challenges involved in precise MP/NP detection have been identified and recommendations have been provided to ensure data quality addressing common data quality concerns, including the difficulty of obtaining irrefutable proof that detected polymers originated from the sample as opposed to sample contamination during sample acquisition, sample processing and analysis. © 2021 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.

Polyvinyl alcohol (PVA) is a water-soluble plastic commercially used in laundry and dish detergent pods (LDPs) for which a complete understanding of its fate in the environment and subsequent consequences is lacking. The objective of this study was to estimate the US nationwide emissions of PVA resulting from domestic use of LDPs, corroborated by a nationwide, online consumer survey and a literature review of its fate within conventional wastewater treatment plants (WWTPs). Peer-reviewed publications focusing on the degradation of PVA in critical processes of WWTPs were shortlisted as a part of the literature review, and subsequent degradation data was extracted and applied to a model with a set of assumptions. Survey and model results estimated that approximately 17,200 ± 5000 metric ton units per year (mtu/yr) of PVA are used from LDPs in the US, with 10,500 ± 3000 mtu/yr reaching WWTPs. Literature review data, when incorporated into our model, resulted in ~61% of PVA ending up in the environment via the sludge route and ~15.7% via the aqueous phase. PVA presence in the environment, regardless of its matrix, is a threat to the ecosystem due to the potential mobilization of heavy metals and other hydrophilic contaminants.

Plastics pose ecological and human health risks, with disposable contact lenses constituting a potential high-volume pollution source. Using sales data and an online survey of lens users (n = 416) alongside laboratory and field experiments at a conventional sewage treatment plant, we determined the environmental fate and mass inventories of contact lenses in the United States. The survey results revealed that 21 ± 0.8% of lens users flush their used lenses down the drain, a loading equivalent to 44 000 ± 1700 kg y–1 of lens dry mass discharged into US wastewater. Biological treatment of wastewater did not result in a measurable loss of plastic mass (p = 0.001) and caused only very limited changes in the polymer structure, as determined by μ-Raman spectroscopy. During sewage treatment, the lenses were found to accumulate as fragments in sewage sludge, resulting in an estimated accumulation of 24 000 ± 940 kg y–1 of microplastics destined for application on US agricultural soils contained in sewage sludge. Recycling of the contact lenses and their packaging amounted to only 0.04% of the total waste volume associated with contact lens use. This is the first study to identify contact lenses and more specifically silicone hydrogels, as a previously overlooked source of plastic and microplastic pollution.

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