British Study: Hot Drinks Contain the Highest Levels of Microplastics
London – August 28, 2025 (Qahwa World) – A peer-reviewed study from the University of Birmingham has found that everyday hot beverages—especially tea and coffee—contain the highest concentrations of microplastics among popular drinks tested, raising fresh questions about packaging, preparation practices, and real-world exposure. The paper, published in Science of the Total Environment, analysed 155 widely available drinks sold in UK supermarkets and coffee shops and is the first to assess human exposure via total beverage intake rather than water alone.
Researchers reported microplastics in every sample. Hot tea recorded the highest average concentration at 60 ± 21 particles per litre, followed by hot coffee at 43 ± 14 particles per litre. By comparison, iced tea averaged 31 ± 7, iced coffee 37 ± 6, fruit juices 30 ± 11, energy drinks 25 ± 11, and soft drinks 17 ± 4 particles per litre. Detected particle sizes ranged from 10 to 157 μm. The study also found a statistically significant difference between hot and cold beverages, indicating that temperature enhances the leaching of microplastics from packaging into drinks.
Packaging emerged as a critical factor. The authors highlight that higher temperatures increase microplastic release from packaging and that plastic packaging contributes to the contamination observed in beverages. In hot coffee served in disposable paper cups with polypropylene (PP) caps, PP microplastics predominated—strong evidence that cup materials are a primary source. Similar packaging-linked patterns appeared for iced products sold in PET bottles.
Beyond quantifying contamination, the study models realistic exposure by combining laboratory results with a survey of UK adults’ daily drink consumption. The estimated daily intake via total beverage consumption averages 1.6–1.7 microplastic particles per kilogram of body weight per day for men and women, respectively—a materially higher figure than previous estimates based on water alone. The authors conclude that focusing exposure assessments solely on tap or bottled water underestimates total intake because other beverages contribute substantially.
Contextualising these results, the research team notes that prior work by the same group measured broadly similar microplastic levels in UK tap and bottled water, underscoring that the higher counts now seen in hot tea and coffee represent an additional exposure pathway. The paper also synthesises evidence from multiple countries showing packaging and handling as recurring factors—ranging from release from tea bags to particles in soft drinks—while emphasising the novelty of testing a broad range of hot and cold beverages from a single market and pairing those measurements with consumption data.
Mechanistically, the findings are consistent: heat accelerates the transfer of particles from polymer-lined cups and lids, while materials such as PP, PET, polystyrene, polyethylene, and others appear across drink categories, mirroring common packaging choices. The authors cite previous studies that similarly link high temperature to increased microplastic release and demonstrate that both container material and product format (for example, single-use cups or PET bottles) shape the polymer “fingerprint” detected in the drink.
Public-health implications, while still being delineated by the broader scientific community, are clear enough to prompt the study’s call for more comprehensive risk assessments and policy responses. The authors characterise this work as a critical step toward understanding real-life exposure and urge regulators and industry to consider the combined effects of packaging materials, preparation conditions, and consumption habits when setting guidelines to limit human exposure.
The Birmingham team underscores limitations that likely make their exposure estimates conservative. Analytical methods in this study quantified particles ≥10 μm; smaller microplastics and nanoplastics—potentially more bioavailable—were outside detection limits. Nevertheless, with microplastics present across all categories tested and highest in hot beverages integral to daily routines, the evidence base now more firmly indicates that the act of making and serving hot drinks in common packaging can materially influence what ends up in the cup.
For consumers and producers alike, the study’s takeaway is practical: materials and temperature matter. For policymakers, the message is systemic: exposure assessments built solely on drinking water do not reflect the way people actually consume liquids. As the authors conclude, more accurate, comprehensive, and realistic exposure studies are needed to support effective environmental and public-health interventions.
Source: University of Birmingham, “Synthetic microplastics in hot and cold beverages from the UK market: Comprehensive assessment of human exposure via total beverage intake,” Science of the Total Environment 996 (2025) 180188.
