Human exposure to microplastics contained in food has become a significant concern owing to the increasing accumulation of microplastics in the environment. In this paper, we summarize the presence of microplastics in food and the analytical methods used for isolation and identification of microplastics. Although a large number of studies on seafood such as fish and shellfish exist, estimating the overall human exposure to microplastics via food consumption is difficult owing to the lack of studies on other food items. Analytical methods still need to be optimized for appropriate recovery of microplastics in various food matrices, rendering a quantitative comparison of different studies challenging. In addition, microplastics could be added or removed from ingredients during processing or cooking. Thus, research on processed food is crucial to estimate the contribution of food to overall human microplastic consumption and to mitigate this exposure in the future.

Microplastics (MPs) are ubiquitous in the environment, posing a threat to ecosystems and causing increasing concerns regarding their impacts on the human body through exposure. However, there has been limited research on the presence of MPs in functional foods, despite them being consumed for health improvement. This study aimed to investigate MP occurrence in various omega-3 oils and oil products in the Korean market and its relation to the source of raw material or manufacture. MPs were investigated in omega-3 capsules and raw oil, sourced from both plant-based (PB) and animal-based (AB) sources. We developed a method of direct filtration with acetone washing for collecting and characterizing MPs larger than 5 μm using micro-Raman spectroscopy. The average number of MPs by mass was found to be 1.2 ± 1.7 MPs/g for PB raw oil, 2.2 ± 1.7 MPs/g for AB raw oil, 3.5 ± 3.9 MPs/g for PB capsule oil, and 10.6 ± 8.9 MPs/g for AB capsule oil. Polypropylene and polyethylene terephthalate were the major MP species (83–95%) found in omega-3 oil. The proportions based on size range remained consistent across all groups, with a trend of being detected at higher rates as the size decreased. The results reveal that the main reason for the MP contamination of omega-3 oil is not the source of raw material but the manufacturing and packaging process.

Microplastic (MP) contamination in beverages has emerged as a growing public health concern, yet limited attention has been paid to exposure from traditional herbal medicine (HM), particularly when packaged in flexible plastic pouches. This study assessed the release and estimated daily intake (EDI) of MPs from five types of liquid HM products subjected to three thermal preparation conditions: unheated (UH), microwave-heated (MW), and hot-water bath (HWB). Particle analysis using micro-Fourier transform infrared spectroscopy (µ-FTIR) revealed that heating significantly increased MP release. The average EDI from one-pack daily intake was 0.042 particles/kg bw/day under UH, increasing to 0.077 for MW and 0.148 for HWB. The HWB condition led to a 3.5-fold increase compared to UH and a 1.9-fold increase compared to MW. Estimated annual exposure under high-consumption scenarios reached over 11,000 particles per person. Across all samples, HWB consistently resulted in the highest MP abundance, with polyethylene, polypropylene, polystyrene, and polyethylene terephthalate identified as the dominant polymer types. The detected MPs ranged mainly from 20 to 500 µm, providing context for potential ingestion exposure. Scanning electron microscopy showed clear surface degradation of the sachets after heating, including microcracks and roughened textures. These findings demonstrate that thermal treatment is a critical factor influencing MP release and subsequent oral exposure. Given the widespread use of plastic-packaged HM and the frequency of heating before consumption, our results underscore improved packaging materials, such as heat-resistant or biodegradable polymers, and standardized monitoring protocols to better protect consumers from unintended plastic ingestion.

The ubiquitous presence of microplastics (MPs) in the environment poses a threat to ecosystems and increases concerns about their exposure to the human body. However, despite being consumed for health improvement, limited research has been conducted on MPs in functional foods. This study aimed to investigate the occurrence of MPs and the relation of the source of raw material or the manufacture in various omega-3 oil in the Korean market. MPs in omega-3 capsule and raw oil, sourced from both plant-based (PB) and animal-based (AB) sources, were investigated. We developed the method by direct filtration with acetone washing and analyzed MPs greater than 5 μm using microscope-Raman spectroscopy. The average number of MPs was found to be 1.2 ± 1.7 MPs/g for PB raw oil, 2.2 ± 1.7 MPs/g for AB raw oil, 3.5 ± 3.9 MPs/g for PB capsule oil, and 10.6 ± 8.9 MPs/g for AB capsule oil. Polypropylene and polyethylene terephthalate were major specious (83-95 %) found in omega-3 oil. The ratio of size range remained consistent across all groups, with a trend of higher detection rates as the size diminished. The results reveal that the main reason of MPs contamination is not the source of raw material but the manufacturing and packaging process for omega-3 oil.

Microplastics (MPs) are increasingly recognized as an urgent global health concern, with mounting evidence linking their bioaccumulation to chronic disease risks. The liver, as a central organ for metabolic homeostasis and detoxification, is particularly sensitive to sustained MP exposure. However, the mechanisms underlying hepatic responses to polyethylene (PE), the most prevalent yet relatively understudied plastic type, remain poorly defined. By performing combined bulk and spatial transcriptomic analyses, we observed that PE resulted in hepatic dysfunction in mice fed on standard or metabolic dysfunction-associated steatohepatitis (MASH)–inducing diets, driving both globally and spatially distinct transcriptional alterations, including a nuclear receptor (NR), Ppara . Spatial transcriptomics uncovered the cell type heterogeneity and gene expression patterns masked in bulk analyses. Spatial clustering uncovered inflammatory hotspots characterized by reduced cellular diversity and distinct PE-responsive gene signatures. Among these, NR signaling emerged as a key regulatory axis, with Ppara identified as a modulator. We further demonstrated that Ppara regulates Anxa2 , a gene involved in damage response and tissue recovery, through enhancer and promoter binding. These findings offer insights into how PE disrupts hepatic homeostasis and underscores the value of spatial transcriptomics in elucidating environmental impacts on tissue organization and gene expression regulation. This study provides a molecular framework for understanding MP-associated disruption of liver pathophysiology and highlights potential targets for therapeutic intervention.