Microplastics (MPs) are pervasive pollutants found in environments and food, with humans experiencing continuous exposure. Polyethylene terephthalate (PET) is a major plastic contaminant detected in food and beverages. However, the chronic effects of environmentally relevant, physically abraded PET‐MPs on health, on the liver, remain elusive. This study investigates the hepatotoxicity of the PET‐MPs following long‐term exposure, with a focus on the gut–liver axis interactions and transcriptomic responses. Male mice are exposed to PET‐MPs (5 mg week ⁻¹ ) from 5 to 34 weeks of age. Environmentally mimetic PET particles are prepared by grinding plastic bottles. Prolonged exposure to MPs for 29 weeks led to increased adiposity and obesity. The mice exposed to PET‐MPs developed hepatomegaly, steatosis, and early‐stage fibrosis. Transcriptome data revealed the downregulation of genes involved in mitochondrial energy metabolism and the upregulation of lipid droplet and fibrotic pathway genes. Gut microbiota is also significantly changed, with a decrease in Bacteroides and Lachnospiraceae , which maintain gut homeostasis. Disruption of bile acid metabolism and fecal color change further indicated impairment of the gut–liver axis. These findings provide new toxicological insights and emphasize the requirement to reassess the public health risks posed by long‐term MPs ingestion.

Chlorophyll-a monitoring characterizes algal biomass but does not directly measure cyanotoxins or human exposure. We examined ecological spatial associations between chlorophyll-a and population-weighted estimates of Alzheimer’s disease (AD) and Parkinson’s disease (PD) patient counts in the Nakdong River basin, South Korea. Data for 2010–2022 combined chlorophyll-a from a nationwide 939-site monitoring network, older-adult populations, and administrative patient counts across 33,049 1 km grids. Geographically weighted regression described local associations. Higher chlorophyll-a occurred along river reaches and downstream areas; positive local coefficients were strongest in selected inland districts, including Sangju-si and Jinju-si, and weaker in metropolitan areas. Administrative sensitivity analyses showed that association direction and magnitude depended on population adjustment and model specification. Supplementary bandwidth analyses also identified scale dependence and persistent residual spatial autocorrelation. Because the grid outcomes were constructed from administrative counts, interpolation accuracy was unquantified, and source-specific clinical definitions were unverified; these findings indicate exploratory ecological covariation rather than a toxicological effect or causal risk. The mapped contrasts may guide targeted water-quality and cyanotoxin monitoring and epidemiological validation.