Association between Microplastic Exposure and Hepatic Dysfunction in Humans: A Cross-Sectional Study of Occupationally Exposed Individuals

Microplastics (MPs) are ubiquitous environmental pollutants that accumulate in human liver tissue, yet their hepatotoxicity in humans remains incompletely defined. To investigate the association between occupational MPs exposure and hepatic dysfunction in humans, we recruited 141 participants from the Health Examination Centre of Guangxi Workers’ Hospital, China, including 43 plastic-factory workers with ≥6 months of occupational exposure and 98 occupationally unexposed controls. An eight-item questionnaire-derived exposure risk score (0–8) was used to quantify MPs exposure levels. Linear and logistic regression models, adjusted for smoking, alcohol consumption, dust exposure, body mass index (BMI), and physical activity, were employed to analyze relationships between exposure (occupational status/risk score) and liver-function markers. Exposed workers exhibited higher risk scores (1.9 ± 1.1 vs 1.4 ± 0.9, P = 0.013) and twice the prevalence of abnormal liver function (48.8% vs 26.5%, P = 0.013). Each one-point increase in the risk score was associated with a significant elevation in aspartate aminotransferase (AST) by 2.82 U/L (β = 2.82, 95% CI: 0.27–5.38,P = 0.031) and total bilirubin (T-Bil) by 1.05 μmol/L (β = 1.05, 95% CI: 0.34–1.76,P = 0.004). Occupational exposure independently predicted abnormal liver function (OR = 3.97, 95% CI: 1.64–10.3, P = 0.041), with longer exposure duration linked to higher AST elevation rates. These results demonstrate that occupational MPs exposure impairs liver function, providing evidence for health-risk assessment of microplastics.