Unveiling hidden contaminants: a systematic quantification and characterization of microplastics in hemodialysis and peritoneal dialysis fluids

Abstract

Microplastics (MPs) are an emerging environmental and biomedical concern due to their potential bioaccumulation and toxic effects. Given the extensive exposure of dialysis patients to large volumes of dialysate and water, the presence of MPs in dialysis solutions raises concerns regarding chronic exposure and systemic implications. This study systematically quantifies and characterizes MPs in hemodialysis (HD) and peritoneal dialysis (PD) fluids, investigating their sources and potential health risks. A total of 30 dialysis solution samples were analysed (revealing 36 suspect particles) using advanced spectroscopic techniques, including Fourier-transform infrared (FT-IR) spectroscopy, to identify polymer compositions. MPs predominantly fibers, were detected in all tested solutions, with polyethylene (PE), polyvinyl chloride (PVC), and ethylene-vinyl acetate (EVA) as the primary polymers. Statistical analyses confirmed significant variability in MP contamination across different dialysis fluids. Hemodialysis and peritoneal dialysis solutions show no statistically significant difference in MP concentration (HD: 0.29 ± 0.16 mp.L⁻¹, PD: 0.34 ± 0.02 mp.L⁻¹, p = 0.86). MP particles in HD solutions (1.31 ± 0.98 mm) are significantly larger than those in PD solutions (0.64 ± 0.43 mm) (p = 0.030). Despite similar MP concentrations, PD patients are estimated to be exposed to ~ 50% more MPs weekly than HD patients (9.57 ± 5.28 vs. 14.28 ± 0.84 mp. L⁻¹, p < 0.001). These findings highlight a potential, yet underrecognized, source of MP exposure in dialysis patients, necessitating further investigation into the implications of chronic MP absorption on renal function and systemic health. Regulatory policies should prioritize improved filtration techniques, alternative polymer-free materials, and stricter quality control measures to mitigate MP contamination in medical solutions. Future research should explore the long-term effects of MP exposure in dialysis-dependent individuals and refine analytical methodologies for contamination assessment.