Background: Microplastics (MPs) are widely detected in drinking water, yet a comprehensive synthesis of global occurrence data with standardized health risk quantification remains lacking. This study aimed to systematically review MP contamination across drinking water source types and quantify associated human health risks. Methods: Following PRISMA ۲۰۲۰ guidelines, ۴۷ peer-reviewed studies (۲۰۱۵–۲۰۲۴) from PubMed, Scopus, Web of Science, and Google Scholar were included. Studies were coded by detection method and minimum particle-size detection limit as meta-regression moderators. Risk was assessd using Margin of Exposure (MoE = NOAEL/ADD) and Hazard Quotient (HQ) frameworks with size-stratified oral absorption fractions. Results: Pooled MP concentrations were higher in bottled water (mean = ۳۲۵ particles/L) than tap water (mean = ۴.۲ particles/L); sensitivity analysis with equivalent detection thresholds reduced this disparity from ۷۷-fold to ۱۱-fold. Polyethylene, polypropylene, and polystyrene were dominant polymers. MoE values indicated non-carcinogenic concern for bottled water-consuming adults (MoE = ۱۱) and children (MoE = ۴), both below the threshold of concern (MoE < ۱۰۰). Cancer risk exceeded ۱×۱۰⁻⁴ in high-exposure scenarios. Conclusion: Microplastic contamination in drinking water constitutes a measurable public health risk, particularly for children and bottled water consumers. Regulatory action, harmonized analytical standards, and advanced treatment technologies are urgently warranted.

کلیدواژه ها:

Microplastics ، Drinking water contamination ، Human health risk ، Environmental toxicology ، Water quality