Human health and ecological risk assessment of commonly used antibiotics in Tehran, Iran in 2022-2023: a modeling...

This investigation endeavored to assess the human health and ecological risks intrinsically associated with the environmental discharge of frequently utilized antibiotics during 2022-2023. Commonly used antibiotics (17 entities in 2022 and 18 in 2023) were designated based on sales volume metrics (> 95% cumulative threshold). Environmental releases were estimated contingent upon consumption figures, pharmacokinetic parameters, and population size. The MERLIN-Expo framework modeled environmental disposition and anthropogenic exposure. Toxicity endpoints were predicted using quantitative structure-activity relationship (QSAR) models. Human health risk and ecological risk of the antibiotics were determined in terms of hazard quotient (HQ) and risk quotient (RQacute and RQchronic), respectively. Amoxicillin, metronidazole, and azithromycin constituted the agents consumed in the greatest quantities annually. Significant increments in cephalosporin (+ 28.6%) and tetracycline (+ 35.8%) consumption manifested in 2023, concurrent with diminished penicillin utilization (-4%). All HQ and RQ values of the antibiotics were determined to be subordinate to conventionally accepted concern thresholds (HQ < 1, RQacute < 0.5, and RQchronic < 1.0). Nitrofurantoin (HQ = 6.54 × 10^- 4, 2022) and clavulanic acid (HQ = 5.51 × 10^- 4, 2023) exhibited the highest human health risks. Although human health and ecological risk of prevalent antibiotics in Tehran were appraised as subordinate to standard concern levels, elevated consumption rates precipitate continuous environmental discharge. The fact that risk quotients for some compounds reached noteworthy levels, although still well below regulatory thresholds, accentuates the imperative for sustained environmental surveillance, targeted antibiotic stewardship, and augmentation of wastewater management efficacy to mitigate potential long-term sequelae and the potential for antimicrobial resistance selection.

The online version contains supplementary material available at 10.1007/s40201-026-00985-1.