From shelf to stream: occurrence of parabens in personal care products and urban waters of La Plata, Argentina.

Parabens, preservatives commonly used in personal care products (PCPs), have emerged as environmental contaminants of concern due to their biological activity, water solubility, and pseudo-persistence. This study assessed the occurrence of methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP) in PCPs available on the Argentine market, as well as their distribution in surface water, suspended particulate matter (SPM), and sediments from La Plata city and the surrounding metropolitan area, Argentina. A total of 183 PCPs were analyzed in sampling campaigns conducted in 2018 and 2022. MeP and PrP were the most frequently detected compounds, with an overall decrease in detection frequency between the two campaigns, suggesting a shift toward "paraben-free" formulations. However, inconsistencies were observed between product labeling and actual paraben content. In environmental matrices, MeP and PrP were consistently detected across all campaigns, primarily in water and SPM, with maximum concentrations of 1519 ng/L and 24,610 ng/g (dry weight), respectively. Detection patterns were spatially and temporally homogeneous, indicating a continuous input from urban sources. Multivariate analysis confirmed the association of MeP and PrP with surface water and SPM and suggested limited retention in sediments. These findings highlight the need for stricter regulatory frameworks, improved labeling transparency, and the implementation of systematic monitoring programs that address both consumer products and their environmental implications. This study provides the first integrated evaluation of parabens in consumer products and urban aquatic environments in Argentina.