Human health risk assessment of Triclosan in water: spatial analysis of a drinking water system

Transgenerational Thyroid Hormone Disruption in Zebrafish Induced by Environmentally Relevant Concentrations of Triclosan

The use of triclosan (TCS)-containing disinfectants has become increasingly prevalent in response to the COVID-19 pandemic, leading to a heightened presence of TCS in aquatic ecosystems. Thyroid hormones (THs), which are essential for numerous developmental and metabolic processes, are structurally similar to TCS, rendering it prone to exert endocrine-disrupting effects. In this study, we demonstrate that TCS can induce thyroid hormone disruption in zebrafish, with transgenerational consequences. Zebrafish embryos were exposed to environmentally relevant concentrations of TCS (0, 1, 3, and 10 μg/L) for 30, 60, and 180 days. TCS accumulated in zebrafish over an extended period, causing significant, dose-dependent alterations in TH levels. Furthermore, TCS significantly thereby interfered with the expression of thyroid axis-related genes in the P0-F1 generations. Molecular docking further confirmed that TCS induces transgenerational thyroid effects through potentially strong interactions with thyroglobulin (TG), interfering with the normal physiological function of THs. These findings suggest that TCS at environmentally relevant concentrations can exert ecologically harmful effects by disrupting THs. A rigorous ecological assessment of TCS is recommended before promoting or substituting antimicrobial agents in future disinfection products.

Ecotoxicological risk assessment of triclosan, an emerging pollutant in a riverine and estuarine ecosystems: A comparative study

Triclosan (TCS), an antibacterial biocide, pervades water and sediment matrices globally, posing a threat to aquatic life. In densely populated cities like Mumbai, rivers and coastal bodies demand baseline TCS data for ecotoxicological assessment due to the excessive use of personal care products comprising TCS. This pioneering study compares spatiotemporal TCS variations and risks in freshwater and marine ecosystems employing multivariate analysis of physicochemical parameters. Over five months (January to May 2022), Mithi River exhibited higher TCS concentrations (water: 1.68 μg/L, sediment: 3.19 μg/kg) than Versova Creek (water: 0.49 μg/L, sediment: 0.69 μg/kg). Principal component analysis revealed positive correlations between TCS and physicochemical parameters. High-risk quotients (>1) underscore TCS threats in both water bodies. This study furnishes crucial baseline data, emphasizing the need for effective treatment plans for TCS in effluent waters released into the adjacent aquatic systems.

Ecotoxicological and human health risk assessment of triclosan antibacterial agent from municipal wastewater treatment plants

In this study, the occurrence and environmental risks related to triclosan (TCS) in the two wastewater treatment plants (WWTPs) were investigated in Isfahan, Iran. Influent and effluent samples were collected and analyzed by dispersive liquid-liquid microextraction (DLLME)-GC-MS method with derivatization. Moreover, the risk of TCS exposure was conducted for aquatic organisms (algae, crustaceans, and fishes) and humans (males and females). TCS mean concentrations in influent and effluent of WWTPs were in the range of 3.70-52.99 and 0.83-1.09 μg/L, respectively. There were also no differences in the quantity of TCS and physicochemical parameters among the two WWTPs. The mean risk quotient (RQ) for TCS was higher than 1 (in algae) with dilution factors (DFs) equal to 1 in WWTP1. Moreover, the RQ value was higher than 1 for humans based on the reference dose of MDH (RFDMDH) in WWTP1. Furthermore, TCS concentration in wastewater effluent was the influential factor in varying the risk of TCS exposure. The results of the present study showed the risk of TCS exposure from the discharge of effluent of WWTP1 was higher than WWTP2. Moreover, the results of this study may be suitable for promoting WWTP processes to completely remove micropollutants.