Tracking Volatile Organic Compounds in Urban Wastewater Systems: A Critical Concern for Endocrine Disruptor Regulation

Wastewater treatment plants (WWTPs) are major contributors to the release of volatile organic chemicals (VOCs), many of which pose significant risks to human health through both non-carcinogenic and carcinogenic pathways. These chemicals, along with plastic-derived compounds, pesticides, and pharmaceuticals and personal care products (PPCPs), have emerged as critical environmental pollutants. Their widespread release through urban wastewater systems, combined with their hydrophilic nature and limited removal efficiency in conventional WWTPs, allows these pollutants to persist throughout the water cycle, often contaminating drinking water supplies. Despite increasing global awareness of the environmental and health risks associated with these contaminants, data on their occurrence, transport, and fate in Mexico's wastewater systems are still limited. To address this knowledge gap, the present study analyzed 54 VOCs in wastewater samples collected from 17 WWTPs across different provinces of Mexico. Among these, 38 VOCs were detected at significant levels, with the highest concentrations recorded for Toluene (21.39 µg/L), 1,1,2,2-Tetrachloroethane (28.02 µg/L), followed by p-Isopropyltoluene (27.24 µg/L), and Trichloromethane (17.56 µg/L). Additionally, pesticides and related chemicals such as 2-Chlorotoluene, Naphthalene, 1,2-Dichlorobenzene, and n-Butylbenzene were prevalent, underscoring the extensive use of these compounds in agricultural practices. These chemicals not only bioaccumulate in soil but can also leach into groundwater systems, exacerbating contamination risks and increasing their persistence in the environment. Furthermore, many of the detected compounds, such as Toluene, its derivatives, and Trichloromethane, are known endocrine disruptors (EDCs) capable of causing hormonal imbalances, drug resistance, and reduced primary productivity in ecosystems. Their bioaccumulation in organisms and persistence in water further exacerbate their environmental impact, making them critical candidates for regulatory scrutiny. Therefore, this study underscores the urgent need for enhanced regulatory monitoring and management strategies targeting VOCs and EDCs in Mexico’s wastewater systems. By providing valuable insights into the prevalence and distribution of these hazardous pollutants, the findings highlight the importance of incorporating pesticides and PPCPs into comprehensive monitoring frameworks. Such efforts are essential for mitigating the environmental and health impacts of these contaminants and ensuring the sustainable management of water resources. The results also offer a foundation for developing targeted interventions aimed at reducing pollutant loads in wastewater and preventing their long-term accumulation in aquatic ecosystems.