Developments in Managing Emerging Pollutants in Natural Waters: A Focus on Low- and Middle-Income Regions

Many emerging pollutants (EP) are the result of anthropogenic activities, the release of which is not often well-regulated. Examples of EPs include surfactants, flame retardants, pharmaceutical and personal care products, gasoline additives, biocides, polar pesticides, microplastics, and their degradation products. They have the potential to be transported over large distances and have been detected in natural waters such as rivers, lakes, and oceans across the world. Various EPs have been shown to be endocrine disruptors. Additionally, some of these substances such as hormones and antibiotics represent a threat to aquatic fauna. This can negatively affect the environment, for example, through a reduction in biodiversity or by altering ecosystem functions.

Globally, it is estimated that greater than 80% of all wastewater is discharged without being treated. In middle-income countries, the proportion of municipal and industrial wastewater which is treated is 38%. In lower-middle-income and low-income countries, the proportions are 28 and 8%, respectively.

Currently, EPs are not routinely included in international or national control programs, and their fate, behavior, and ecotoxicological effects are often poorly understood. In regions such as Latin America, the Caribbean, India, and Africa, this situation is more severe due to the lack of sufficient wastewater treatment facilities, the lack of regulation and control of industrial discharges, and the availability of low-cost and effective treatment technologies. Coupled together, this means that there is a higher probability of EPs being present in sources used for domestic and agricultural purposes.

This Research Topic seeks to provide relevant information on the state of natural waters in low- and middle-income countries in relation to the presence of emerging contaminants. As well as this, it aims to evaluate and call on the authorities and the general public to take actions that can reduce the introduction of these substances into aquatic systems.

The scope of this Research Topic includes, but is not limited to, the following:

• Development of wastewater treatment policies tailored to low- and middle-income regional requirements.
• Comparisons between the occurrence, quantity, and composition of emerging pollutants present in natural waters in low- and middle-income regions.
• Effectiveness of low-cost wastewater treatment methods that have recently been implemented in real-world situations.
• Case studies of low-cost water treatment schemes for removal of EPs.
• Analytical methods for monitoring polluted waters.
• Risk assessment related to EPs in the environment.

We welcome original research or review articles that address emerging pollutants and their current state of research in low- and middle-income regions.