The ability to monitor the spread of diseases is essential for prevention, intervention and control practices. In this context, wastewater-based epidemiology (WBE) has been applied to empirically evaluate the exposure of populations to chemical substances and pathogens of emerging concern in near real time. During the current COVID-19 pandemic, WBE remains an innovative epidemiological tool, with the potential to complement infectious disease surveillance systems. Recent studies on WBE and COVID-19 are based on the monitoring of viral RNA fragments as target biomarkers for SARS-CoV-2 via RT-qPCR and allied techniques. Literature results have been shown the potential of WBE as an innovative tool to monitor viral spread in large communities, map contagion curves and hotspots, identify the contribution of asymptomatic individuals, and subsidize early warning systems for disease outbreaks. WBE can offer less expensive responses for monitoring large populations compared to individual clinical tests which are not feasible on large scales. This aspect is important in terms of health surveillance and associated public policies, notably where clinical tests are scarce or underestimated and in less developed regions with inadequate sanitation conditions.

Selected emerging contaminants in water samples from the Brazilian capital were investigated by liquid chromatography-mass spectrometry after solid-phase extraction. In Paranoá Lake, an urban reservoir that will be used to produce drinking water, caffeine was the most abundant contaminant found (average of 53 ng L-1), followed by atenolol (34 ng L-1), N, N -diethyl-meta -toluamide (DEET, 12 ng L-1) and atrazine (3.8 ng L-1). The role of wastewaters discharges could not be evidenced probably due to the water flow and circulation in the lake. However, higher concentrations were detected during the dry season suggesting the presence of point sources, except for atrazine. In source waters, concentrations were lower in comparison with Paranoá Lake waters. Environmental risk assessment shows the need for further surveys for atrazine. For drinking waters, only caffeine and atrazine were detected at average concentrations of 8.6 and 3.2 ng L-1, respectively. No risk for human health was observed.