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.

Emerging contaminants have been considered one of the main concerns for ensuring the quality of water around the world. This work presents the results of 10 years of analyses carried out in the state of São Paulo (Brazil) that has the high population density and intense agricultural and industrial activities. In this work 58 compounds (9 hormones, 14 pharmaceuticals and personal care products, 8 industrial compounds, 17 pesticides and 10 illicit drugs) were determined from 2006 to 2015 in 708 samples including raw and treated sewage, surface and ground and drinking waters. A preliminary risk assessment for aquatic life protection identified potential risks for caffeine, paracetamol, diclofenac, 17α-ethynylestradiol, 17β-estradiol, estriol, estrone, testosterone, triclosan, 4-n-nonylphenol, bisphenol A, atrazine, azoxystrobin, carbendazim, fipronil, imidacloprid, malathion and tebuconazole. Drinking water criteria were available only for 22 compounds and for them no adverse effects were expected at the concentrations found, except for 17β-estradiol.

The distribution of consumed cocaine in the Brazilian Federal District (FD) was estimated using the wastewater-based epidemiology (WBE) approach. Sewage samples from eight wastewater treatment plants were analyzed for cocaine (COC) and benzoylecgonine (BE) using solid-phase extraction followed by liquid chromatography-mass spectrometry. The highest per capita consumption was noticed for the northern area of the Brazilian Capital (1162 mg day-1 1000 inh-1) being 32% higher than the average consumption rate of the investigated region. In this area, a day-to-day investigation revealed an average cocaine consumption of 1800 mg day-1 1000 inh-1 during the weekend, i.e., more than 50% higher than weekdays. An annual street-grade cocaine load of about 2 ton was estimated for the FD considering previous information on the actual purity of seized street drugs as well as consumers between 15 and 64 years old. Sample preservation strategies were also investigated in order to expand the WBE approach to other Brazilian areas. Sample acidification to pH 2.0 presented the smallest relative errors for COC (+11%) and BE (−4%) after a period of three days under typical transport conditions practiced by the Brazilian national postal service.

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.

Flame retardants are substances mixed with numerous materials to inhibit the combustion process, reducing risks and damages caused by fires. Among these substances, polybrominated diphenyl ethers (PBDEs) have been widely used for decades due to their low cost and high efficiency. However, since they are mixed and not chemically bonded to the materials, PBDEs can be released over time being transported through numerous pathways until they reach soils and aquatic systems, where they can accumulate in sediments and biota. Due to their high chemical stability, an essential feature for flame retardants, they are considered persistent contaminants. Several studies report the presence of PBDEs in atmospheric and aquatic particulate matter, sediments, soils and biological matrices such as marine animals, tissues and human fluids. In Brazil, little is known about the use and commercialization of PBDEs, as well as their levels in different environmental compartments. Thus, this review provides an overview of the origin of PBDEs in the environment as well as information inherent to the understanding of the behavior and presence of this contaminants of recent interest in different environmental compartments. Finally, the manuscript also brings state-of-the-art analytical approaches used for environmental sampling, preservation, preparation and sample analysis.

A multiresidue method was developed to estimate community drug use during two weekends of the 2014 Soccer World Cup via wastewater analyses. Five of the 16 investigated substances were detected in all eight samples. Benzoilecgonine (BE), the major cocaine metabolite, was the most abundant substance (1.9 ± 0.3 to 4.2 ± 0.2 μg L-1) followed by anhydroecgonine (AE) (1.5 ± 0.2 to 2.6 ± 0.2 μg L-1), phenacetin (PHE) (0.62 ± 0.06 to 1.3 ± 0.1 μg L-1), levamisole (LEV) (0.5 ± 0.2 to 1.23 ± 0.09 μg L-1), and cocaine (COC) (0.46 ± 0.07 to 0.8 ± 0.1 μg L-1). COC and BE levels suggested a human consumption origin for the investigated drugs. AE/BE ratios revealed a significant use of smoked crack/free base cocaine. Relationships between the adulterants PHE and LEV evidenced a higher use of crack cocaine in the South-Wing WWTP region. An estimative for cocaine use revealed slightly higher drug consumption during the Soccer World Cup weekends in comparison with a typical weekend in 2012.

Este é o primeiro trabalho que relata a ocorrência de resíduos de cocaína (COC) e benzoilecgonina (BE) em amostras coletadas em seis estações de esgoto diferentes (ETE) instaladas no Distrito Federal (DF) do Brasil. As concentrações de BE nos afluentes de esgoto foram utilizadas para calcular o consumo de cocaína (kg ano-1 por 1000 habitantes) em cada uma das regiões atendidas pelas ETE, em duas campanhas de amostragem (março e junho de 2010). Dentre as ETE estudadas, amostras provenientes de Samambaia apresentaram as maiores concentrações (de 3866 a 2477 ng L-1 de BE e 805 a 579 ng L-1 de COC) e doses por habitante (mais de 13 doses habitante-1 por ano). A extrapolação para toda a população do DF indica um consumo anual alcançando 1,0 tonelada de cocaína base livre, ou 1,1 tonelada de cloridrato de cocaína. Este trabalho também aborda a influência da forma de apresentação da cocaína (base livre ou sal cloridrato) e a integração com resultados de perfil químico na busca de estimativas mais realistas, principalmente no que se refere aos pontos de vista da criminalística e da segurança pública.

This is the first report on the occurrence of cocaine (COC) and benzoylecgonine (BE) residues in six samples collected from different wastewater treatment plants (WTP) located in the Brazilian Federal District (FD). Concentrations of BE in the influent sewage were used to calculate cocaine consumption (kg year-1 per 1000 inhabitants) for each region attended by the WTP from two sampling campaigns (March and June, 2010). Among the WTP studied, samples from Samambaia showed higher concentrations (from 3866 to 2477 ng L-1 of BE and 805 to 579 ng L-1 of COC) and doses per inhabitants (more than 13 doses inhabitant-1 per year). The extrapolation to the whole FD population points out to an annual consumption reaching 1.0 ton of free base cocaine, or 1.1 tons of cocaine hydrochloride. The work also addresses the influence of the cocaine presentation form (free base or hydrochloride) and the integration with chemical profiling results in a more realistic estimate, mainly concerning the viewpoints of forensics and law enforcement.

A solid-phase in-line extraction system for water samples containing low levels of emerging contaminants is described. The system was specially developed for large volume samples (up to 4 L) using commercial solid-phase extraction (SPE) cartridges. Four sets containing PTFE-made connectors, brass adapters and ball valves were used to fit SPE cartridges and sample bottles to a 4-port manifold attached to a 20 L carboy. A lab-made vacuum device was connected to the manifold cap. The apparatus is robust and less expensive than the typical available system. Its also provides less experimental handling, avoiding cross contamination and sample losses.

Analytical laboratories are expected to produce reliable results. Decision makers are guided in their actions (financial, legal and environmental) using analytical data provided by numerous laboratories. This work aimed to evaluate the analytical performance of Brazilian laboratories on producing trustworthy results. Nineteen laboratories, accredited and non-accredited ones, were contracted to analyze a USGS (United States Geological Survey) certified water sample for 17 chemical elements (mostly metals) without knowing the origin of the sample. Considering all the results produced, only 35% of them were valid. Three laboratories present satisfactory performances, whereas the majority showed a very poor overall performance. The outcomes of this work show the need for a more effective analytical quality program to Brazilian laboratories.

Copper speciation and behavior in different rivers located in the city of Curitiba were evaluated in this work. Sampling locations were selected to cover different levels of urbanization regarding their anthropogenic occupation and land use. Results showed that in highly-developed areas, both organic matter and dissolved sulfides were able to control copper speciation. Dissolved sulfide species were the major complexing agent in areas where dissolved oxygen levels are low. Finally, it was demonstrated that in urban areas anthropogenic factors such as sewage inputs and occupation of the drainage basin are the key aspects controlling copper dynamics and speciation in river waters.

Neste trabalho foi avaliada a influência das atividades antrópicas sobre as características da matéria orgânica dissolvida (MOD) aquática empregando-se fluorescência sincronizada (SyF). Amostras dos rios Iraí e Iguaçu foram coletadas em pontos localizados à montante e à jusante de uma região urbanizada, respectivamente, durante o inverno e o verão. A MOD das amostras foi analisada por SyF, titulada com Cu2+ e os dados gerados foram tratados com um modelo não linear em, pelo menos, cinco regiões espectrais. Os resultados mostraram que durante o verão, o período de maior pluviosidade, a MOD de ambos os rios apresentou estruturas orgânicas simples tais como aminoácidos aromáticos e/ou compostos alifáticos conjugados como constituintes majoritários, surgidos, provavelmente, a partir de fontes difusas. Durante o inverno foi possível evidenciar que o aporte de esgoto bruto a partir da região urbanizada contribuiu para o aumento de MOD fluorescente incapaz de complexar o cobre.

Anthropogenic influences on the characteristics of aquatic dissolved organic matter (DOM) were evaluated in this work using synchronous fluorescence (SyF) scan spectroscopy. Samples from the Iraí and the Iguaçu Rivers were collected during the summer and winter at points located upstream and downstream from a heavily urbanized area in Brazil, respectively. DOM from all samples was titrated with Cu2+ and monitored by SyF quenching. A 1:1 non linear model was used for data treatment in, at least, five distinct regions of the spectra. Results revealed that during the rainy summer, DOM from both rivers exhibited simple organic structures such as aromatic amino acids or conjugated aliphatics as the major constituents, probably arising from non-point sources. However, during the dry winter it became clear that raw sewage discharges arising from the urbanized area contributed to an increase of fluorescent organic matter that is unable to complex copper.

O objetivo deste trabalho foi avaliar a presença e o comportamento do Cu, Pb e Cd em águas de drenagem urbana na cidade de Curitiba, no Brasil. As amostras foram coletadas durante 21 eventos de chuva em uma avenida de tráfego médio. As concentrações dos metais foram similares àquelas descritas na literatura, seguindo a ordem Pb>Cu>>Cd. Uma estimativa da carga anual dos três metais para a Bacia do Rio Bacacheri, de 30 km², revelou valores de 1.520, 950 e 25 kg para Pb, Cu e Cd, respectivamente. O chumbo mostrou-se preferencialmente associado ao material particulado (82%), seguido do cádmio (66%) e do cobre (48%). Na fração dissolvida ficou evidenciada uma relação dos metais com a matéria orgânica dissolvida, seguindo a ordem Cu>Pb>Cd. As concentrações dos metais também variaram em função de fatores tais como o primeiro fluxo e o número de dias de estiagem que precedem um evento de chuva.

We investigate the presence and behavior of Cu, Pb, and Cd in runoff waters from a residential area located in the city of Curitiba, Brazil. Samples were collected in twenty-one stormwater events in an intermediate traffic way located in the Bacacheri watershed. Metal concentrations were similar to range values compiled worldwide and followed the order: Pb>Cu>>Cd. Unit loads were estimated to the watershed, which cover an area of 30 km², revealing values of 1520, 950, 25 kg for Pb, Cu, and Cd, respectively. Among the three metals, lead showed the greatest affinity for the suspended solids (82%) followed by Cd (66%) and Cu (48%). Meanwhile, an association of the metals with the organic matter in the dissolved phase, following the order Cu>Pb>Cd. Metal loads and behavior in urban runoff also depends on factors such as the first flush and the dry period preceding a storm event.

The efficiency of a new procedure for the digestion of natural waters, based on a microwave-activated photochemical reactor was evaluated in this work. Fluorescence spectra showed a 99% reduction in the emission of a 40 mg L-1 humic acid solution after 15 min of UV irradiation. In the presence of H2O2, only 3 min were necessary to accomplish a reduction of almost 100% in the emission and 6 min to reduce the concentration of dissolved organic carbon by 95%. The copper recovery from synthetic samples containing commercial humic acid, from soil suspensions, as well as from natural waters varied between 91.5 and 106.6%. The digestion of dissolved and unfiltered samples was successfully accomplished in 6 and 12 min, respectively. No contaminations or sample losses were observed. Results of copper speciation in natural waters showed that this metal is predominantly bound to natural ligands. Only 3-6% of the total recoverable copper is present in the labile form.