Temporal and Spatial Variability of Micropollutants in a Brazilian Urban River

Metformin Contamination in Global Waters: Biotic and Abiotic Transformation, Byproduct Generation and Toxicity, and Evaluation as a Pharmaceutical Indicator

“…Specifically, the correlation shows quite a minor difference in both ρ value and significance level among different countries, such as China (ρ = 0.73, p < 0.0001, n = 215), the U.S. (ρ = 0.76, p < 0.0001, n = 19), and Vietnam (ρ = 0.76, p < 0.005, n = 13) . In addition, metformin exhibits very strong (ρ > 0.95) and highly significant ( p < 0.0001) correlations with ∑Phs at a smaller regional scale, such as the contaminated surface water of Mezquital Valley near Mexico City (ρ = 0.99, n = 11), the Paraibuna River in Minas Gerais state, Brazil (ρ = 0.97, n = 20), and urban rivers of York city, the UK (ρ = 0.96, n = 11) . Interestingly, within a single country, the correlation of metformin with ∑Phs in the urban lakes of Wuhan, China (ρ = 0.74, p < 0.001, n = 16) is consistent with that of national surface water .…”

“…This also explains why the correction between ∑Phs and metformin in the 15 Swedish effluent-impacted rivers decreases (ρ = 0.71, p < 0.0001, n = 30) compared with the values for urban rivers and nonpoint source surface water (ρ = 0.96−0.99, p < 0.0001) that are far away from point-source pollution. 25,50,78,128 Besides, caffeine shows very strong and significant correlations with ∑Phs in surface water of Mezquital valley, Mexico (ρ = 0.99, p < 0.0001, n = 11) (Figure S4), 50 which might result from the huge use of caffeine. 107 This result may explain the slightly weaker performance of metformin as an indicator of pharmaceutical contamination than that of caffeine in surface water of this city.…”

“…(D) Regional variations in the correlations of metformin with ∑Phs in the surface water of nine countries or regions. The data are adapted from published papers. ,,,,,,,,,,,− ,,,− …”

“…The correlations of carbamazepine and metformin with ∑Phs in surface water is compared in 717 global water samples to assess their performance to indicate anthropogenic pharmaceutical contamination. ,,,,,,,,,,, The correlation of carbamazepine with ∑Phs is stronger (ρ = 0.74, p < 0.0001) than that of caffeine (ρ = 0.62, p < 0.0001) but slightly weaker than that of metformin (ρ = 0.76, p < 0.0001) (Figure S10). The more ready biodegradation (45–99%), higher detection frequency (66–100%), and heavier environmental concentration (up to 1180 μg/L) of metformin than carbamazepine (<10%, 58–95%, up to 10 μg/L) seem to well favor the better performance of metformin as an indicator of human pharmaceutical contamination. ,,,,, …”

Water quality modeling in the Paraibuna River in Juiz de Fora/MG: diagnosis and prognosis

“…Cutting through the Juiz de Fora region, the Paraibuna River directly or indirectly receives untreated and partially treated wastewater from in-dustrial sectors and approximately 570,000 inhabitants. These discharges have caused pollution, contributing to an unfavorable impact on the quality of its waters (Dias et al, 2021;Quadra et al, 2021). In addition to the pollution of waters close to the urban area, water availability in Juiz de Fora has been decreasing over the last few years (Andrade and Ribeiro, 2020), and it is relative, due to the discrepancy of watercourse flows between the rain and drought seasons, which is why the Chapéu D'Uvas Dam was built in the 1990s, upstream from Juiz de Fora, to regulate the flows of the watercourse, and is currently one of the main supply sources of the city (Almeida et al, 2019;Paranaíba et al, 2021).…”