Ecohydrological assessment of the water balance of the world's highest elevation tropical forest (Polylepis).

Polylepis trees grow at elevations above the continuous tree line (3000-5000 m a.s.l.) across the Andes. They tolerate extreme environmental conditions, making them sensitive bioindicators of global climate change. Therefore, investigating their ecohydrological role is key to understanding how the water cycle of Andean headwaters could be affected by predicted changes in environmental conditions, as well as ongoing Polylepis reforestation initiatives in the region. We estimate, for the first time, the annual water balance of a mature Polylepis forest (Polylepis reticulata) catchment (3780 m a.s.l.) located in the south Ecuadorian páramo using a unique set of field ecohydrological measurements including gross rainfall, throughfall, streamflow, and xylem sap flow in combination with the characterization of forest and soil features. We also compare the forest water balance with that of a tussock grass (Calamagrostis intermedia) catchment, the dominant páramo vegetation. Annual gross rainfall during the study period (April 2019-March 2020) was 1290.6 mm yr-1. Throughfall in the Polylepis forest represented 61.2 % of annual gross rainfall. Streamflow was the main component of the water balance of the forested site (59.6 %), while its change in soil water storage was negligible (<1 %). Forest evapotranspiration was 54.0 %, with evaporation from canopy interception (38.8 %) more than twice as high as transpiration (15.1 %). The error in the annual water balance of the Polylepis catchment was small (<15 %), providing confidence in the measurements and assumptions used to estimate its components. In comparison, streamflow and evapotranspiration at the grassland site accounted for 63.7 and 36.0 % of the water balance, respectively. Although evapotranspiration was larger in the forest catchment, its water yield was only marginally reduced (<4 %) in relation to the grassland catchment. The substantially higher soil organic matter content in the forest site (47.6 %) compared to the grassland site (31.8 %) suggests that even though Polylepis forests do not impair the hydrological function of high-Andean catchments, their presence contributes to carbon storage in the litter layer of the forest and the underlying soil. These findings provide key insights into the vegetation-water­carbon nexus in high Andean ecosystems, which can serve as a basis for future ecohydrological studies and improved management of páramo natural resources considering changes in land use and global climate.

Climate and land management accelerate the Brazilian water cycle.

Increasing floods and droughts are raising concerns of an accelerating water cycle, however, the relative contributions to streamflow changes from climate and land management have not been assessed at the continental scale. We analyze streamflow data in major South American tropical river basins and show that water use and deforestation have amplified climate change effects on streamflow extremes over the past four decades. Drying (fewer floods and more droughts) is aligned with decreasing rainfall and increasing water use in agricultural zones and occurs in 42% of the study area. Acceleration (both more severe floods and droughts) is related to more extreme rainfall and deforestation and occurs in 29% of the study area, including southern Amazonia. The regionally accelerating water cycle may have adverse global impacts on carbon sequestration and food security.

Niche partitioning of two piscivorous fish species in a river in the western brazilian amazon / Particionamento de nicho de duas espécies de peixes piscívoros em um rio na amazônia ocidental brasileira

We analyzed the seasonal variation in the diet, trophic niche breadth (Levins index), the partitioning of food resources (Pianka's symmetric index) and trophic level (weighed average of trophic level of each prey determined in FishBase and SeaLifeBase platform) of Plagioscion squamosissimus (Heckel, 1840) and Hydrolycus scomberoides (Cuvier, 1819) in the Machado River, Rondônia, Brazil. Fish samplings were conducted bimonthly from June 2013 to May 2015 in five sites, using eight sets of gillnets. The occurrence frequency and volumetric frequency were used to quantify the food items. We analyzed the stomach contents of 283 individuals, 134 of H. scomberoides and 149 of P. squamosissimus. Fish were the most consumed food item by both piscivorous species. However, H. scomberoides mostly ingested pelagic fish (e.g. Characiformes fishes and Prochilodus nigricas Spix & Agassiz, 1829), while P. squamosissimus mostly consumed benthic fish [e.g. Pimelodus blochii Valenciennes, 1840 and Tenellus trimaculatus (Boulenger, 1898)]. Hydrolycus scomberoides presented the trophic level 3.55 for both periods analyzed, while P. squamosissimus 4.01 in the flood period and 3.82 in the drought period. Seasonal variations in the diet of H. scomberoides and P. squamosissimus were observed (PERMANOVA). Specifically, P. squamosissimus consumed mainly "Siluriformes" fishes and P. blochii in the drought period. The trophic niche breadth of P. squamosissimus was greater than that of H. scomberoides in the flood period. The species P. squamosissimus and H. scomberoides had low (0.35) food niche overlap in both seasons analysed. The data indicated that P. squamosissimus has a generalist feeding habit, while H. scomberoides is specialized in prey selection. The overlap of food niche between the species in both periods of the hydrological cycle was low, indicating that niche partitioning was probably the main mechanism of coexistence of these species, with little relationship with variations of the hydrological cycle.

Nós analisamos a variação sazonal na dieta, a amplitude do nicho trófico (Índice de Levins), a partição dos recursos alimentares (Índice simétrico de Pianka) e o nível trófico (média do nível trófico de cada presa determinada pela plataforma FishBase e SeaLifeBase) de Plagioscion squamosissimus (Heckel, 1840) e Hydrolycus scomberoides (Cuvier, 1819) no rio Machado, Rondônia, Brasil. As amostragens de peixes foram realizadas bimestralmente de junho de 2013 a maio de 2015 em cinco locais, utilizando oito conjuntos de redes de emalhar. A frequência de ocorrência e a frequência volumétrica foram utilizados para quantificar os itens alimentares. Analisamos o conteúdo estomacal de 283 indivíduos, 134 de H. scomberoides e 149 de P. squamosissimus. Peixes foram o item alimentar mais consumido pelas duas espécies piscívoras. No entanto, H. scomberoides ingeriu principalmente peixes pelágicos (ex. peixes Characiformes e Prochilodus nigricas Spix & Agassiz, 1829), enquanto P. squamosissimus consumiu principalmente peixes bentônicos [ex. Pimelodus blochii Valenciennes, 1840 e Tenellus trimaculatus (Boulenger, 1898)]. Hydrolycus scomberoides apresentou nível trófico de 3,55 para ambos os períodos analisados, enquanto para P. squamosissimus o nível trófico foi de 4,01 no período da cheia e 3,82 no período de seca. Variações sazonais na dieta de H. scomberoides e P. squamosissimus foram observadas (PERMANOVA). Especificamente, P. squamosissimus consumiu principalmente peixes "Siluriformes" e P. blochii no período de seca. A largura do nicho trófico de P. squamosissimus foi maior que a de H. scomberoides no período da cheia. Plagioscion squamosissimus e H. scomberoides apresentaram baixa (0,35) sobreposição de nicho alimentar nas duas estações analisadas. Os dados indicaram que P. squamosissimus tem hábito alimentar generalista, enquanto H. scomberoides é especializado na seleção de presas. A sobreposição de nicho alimentar entre as espécies em ambos os períodos do ciclo hidrológico foi baixa, indicando que a partição de nicho foi provavelmente o principal mecanismo de coexistência dessas espécies, com pouca relação com as variações do ciclo hidrológico.

Flower consumption, ambient temperature and rainfall modulate drinking behavior in a folivorous-frugivorous arboreal mammal.

Water is vital for the survival of any species because of its key role in most physiological processes. However, little is known about the non-food-related water sources exploited by arboreal mammals, the seasonality of their drinking behavior and its potential drivers, including diet composition, temperature, and rainfall. We investigated this subject in 14 wild groups of brown howler monkeys (Alouatta guariba clamitans) inhabiting small, medium, and large Atlantic Forest fragments in southern Brazil. We found a wide variation in the mean rate of drinking among groups (range = 0-16 records/day). Streams (44% of 1,258 records) and treeholes (26%) were the major types of water sources, followed by bromeliads in the canopy (16%), pools (11%), and rivers (3%). The type of source influenced whether howlers used a hand to access the water or not. Drinking tended to be evenly distributed throughout the year, except for a slightly lower number of records in the spring than in the other seasons, but it was unevenly distributed during the day. It increased in the afternoon in all groups, particularly during temperature peaks around 15:00 and 17:00. We found via generalized linear mixed modelling that the daily frequency of drinking was mainly influenced negatively by flower consumption and positively by weekly rainfall and ambient temperature, whereas fragment size and the consumption of fruit and leaves played negligible roles. Overall, we confirm the importance of preformed water in flowers to satisfy the howler's water needs, whereas the influence of the climatic variables is compatible with the 'thermoregulation/dehydration-avoiding hypothesis'. In sum, we found that irrespective of habitat characteristics, brown howlers seem to seek a positive water balance by complementing the water present in the diet with drinking water, even when it is associated with a high predation risk in terrestrial sources.

Vegetation forcing modulates global land monsoon and water resources in a CO2-enriched climate.

The global monsoon is characterised by transitions between pronounced dry and wet seasons, affecting food security for two-thirds of the world's population. Rising atmospheric CO2 influences the terrestrial hydrological cycle through climate-radiative and vegetation-physiological forcings. How these two forcings affect the seasonal intensity and characteristics of monsoonal precipitation and runoff is poorly understood. Here we use four Earth System Models to show that in a CO2-enriched climate, radiative forcing changes drive annual precipitation increases for most monsoon regions. Further, vegetation feedbacks substantially affect annual precipitation in North and South America and Australia monsoon regions. In the dry season, runoff increases over most monsoon regions, due to stomatal closure-driven evapotranspiration reductions and associated atmospheric circulation change. Our results imply that flood risks may amplify in the wet season. However, the lengthening of the monsoon rainfall season and reduced evapotranspiration will shorten the water resources scarcity period for most monsoon regions.

Application of hydrogeochemistry and isotopic characterization for the assessment of recharge in a volcanic aquifer in the eastern region of central Costa Rica.

In the eastern region of central Costa Rica, land use in the sub-basins of the Maravilla-Chiz and Quebrada Honda rivers (47 km2) is dominated by agricultural and livestock production, while groundwater resources constitute the main drinking water supply. This study aimed to (a) evaluate the location of groundwater recharge areas and groundwater flow paths, and (b) provide a characterization of the hydrochemistry and possible anthropic impacts. Groundwater was collected from 20 sites during the dry and rainy seasons and analysed for major ions, water stable isotopes and 222Rn. Approximated recharge areas were estimated through a local altitudinal line based on isotopic compositions in springs. The hydrochemical and isotopic characterization of groundwater showed that the main recharge areas occur in the upper part of the basin, except for springs in the middle part of the basin probably due to a certain hydraulic disconnection from the upper part that facilitates local recharge processes. In the lower basin, groundwater exhibited greater transit times and longer flow paths. Low nitrate, chloride and sulphate concentrations found in groundwater indicate low leaching of fertilizers or urban wastewaters. Our results are focused to improve water resources and agricultural management plans in a dynamic tropical landscape.

Use of environmental isotopes to assess groundwater pollution caused by agricultural activities.

This work applied environmental isotope techniques to validate the results of previous studies on recharge sources in a rural area in central Chile (34.3° S and 71.3° W) and discern the origin of nitrate contamination in wells. Stream water and groundwater samples were taken during three surveys, two during spring snowmelt and one in low-water conditions. Chemical analyses included major cations and anions, isotope analyses included 18O-H2O; 2H-H20; 3H-H20; 18O-NO3 - and 15N-NO3 -. The stable isotope data show that surface water and deep groundwater present depleted isotope values associated with recharge from the Andes Mountains and that shallow groundwater has more enriched isotope values that reflect the contribution of local recharge from rainwater infiltration. Depleted isotope values observed in shallow groundwater show the effect of recirculated river water used for irrigation. These results are consistent with the conceptual groundwater model developed in previous studies. Some wells have nitrate concentrations above the allowable limit for drinking water. The stable nitrogen isotopes indicate that nitrate is associated mainly with urea and ammoniacal fertilizers, and nitrate is attenuated by denitrification. The results of this study are relevant to improving management of groundwater resources used for drinking water.

Using isotope data to characterize and date groundwater in the southern sector of the Guaraní Aquifer System.

The Guaraní Aquifer System (SAG) is the largest transboundary aquifer in Latin America, extending beneath parts of Brazil, Paraguay, Argentina, and Uruguay. This paper presents the results of recent hydrogeological studies in the southern portion of the SAG. Locally, the abundance of surface water bodies precluded the use of conventional hydrological tools to characterize groundwater flows. Geological, hydrochemical and environmental isotope investigations were integrated to postulate a revised hydrogeological conceptual model. The revised geological model has provided a better definition of the geometry of the aquifer units and outlined the relevance of regional faults in controlling flow patterns. The new potentiometric map is consistent with groundwater flow from the SAG outcrops to the centre of the Corrientes Province, where upwards flows were identified. Hydrochemical and isotope data confirmed the widespread occurrence of mixing. Noble gas isotopes dissolved in groundwater (4He and 81Kr/Kr) provided residence times ranging from recent recharge up to 770 ± 130 ka. Groundwater age modelling confirmed the role of the geological structures in controlling groundwater flow. The southern sector of the SAG is a multilayer aquifer system with vertical flows and deep regional discharge near the Esteros del Iberá wetland area and along the Paraná and Uruguay rivers.

Atmospheric constraints on δ18O and d-excess in precipitation at the middle latitude in the southwestern Atlantic region.

The mid-latitude coastal area at the western South-Atlantic out of the tropics is under the combined effect of different atmospheric circulation patterns at different temporal scales, which can be shown by the isotope composition of precipitation. This pattern effect is more changing and complex than that for the well-studied tropical areas, the isotope studies being an interesting proxy for identifying major processes. This study is focused on the isotope composition of precipitation at a mid-latitude zone, in the western South-Atlantic coastal area of Argentina. δ18O and d-excess were analysed in a data series of 14 years, obtained from the integration of three neighbouring rain collectors at 38°S. A seasonality is observed in both parameters, but with some differences in the extreme months. δ18O showed a seasonality according to the temperature effect, but with a displacement of high values to spring months. Significant linear links between δ18O and Southern Annular Mode (SAM) index and Southern Oscillation Index (SOI) were recognised for the summer and spring seasons, respectively.

Isotopic insights on continental water sources and transport in the mountains and plains of Southern South America.

Hosting the flattest sedimentary plains and highest Andean range of the continent, southern South America faces hydrological transformations driven by climate and land use changes. Although water stable isotopes can help understand these transformations, regional synthesis on their composition is lacking. We compiled for the first time a dataset of H and O isotopic composition for 1659 samples (precipitation, rivers, groundwater and lakes) along latitude (22.4°S to 41.6°S), longitude (55.3°W to 71.5°W), elevation (1-4700 m) and precipitation (∼50 to ∼1500 mm/a) gradients encompassing the Chaco-Espinal-Pampas plains, their adjacent Andean Cordillera and smaller mountain ranges in-between. Emerging patterns reveal (i) only slight seasonal isotope trends in precipitation with no effects of event size, (ii) Atlantic/Amazonian vs. Pacific moisture supply to rivers north and south of the 'arid diagonal' of the continent, respectively, (iii) uniform isotopic composition in Atlantic/Amazonian-fed rivers vs. poleward isotope enrichment in Pacific-fed rivers caused by the elevation decline of the Andes, (iv) strong direct evaporation effect in rivers and shallow (<1 m) phreatic groundwater of the plains. We provide the first integrated water isotope geographical patterns of southern South America helping to improve our understanding of its water cycling patterns at the atmosphere and the land.

Identifying groundwater end members by spatio-temporal isotopic and hydrogeochemical records.

Intensive groundwater use has altered the local hydrological cycle within the Bajío Guanajuatense, Mexico. To improve the knowledge of this hydrogeological system and support water management in the area, groundwater end members were identified using multivariate statistical analysis. Pumped groundwater is composed of two well-mixed end members: (a) recent recharge, affected by a reuse cycle through irrigation where nitrate and chloride evolve and reach levels of 368 mg/L and greater than 100 mg/L, respectively, and (b) deep old groundwater. Mixing estimations show that most wells extract at least 70% of deep groundwater, and some of them extract more than 94%, posing a development and groundwater sustainability conundrum in the area.

Multi-isotope (δ 2H, δ 18O, δ 13C-TDIC, δ 18O-TDIC, 87Sr/86Sr) and hydrochemical study on fractured-karstic and detritic shallow aquifers in the Pampean region, Argentina.

Fluxes between fractured-karstified and detritic aquifers are commonly poorly understood in many environments. These two types of aquifers are in contact in the southeastern Pampean region in the Argentine Buenos Aires province, and the aim of this work is to analyze their relationship contributing to improve the hydrological model. A joint application of hydrochemical and multi-isotope (δ 2H, δ 18O, δ 13C-TDIC, δ 18O-TDIC, 87Sr/86Sr) tools was used. TDIC, δ 2H, δ 18O and δ 13C-TDIC allowed differentiating two main end members. Water in the Pampeano aquifer (PA) which is transferred from the fractured-karstic aquifer (F-KA) is characterised by high TDIC around 500-700 mg/L, isotopically depleted in 18O (about -5.5 ‰) and high δ 13C-TDIC (around -10.0 ‰). The other end member is direct recharge water infiltrated into the PA with TDIC ranging from 400 to 500 mg/L, slightly enriched in 18O (δ 18O = -4.8 ‰), and δ 13C-TDIC in the range of soil CO2 as a result of reactions with calcrete concretions (from -20.0 to -9.0 ‰). Dolomite dissolution is the main process controlling the chemistry of the low-mineralized (Mg-Ca-HCO3) waters, whereas high-mineralized (Na-HCO3) waters are strongly influenced by ion-exchange reactions with adsorbed Ca2+ and Mg2+ and by evaporation.

From mountains to cities: a novel isotope hydrological assessment of a tropical water distribution system.

Water use by anthropogenic activities in the face of climate change invokes a better understanding of headwater sources and lowland urban water allocations. Here, we constrained a Bayesian mixing model with stable isotope data (2018-2019) in rainfall (N = 704), spring water (N = 96), and surface water (N = 94) with seasonal isotope sampling (wet and dry seasons) of an urban aqueduct (N = 215) in the Central Valley of Costa Rica. Low δ 18O rainfall compositions corresponded to the western boundary of the study area, whereas high values were reported to the northeastern limit, reflecting the influence of moisture transport from the Caribbean domain coupled with strong orographic effects over the Pacific slope. The latter is well-depicted in the relative rainfall contributions (west versus east) in two headwater systems: (a) spring (68.7 ± 3.4 %, west domain) and (b) stream (55.8 ± 3.9 %, east domain). The aqueduct exhibited a spatial predominance of spring water and surface water during a normal wet season (78.7 %), whereas deep groundwater and spring water were fundamental sources for the aqueduct in the dry season (69.4 %). Our tracer-based methodology can help improve aqueduct management practices in changing climate, including optimal water allocation and reduced evaporative losses in the dry season.

Water exchange processes estimation in a temperate shallow lake based on water stable isotope analysis.

The estimation of lake hydrological characteristics such as evaporation/inflow ratios and water residence time becomes necessary for understanding cycling and potential retention of natural and anthropogenic substances into the lake. The aim of this work was to estimate the evaporation loss and the water residence time of a temperate shallow lake based on the water isotope mass balance approach. One representative freshwater temperate shallow lake from the Argentinian Pampa Plain was selected. Groundwater, lake and stream samples (N = 56) were collected for δ 2H-H2O and δ 18O-H2O determinations. Moreover, water level fluctuations of the lake and its inflow stream were recorded with data loggers. Both the δ 2H and δ 18O relationship and d-excess of lake water indicated evaporation. Water isotopes and daily stream flow data recorded in the inflow stream evidenced groundwater contribution to Los Padres Stream. Monthly evaporation as a fraction of inflow estimations of the lake water indicated that about 20-25 ± 12% lake water was lost through lake surface evaporation and revealed that hydrologic balances were regulated mainly by changes in water inflow rather than evaporation. A mean residence time of 1.11 ± 0.65 year was also calculated. This lake hydrological information is relevant for the region and crucial to improve water management plans.

First snow, glacier and groundwater contribution quantification in the upper Mendoza River basin using stable water isotopes.

The Mendoza River streamflow, South America (∼32 °S), derives almost exclusively from winter snow precipitation falling in the Andes. Almost 70% of the water feeding the river originates in the Cordillera Principal geological province. In addition to the snow that precipitates in this area, there are 951 cryoforms providing meltwater to the upper catchment. Given the high inter-annual variability of snowfall and the megadrought affecting the region since 2010, it is crucial to quantify the contribution from different water sources buffering the Mendoza River runoff. Combining instrumental records of streamflow from glaciers and rivers, meteorological data, remote sensing of snow-covered areas and ionic and stable isotope analysis of different water sources, this study attempts to understand the hydrological contribution of different water sources to the basin. We demonstrated for the first time the relevance of different water sources in addition to snow in a dry period. During the melting season, 65% of the streamwaters originated from the glaciers (i.e. 50 and 15% from glaciers and rock glaciers, respectively), representing a higher proportion compared to snowmelt (17%). Groundwater input showed relatively large contributions, averaging 18%. This work offers information to develop adaptation strategies for future climate change scenarios in the region.

Geochemical evolution, residence times and recharge conditions of the multilayered Tubarão aquifer system (State of São Paulo - Brazil) as indicated by hydrochemical, stable isotope and 14C data.

The Tubarão aquifer system constitutes a very complex, multilayered aquifer enclosed in the Paraná basin (central-southern part of Brazil). Despite the relatively low productivity of wells, groundwater represents an important source of water for the very populated and industrialized zones of the State of São Paulo. An extensive water sampling campaign was carried out followed by hydrochemical and isotopic (δ 2H, δ 18O, δ 13C and 14C) studies, aiming at a better understanding of the aquifer's geochemical evolution, recharge processes, and its groundwater residence times. Two main hydrochemical facies were recognized and divide the aquifer in two portions. The shallow portion - the active hydrological zone of the aquifer - is characterized by the Ca-HCO3 water type, evolving as a system open to atmospheric CO2. Mean residence times are typically lower than 5000 years. The lower portion is mostly characterized by the stagnant, Na-HCO3 water type, evolving under closed system conditions. Residence times average up to 15,000 years, but can reach 44,000 years, which indicates the exploitation of (possibly non-renewable) fossil waters. This study contributes to the establishment of proper policies regarding the sustainable groundwater exploitation of the Tubarão aquifer system.

Seasonal oxygen isotope variations in freshwater bivalve shells as recorders of Amazonian rivers hydrogeochemistry.

Freshwater bivalve shell oxygen isotope values (δ18OS) may act as a recorder of river δ18O variations that can then be interpreted in terms of hydrology (e.g. precipitation-evaporation balance, precipitation and river discharge patterns). We investigated the potential of this proxy measured across the hinge of South American unionid shells: Anodontites elongatus collected in Peru and A. trapesialis in Brazil. The isotopic signatures were reproducible between individuals of the same species. A. trapesialis clearly showed a strong δ18OS cyclicity in accordance with its growth patterns while A. elongatus presented less clear δ18OS with lower amplitude. We confirm that the deposition of successive growth lines and increments is annual, with growth line corresponding to the wet season. Also, we suggest that low amplitude of δ18OS in the A. elongatus shells indicates a habitat close to the river while large amplitude of δ18OS cycles observed in A. trapesialis shells would reflect a floodplain lake habitat, seasonally disconnected from the river and thus subjected to higher seasonal fluctuations in water δ18O. Considering these promising first results, future studies could be directed towards the use of fossil shells to reconstruct the past and present hydrological and geochemical conditions of the Amazon.

Global scanning of selective serotonin reuptake inhibitors: occurrence, wastewater treatment and hazards in aquatic systems.

As the global population becomes more concentrated in urban areas, resource consumption, including access to pharmaceuticals, is increasing and chemical use is also increasingly concentrated. Unfortunately, implementation of waste management systems and wastewater treatment infrastructure is not yet meeting these global megatrends. Herein, pharmaceuticals are indicators of an urbanizing water cycle; antidepressants are among the most commonly studied classes of these contaminants of emerging concern. In the present study, we performed a unique global hazard assessment of selective serotonin reuptake inhibitors (SSRIs) in water matrices across geographic regions and for common wastewater treatment technologies. SSRIs in the environment have primarily been reported from Europe (50%) followed by North America (38%) and Asia-Pacific (10%). Minimal to no monitoring data exists for many developing regions of the world, including Africa and South America. From probabilistic environmental exposure distributions, 5th and 95th percentiles for all SSRIs across all geographic regions were 2.31 and 3022.1 ng/L for influent, 5.3 and 841.6 ng/L for effluent, 0.8 and 127.7 ng/L for freshwater, and 0.5 and 22.3 ng/L for coastal and marine systems, respectively. To estimate the potential hazards of SSRIs in the aquatic environment, percent exceedances of therapeutic hazard values of specific SSRIs, without recommended safety factors, were identified within and among geographic regions. For influent sewage and wastewater effluents, sertraline exceedances were observed 49% and 29% of the time, respectively, demonstrating the need to better understand emerging water quality hazards of SSRIs in urban freshwater and coastal ecosystems. This unique global review and analysis identified regions where more monitoring is necessary, and compounds requiring toxicological attention, particularly with increasing aquatic reports of behavioral perturbations elicited by SSRIs.

Emerging pollutants in the urban water cycle in Latin America: A review of the current literature.

Emerging pollutants (EP) are increasingly studied and characterized worldwide to improve the understanding of their environmental and toxicological impacts and their occurrence and behaviors in different environmental systems. Latin America has been subject to both environmental and toxicological impacts due to EP. To better understand these impacts, studies concerning pollutants have increased for the last ten years. The current study presents a critical review on the occurrence of different emerging pollutants in various components of the urban water cycle (UWC) in Latin America. The review is based on studies performed in 11 different countries between 1999 and 2018. The countries where the higher number of investigations were conducted are Brazil (53%) and Mexico (15%). The EP most often studied within the literature are pharmaceuticals, followed by personal care products. The most common EP reported were 17ß-estradiol, bisphenol A and estrone; The UWC component with the greatest number of measurements in the reported studies were effluents from wastewater treatment plants.