Science of The Total Environment

The characterization of risk due to recreational exposure to water needs to assess the concentration of pathogens in the water and the degree of contact with those pathogens. In this study we assessed the risk associated to E. coli and cyanobacteria in a large South American Reservoir heavily used for recreation, by i) gathering field environmental data from two water agencies (six sites, summers 2011-2015), ii) generating satellite data at landscape scale (750 km2, summers 2011-2017) and running a health survey related to water exposure (summer 2017). Field data showed that cyanobacteria abundances recurrently surpassed the moderate and high-risk categories across sites and year analyzed, and a significant positive link between cyanobacteria abundance and microcystin concentration. Nevertheless, microcystin concentrations were in 90% of cases mostly within the low to moderate risk categories. Mean E. coli concentrations during 2011-2015 were within the high-risk category in 30% of the sites, but in 2017, sites identified as low risk had high-risk. The latter underscores the high risk posed by E. coli in the reservoir. Cyanobacteria (cell abundance and microcystin) and coliform bacteria abundances were unrelated, suggesting different responses to environmental or anthropogenic triggers. Satellite data evidenced that the highest risk related to cyanobacteria abundance occurred in the dendritic areas of the Argentinean side of the reservoir, areas which currently remain unmonitored by water agencies. Satellite monitoring bridged the limited spatial and temporal coverage of field samplings for cyanobacteria abundance (yet not for toxicity nor E. coli abundances) and rendered a risk map at landscape scale, which can be used by water agencies to effectively monitor and manage cyanobacteria blooms, and to-coupled with exposure variables-assess health risks related to cyanobacteria. The health survey identified few numbers of suspected patients with symptoms and who bathed in the Salto Grande reservoir. At the time of exposure, sites in the environment evidenced high bacteria concentration (mostly E. coli and to a lesser extent cyanobacteria) denoting situations where aspects of the biophysical environment affect human health. More studies and integration among environmental and health disciplines are needed to assess the impacts of these water born bacteria in human health. Finally, we further assessed how well cyanobacteria quantitative proxies monitored in the field explained the outcome of a qualitative risk communication system-the cyano-traffic-light-which is ongoing since 2011. We obtained a significant predictive model only for cyanobacteria abundance, yet with low predictive value. This probably occurred because the variables used to build each cyano-traffic-light category (cyanobacteria abundance, toxicity and chlorophyll-a, scums) were monitored with different frequencies, and because at least two of these variables needed to surpass the threshold of each category to be allocated into a risk category. Based upon our results we propose several modifications to the current cyano-traffic-light, that believe would better reflect what happens in the field and protect human health: i) include E. coli concentration and satellite estimated cyanobacteria abundance (mostly in areas not covered by field monitoring), ii) relax the thresholds for cyanobacteria abundance and toxicity, and iv) base each risk category upon the surpassing of one of either E. coli, cyanobacteria abundance, microcystin.

The aquatic toxicity of tire wear particles (TWPs) depends on the leaching of various components. The leaching process is time-dependent and influenced by various environmental factors, leading to fluctuation in leachate toxicity. In this study, we quantified the temporal dynamics of leachate toxicity using the dose-response model. Meanwhile, to simulate weathering conditions, TWPs were exposed to ultraviolet (UV) irradiation and elevated temperature. The results indicated that the leachate toxicity over time fitted a biphasic pattern, with an initial increase followed by a decrease, peaking at the 11th day. The toxicity fluctuation cannot be characterized by any single component, but rather leachate should be considered as an integral whole aligning with a typical hormesis dose-response curve. High temperature of road surface increased leachate toxicity by 66%, due to elevated concentrations of 67 identified organic compounds. UV irradiation, however, mitigated this effect, acting as antagonism. These findings underline the seasonal and spatial heterogeneity in leachate toxicity. Additionally, high temperature induced the volatilization of organic compounds within TWPs, highlighting an independent exposure pathway. The methodology developed in this study will provide foundation and standard for future research on the aquatic ecotoxicity of TWPs. Environmental ImplicationThe toxicity of leachate from ubiquitous tire wear particles (TWPs) to aquatic organisms has been confirmed in field and experimental studies. However, existing researches indirectly used TWPs quantity as sole proxy for leachate toxicity, neglecting its fluctuations over leaching duration and in situ environmental factors, potentially confounding toxic effects. Herein, this study quantifies these dynamics of leachate toxicity based on measurable biological response, aiming to establish a standard scale for further quantitative assessment of TWPs ecological risk.

The identification of thermal heterogeneity in the environment and its inclusion in adaptive strategies are key to habitat management of cold-water fish, including salmonid species. This study tested the hypothesis that upwelling of groundwater (GW) from a tributary catchment through a relatively deep aquifer (tributary GW) affects salmon redds selection in an urbanized gravel-bed river, and that the spawning preference of such areas depends on the seasonal context. The field study was conducted between 2001 and 2015 in an approximately 6-km long segment of the Toyohira River, Northern Japan. Chum salmon redds distribution data over 15 years (2001-2015) were combined with spatial distribution data of hyporheic water affected by tributary GW in the riverbed to examine seasonally variable redds site selection in relation to the presence of unique GW. Furthermore, models that predicted the hyporheic water thermal regime were coupled with redds count data to estimate the approximate timing of fry emergence from the riverbed. The redds site selection was seasonally variable, with a higher dependence on tributary-GW-affected areas with a decrease in water temperature. The time until fry emergence from spawning was shortened when the tributary-GW area was chosen during the cold winter. Overall, the present study identified hotspots for salmon spawning redds in winter with a disproportionately high level of site selection because of their warmer temperature compared to surface river water in winter. Thermally diverse spawning habitats allow the diversification of spawner strains in synchronized descents to the sea. Signs of tributary-GW pollution was suggested, and thus the conservation of the groundwater pathway and its sources, followed by improvements in quality, can be beneficial to the Chum salmon populations in the Toyohira River.

BackgroundWastewater surveillance has expanded globally to monitor the spread of infectious diseases. An inherent challenge is substantial noise and bias in wastewater data due to their sampling and quantification process, leading to the limited applicability of wastewater surveillance as a monitoring tool and the difficulty. AimIn this study, we present an analytical framework for capturing the growth trend of circulating infections from wastewater data and conducting scenario analyses to guide policy decisions. MethodsWe developed a mathematical model for translating the observed SARS-CoV-2 viral load in wastewater into effective reproduction numbers. We used an extended Kalman filter to infer underlying transmissions by smoothing out observational noise. We also illustrated the impact of different countermeasures such as expanded vaccinations and non-pharmaceutical interventions on the projected number of cases using three study areas in Japan as an example. ResultsOur analyses showed an adequate fit to the data, regardless of study area and virus quantification method, and the estimated reproduction numbers derived from wastewater data were consistent with notification-based reproduction numbers. Our projections showed that a 10-20% increase in vaccination coverage or a 10% reduction in contact rate may suffice to initiate a declining trend in study areas. ConclusionOur study demonstrates how wastewater data can be used to track reproduction numbers and perform scenario modelling to inform policy decisions. The proposed framework complements conventional clinical surveillance, especially when reliable and timely epidemiological data are not available.

The contamination of non-target organisms and ecosystems by pesticides can adversely affect biodiversity and key ecosystem services such as pollination or natural pest control. In this study, we used honey bee colonies as sentinels of environmental contamination in four distinct habitats--urban, suburban, forest, and vineyard--and collected bees every three weeks from May to November. Pesticide residues were extracted using an adapted QuEChERS method and analyzed by LC-MS/MS, while inorganic elements were measured by ICP-MS and ICP-AES. Our results show that land-use and seasonal changes shape contaminant patterns in bees. Vineyards left the strongest chemical footprint on bees, as indicated by the wide diversity of contaminants detected in this environment. This reflects multiple exposure to both current and historical pesticide inputs--such as copper--which can accumulate over time to potentially harmful levels. Pollinators like honey bees provide effective indicators of environmental risk, as their health and contaminant loads can reveal broader ecological impacts. Overall, environmental exposure and local contaminant inputs determine the pollutant burdens in pollinators, which may affect honey bee health and the ecosystem services they provide.

Greenhouse gas (GHG) emissions from reservoirs are quantitatively relevant for atmospheric climatic forcing. These emissions have large temporal variability, with daily changes accounting for a substantial part of this variability. However, most estimations for GHG fluxes are based on the upscaling of discrete measurements performed during the daytime and, in general, they do not account for nighttime emissions. Here, we explored the daily patterns of CO2, N2O, and diffusive and ebullitive CH4 fluxes in two eutrophic reservoirs with contrasted morphometries in two different years. We found a daily pattern for CO2, N2O, and diffusive CH4 fluxes with consistent higher emissions during the daytime than during the nighttime, irrespectively of reservoir morphometry. These three diffusive fluxes showed evident daily synchrony suggesting a common driver. The emissions were coupled with the daily solar cycle, wind speed, and water temperature. The daily emissions of the CO2, N2O, and CH4 were also positive and significantly related to oxygen saturation. In contrast, we did not find a consistent daily pattern for the ebullitive CH4 fluxes, although they represented a significant fraction of the total CH4 emitted in these reservoirs. Our study suggests that the daily variability in GHG emissions may be as relevant as the variability at spatial scale or inter-system variability. Therefore, daily ranges should be considered in future GHG budgets to refine temporal trends of GHG emissions from reservoirs.

The recent surge of hepatitis of unknown origin in children is hypothesized to be caused by adenovirus 41 and/or SARS-CoV-2 infections. A relatively high proportion of patients testing positive for these viruses concomitantly with the development of acute hepatitis supports this hypothesis. To formally incriminate these viral infections as causative agents of hepatitis, both a plausible physiopathological pathway and supporting epidemiological dynamics in the community need demonstration. In this study, we measured the level of circulation of adenovirus 40/41 and SARS-CoV-2 in the general population of the city of Leuven in Belgium using wastewater monitoring between December 2020 and May 2022 and indoor air sampling in day care centers between November 2021 and May 2022. We also retrospectively analyzed medical records of 12.672 children attending a tertiary hospital draining the same region between January 2019 and April 2022. Our results demonstrate a recent but modest increase in hepatitis of unknown origin concomitant with a surge of circulating adenovirus 41 and SARS-CoV-2 in the general population, including in children under 5.

River ecosystems belong to the most threatened ecosystems on Earth. Historical anthropogenic alterations have, and future climate change will further affect river ecosystems and the species therein. While many studies assess the potential effects of expected future changes on species, little is known about the severity of these changes compared to historical alterations. Here, we used a unique 300-year time series of hydrological and climate data to assess the vulnerability of 48 native fish species in the upper Danube River Basin. We calculated species-specific vulnerability estimates relative to the reference period (1970-2000) for the periods 1800-1830, 1900-1930, and 2070-2100, including two Representative Concentration Pathways (RCP 4.5 and 8.5) and identified the environmental drivers of vulnerability estimates. Models showed that future changes under RCP 4.5 would result in moderate species vulnerability compared to historical conditions, while under RCP 8.5, the vulnerability for all species increased substantially. In addition, species vulnerability was mainly driven by hydrology in the past and is likely to be driven by temperature in the future. Our results show that future climate change would alter environmental conditions for riverine fish species at a similar magnitude as historical anthropogenic hydrological river alterations have. Shedding light on such long-term historical and possible future anthropogenic alterations provides valuable insights for prioritising conservation actions for riverine fish species.

Lead pollution remains a worldwide environmental and health issue with persistent detrimental effects on human and wildlife. Despite having been identified as an issue for wildlife a long time ago, the use of lead shot for hunting in wetlands was banned only in 2006 in France. Here, we took advantage of a long-term monitoring of waterfowl lead shot contamination in the Camargue (southern France) to (1) assess the local effectiveness of the French regulation in reducing waterfowl contamination and to (2) assess local compliance regarding the use of nontoxic shots in wetlands from 2007 onwards. We collected waterfowl gizzard from 38 hunters in the Camargue during 20 hunting seasons (1998 to 2017) for a total of 2306 gizzards from 28 different species. From 2008 to 2019, we also systematically collected the cartridge casings at three sites of communal wetland hunting. Ratio of lead vs nontoxic cartridges found in the field allowed monitoring hunter compliance with the new regulation. Despite a ten-year long ban on lead shot our results do not show any significant reduction in waterfowl exposure to lead through shot ingestion in the Camargue over the 20-year monitoring period. Indeed, gizzards of harvested waterfowl were as likely to contain at least one lead shot before the ban as after with a mean prevalence of 12% over the 13 species considered across the study period. Cartridge casings showed the persistence of use of lead shots by hunters in the Camargue wetlands despite a slow increase in the use of nontoxic cartridges. This unequivocally indicates that the law is far from being strictly applied, pointing to an insufficient policy enforcement. Our results support the need for a complete ban of lead ammunition for both wetland and terrestrial wildfowl which will facilitate policy enforcement and compliance.

Photosymbiosis indicates a long-term association between animals and photosynthetic organisms. It has been mainly investigated in photosymbiotic cnidarians, while other photosymbiotic associations have been largely neglected. The acoel Symsagittifera roscoffensis lives in obligatory symbiosis with the microalgal Tetraselmis convolutae and has recently emerged as alternative model to study photosymbiosis. Here, we investigated the effects of Bisphenol A, a common plastic additive, on two pivotal stages of its lifecycle: aposymbiotic juvenile development and photosymbiogenesis. Based on our results, this pollutant altered the development of the worms and their capacity to engulf algae from the environment at concentrations higher than the levels detected in seawater, yet aligning with those documented in sediments of populated areas. Data provide novel information about the effects of pollutants on photosymbiotic associations and prompt the necessity to monitor their concentrations in marine environmental matrices.

SARS-CoV-2 in infected patient mainly display pulmonary and oronasal tropism however, the presence of the virus has also been demonstrated in stools of patients and consequently in wastewater treatment plant effluents, questioning the potential risk of environmental contamination (such as seawater contamination) through inadequately treated wastewater spill-over into surface or coastal waters. The environmental detection of RNA alone does not substantiate risk of infection, and evidence of an effective transmission is not clear where empirical observations are lacking. Therefore, here, we decided to experimentally evaluate the persistence and infectious capacity of the Porcine epidemic diarrhea virus (PEDv), considered as a coronavirus representative model and SARS-CoV-2 surrogate, in the coastal environment of France. Coastal seawater was collected, sterile-filtered, and inoculated with PEDv before incubation for 0-4 weeks at four temperatures representative of those measured along the French coasts throughout the year (4, 8, 15, and 24{degrees}C). The decay rate of PEDv was determined using mathematical modeling and was used to determine the half-life of the virus along the French coast in accordance with temperatures from 2000 to 2021. We experimentally observed an inverse correlation between seawater temperature and the persistence of infectious viruses in seawater and confirm that the risk of transmission of infectious viruses from contaminated stool in wastewater to seawater during recreational practices is very limited. The present work represents a good model to assess the risk of transmission of not only SARS-CoV-2 but may also be used to model the risk of other coronaviruses, specifically enteric coronaviruses. ImportanceThis present work is a follow up addressing the question of the persistence of coronavirus in marine environment owing to the fact that SARS-CoV-2 is regularly detected in wastewater treating plan and the coastal environment is particularly at risk since it is subjected to increasing anthropogenic pressure and is the final receiver of surface waters and treated or sometimes insufficiently depurated waste waters. Our findings are of interest to researchers and authorities seeking to monitor SARS-CoV-2 and also enteric coronaviruses in the environment, either in tourist areas or in regions of the world, where centralized systems for wastewater treatment are not implemented, and more broadly, to the scientific community involved in "One Health" approaches.

Analyzing the Lime Seed Bugs (Oxycarenus lavaterae) European range expansion, optimized Maxent models and comprehensive occurrence data (2007-2025) reveal a swift northward and eastward spread, with a distinct "rapid expansion" phase starting in 2017. Key drivers include minimum and maximum temperatures, and importantly, downward shortwave radiation (DSR). Increased DSR, linked to "global brightening" from reduced air pollution since the 1990s, provides crucial thermal benefits. This enables the bugs basking behavior to effectively elevate body temperatures, mitigating cold stress and enhancing overwintering survival in newly colonized northern regions. Focusing on Ukraine and Latvia, optimal habitat is predicted in Ukrainian regions like Transcarpathia, aligning with observed occurrences, while Latvia shows minimal invasion chances. This study rigorously integrates statistical modeling (including SHAP analysis) with biological insights, demonstrating how temperature extremes and DSR act as physiological "bottlenecks" for the species successful adaptation and expansion. The findings advance understanding of insect range dynamics under climate change and regional air quality improvements, providing critical insights for biodiversity conservation and targeted pest management. Furthermore, the presented methodologies facilitate citizen science efforts for ongoing ecological monitoring, empowering broader community participation in tracking environmental responses. Continued interdisciplinary research on these climatic and anthropogenic factors is vital for refining predictive models and informing adaptive management in a changing world.

This study evaluated the impact of a desalination plants waste discharge on the adjacent marine biocoenosis in the Pelo de Oro inlet, Santa Maria Key, Cuba. The research area was divided into eight strata, and sampling was conducted in four stages to measure salinity, species richness of selected megazoobenthos, and variations in Thalassia testudinum coverage. The salinity showed no anthropogenic alterations, and three species of megazoobenthos were identified: Holothuria floridana, Echinaster sp., and Lytechinus variegatus. The abundance of L. variegatus decreased in the RSDESCARGA stratum due to the plants cleaning procedures, while the CONTROL stratum showed higher abundance and stability. No significant differences were observed in Echinaster sp. abundance across strata. H. floridana was most abundant in the RSDESCARGA stratum during the pre-start stage. The study found no evidence of brine discharge impact but provides a baseline for future comparisons as the plant reaches full operational capacity.

After the COVID-19 pandemic, wastewater monitoring is increasingly used for infectious disease surveillance. Using the data from a controlled experimental hospital setting, this paper examines the association wastewater SARS-CoV-2 with COVID-19 hospital admission and mortality, and whether this association varies by patients characteristics. Weekly wastewater samples were collected from the University of Miami (UM) hospitals where COVID-19 patients were admitted from February 2020 to October 2022, and SARS-CoV-2 was quantified using qPCR. Data on hospital admissions and their mortality and demographic characteristics and comorbidities were acquired from the UM hospitals. Using factor analysis and hierarchical clustering, patients were stratified into four clusters. Frist, we examined cross-correlations between time-lagged COVID-19 hospital admission and mortality, and time-lagged SARS-CoV-2 to identify appropriate time-lags. Second, we modelled daily hospital COVID-19 cases and mortality with respect to time-lagged SARS-CoV-2, vaccine status and time-lagged COVID-19 hospital cases (as proxy of the risk factor for the transmission of the disease for each cluster separately and for all clusters together. 1,856 COVID-19 patients were admitted in the UM hospitals during the study period and 347 (18.7%) of them died. In cluster 4 that represented patients with preexisting chronic health conditions and intubation, the fatality rate was 59%. COVID-19 hospital admission showed strong (temporal) autocorrelation, suggesting that the preexisting cases can indicate the transmission rate of infection. Our analysis suggests that a 1% increase in SARS-CoV-2 was associated with a 0.28% increase in COVID-19 related hospital admission ({beta} [~] 0.275; 95 % CI = 0.18 to 0.37; p < 0.01). Both a week lagged auto-regressive COVID-19 cases and SARS-CoV-2 in wastewater together explained 89% of the total variation in hospital admission due to COVID-19. Among four clusters, the second cluster of minority communities showed the strongest association between time-lagged SARS-CoV-2 in wastewater and hospital admissions due to COVID-19 followed by cluster 1 of adult patients with low prevalence of preexisting health conditions. However, time-lagged wastewater SARS-CoV-2 did not show any significant association with COVID-19 hospital admission for patients with the pre-existing health conditions. A week lagged wastewater SARS-CoV-2 did not show any significant association with COVID-19 mortality. Our results indicate that the association between time-lagged wastewater SARS-CoV-2 and COVID-19 hospital admission varied by patients characteristics, suggesting variations in SARS-CoV-2 shedding by patients characteristics. These findings warrant to incorporate patient-specific demographic characteristics and comorbidities in modelling infectious diseases surveillance using wastewater monitoring of the infectious agents.

BackgroundArboviral diseases, transmitted by infected arthropods, pose significant economic and societal threats. Their global distribution and prevalence have increased in recent years, driven by factors such as climate change, biodiversity loss and urbanization. These diseases are often underestimated due to uneven surveillance and asymptomatic cases. Current surveillance relies on monitoring vector occurrence and spatial distribution, as well as syndromic monitoring. In this work, we aimed to explore the utility of wastewater-based surveillance as an additional, added-value tool for vector-borne viruses tracking. MethodsA retrospective wastewater-based surveillance survey was conducted at ten wastewater treatment plants covering a large part of Portugal mainland (North, Lisboa and Vale do Tejo and South regions). Using RT-qPCR, we quantified the RNA concentrations of Dengue (DENV) and Chikungunya (CHIKV) viruses for a period of 12 months (n = 273 raw wastewater samples), ranging May 2022 - April 2023. FindingsDENV was detected in 25% of the samples, with concentrations spanning from 3{middle dot}5 to 6{middle dot}8 log copies/L. CHIKV was detectable in 11% of the samples, with concentrations up to 6{middle dot}3 log copies/L. Notably, the occurrence of DENV and CHIKV was rather similar between the three regions. The Lisboa and Vale do Tejo region exhibited in general the highest median concentration for DENV and CHIKV following normalization with crAssphage (1{middle dot}5 x 10-4 and 1{middle dot}1 x 10-3, respectively). InterpretationWe demonstrate the efficacy of wastewater-based surveillance as a potent tool for gauging the epidemiological landscape of both DENV and CHIKV in mainland Portugal, where autochthonous cases have not been detected yet. Therefore, WBS should be integrated as a supplementary component to standard surveillance strategies. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSWastewater serves as a valuable resource for wastewater-based surveillance (WBS). This surveillance method involves analyzing biomarkers of human metabolism, activities and lifestyle in wastewater to gain insights into public health trends. Previously, WBS has been employed to track chemical substances like illicit drugs, including cocaine, as well as oseltamivir during the 2009 influenza pandemic. It has also played a crucial role in the global polio eradication program by contributing to assess poliovirus circulation in populations and evaluating immunization effectiveness. During the SARS-CoV-2 pandemic, there was a significant boost in wastewater-based surveillance. To the best of our knowledge, our study represents the first extensive application of this approach to comprehensively investigate and identify the presence of vector-borne viruses RNA such as chikungunya and dengue. In December 2022, we conducted a search on PubMed and Google Scholar for publications using the search terms "wastewater" and "dengue virus" or "chikungunya virus" or "West Nile virus" or "Zika virus", encompassing manuscripts in all languages. Our search yielded only one study that focused on detecting arboviruses in wastewater, specifically Dengue. Surprisingly, the authors were unable to detect viral RNA despite the reported cases of Dengue between 2017 and 2019, when the wastewater samples were collected. This period included a major outbreak in 2019, with more than 7,000 confirmed cases. Remarkably, no other study has shed light on the presence and concentration of Dengue and Chikungunya viral RNA in wastewater. Added value of this studyIn response to the gap identified in the literature review, this study makes a significant contribution by reporting for the first time the presence and concentration of arboviral RNA, specifically focusing on the Dengue and Chikungunya viruses. Notably, it has demonstrated the circulation of these viruses, even when only a few travel-associated cases have been reported throughout the years and where no autochthonous have been reported within the community, although the vector (Aedes albopictus) has been identified in several occasions in mainland Portugal. This research underscores the vital role of wastewater-based surveillance in gaining insights into the circulation trends of underreported pathogens within communities at the sewershed level. Implications of the available informationArboviral infections are significantly underreported, especially in non-endemic countries, and they can lead from mild to severe health issues and even mortality. The symptoms are unspecific and resemble those of various other illnesses, such as Influenza and COVID-19. Consequently, many infected individuals may not seek medical assistance, and when they do, their infections might be misdiagnosed. This results in surveillance for arboviral infections being biased toward individuals presenting with unusual symptoms or severe illness, or returning from endemic regions, leading to delayed reporting and limited temporal and spatial accuracy. In contrast, wastewater surveillance provides results within 24 hours of sample collection and offers a representation of the population served by the sewer system. This includes asymptomatic individuals and those with mild symptoms who may not seek medical care. This approach increases the likelihood of detecting viral circulation and thus prompt public health intervention, namely through vector control, limiting the potential transmission to new hosts, breaking the cycle of transmission. Wastewater surveillance data can play a crucial role in informing public health and environmental decision-making. It can reveal the presence of unaccounted-for infections, indicating the need for control and mitigation strategies, both at the population and mosquito vector levels. Although the arboviral activity is assumed residual in Portugal, wastewater monitoring can be used in complement to the efforts that are already done under the National Vector Surveillance Network. Moreover, this data can be used to communicate with the general public, encouraging them to take actions that can help control the mosquito population, such as reducing stagnant water sources where mosquitoes lay their eggs. This is especially important for vulnerable populations, enabling them to make more informed decisions to mitigate the underlying risks effectively.

We characterized how land use influenced dissolved nutrients and periphytic algal biomass in an Andean basin from Northwest Patagonia. Nutrient export, especially dissolved inorganic nitrogen increased with human population density. However, no correlation between nutrient concentration and algal biomass was found, which could instead be limited by light availability. Our results suggest that local N-limited ecosystems are liable to eutrophication by increased demographic pressure and that alternative wastewater treatment strategies are necessary for sustainable growth.

Wastewater surveillance to monitor the incidence of infections faces challenges, in terms of discrepancies with sentinel-confirmed cases. We examined whether testing rates could explain the discrepancy between SARS-CoV-2 RNA found in a City of Sapporo wastewater treatment plant and the number of infections recorded at Hokkaido University Hospital over a period of approximately four years. Then, we analyzed the association between wastewater RNA concentrations with incidences of new cases among hospital-acquired infections. Linear regression analyses were performed using wastewater RNA concentrations as the independent variable and infected cases with and without correction for the testing rate as the dependent variable. In addition, modified Poisson regression analyses were performed, with the incidence of new cases among hospital-acquired infections as the dependent variable. After the legal reclassification of COVID-19 in Japan was changed to the same category as seasonal influenza, the rate of hospital testing declined significantly, though wastewater RNA concentrations remained high. Compared to non-correction for testing rates, corrected community-acquired infection cases showed a stronger association with wastewater RNA concentrations (R2 = 0.54 and 0.75, respectively). The incidence of hospital-acquired infections was positively associated with wastewater RNA concentrations (incidence risk rate: 2.24 [95% confidence interval: 1.36-3.71]), and a log10 wastewater RNA concentration [copies/L] of 4.57 (4.10-5.03) was suggested as a 25% probability of new incidence. This study emphasized that SARS-CoV-2 wastewater surveillance is an objective and useful indicator reflecting infection incidence independent of testing rates.

Fecal contamination of surface waters poses a potential risk to public and environmental health but can also impact the local economy and recreational activities. Determining its source could facilitate mitigation of the contamination. Fecal contamination can originate from several animals, particularly in areas where urban and agricultural activities overlap. In previous work, we developed a molecular approach to detect the presence of mammals, fish, and birds by sequencing mitochondrial DNA (mtDNA) amplicons derived from environmental DNA. In this report, we monitored the outlet of a stream located in an agricultural area for 16 weeks to detect the presence of mammals, including humans, livestock, domestic and wild mammals, birds and fish. We were able to detect mtDNA sequences affiliated to at least 73 animal lineages. Sequences affiliated to fish were proportionally the most abundant, followed by those affiliated to mammals. We observed increases in bovine and human mtDNA sequences after episodes of high flow in the watershed, suggesting that soil runoff to surface waters carried organic matter (e.g., manure, feces, wastewater) from these animals. Our approach could provide crucial information for farmers to mitigate fecal pollution generated by agricultural activities.

Toxic additives leached from tire wear particle (TWP) have been linked to some collective death events of fish, also impose impacts on zooplankton as secondary consumer in aquatic food web. In addition to direct impacts of TWP leachate at the current generation, potential delayed carryover from past exposure across multi-generational lineage may augment impacts on individual reproduction, then population maintenance. We investigated the carryover effects from persistent exposure and past TWP leachate exposure along generation passaging on the individual reproduction of rotifer, Brachionus calyciflorus, a typical zooplankton. For rotifer treated with TWP leachate across continuous 7 generations, their offspring were divided into parental exposure or no exposure in each generation. And rotifer transferred into no exposure were maintained for 3 generations to eliminate indirect exposure through their parental germ. The similar response of reproduction, via carryover effects from parental exposure, also emerged in offspring without exposure. Persistent exposure across multiple generations additively impaired individual reproduction performance by transferring from its hermetic effects in original generation, even caused final population collapse. TWP leachate could impose cascading toxicity on population persistence of zooplankton via carryover and cumulative effects on reproduction for long term, which must be considered in risk assessment and management policy to alleviate the effects of TWP.

BackgroundSurveillance of SARS-CoV-2 in wastewater offers an unbiased and near real-time tool to track circulation of SARS-CoV-2 at a local scale, next to other epidemic indicators such as hospital admissions and test data. However, individual measurements of SARS-CoV-2 in sewage are noisy, inherently variable, and can be left-censored. AimWe aimed to infer latent virus loads in a comprehensive sewage surveillance program that includes all sewage treatment plants (STPs) in the Netherlands and covers 99.6% of the Dutch population. MethodsA multilevel Bayesian penalized spline model was developed and applied to estimate time- and STP-specific virus loads based on water flow adjusted SARS-CoV-2 qRT-PCR data from 1-4 sewage samples per week for each of the >300 STPs. ResultsThe model provided an adequate fit to the data and captured the epidemic upsurges and downturns in the Netherlands, despite substantial day-to-day measurement variation. Estimated STP virus loads varied by more than two orders of magnitude, from approximately 1012 (virus particles per 100,000 persons per day) in the epidemic trough in August 2020 to almost 1015 in many STPs in January 2022. Epidemics at the local levels were slightly shifted between STPs and municipalities, which resulted in less pronounced peaks and troughs at the national level. ConclusionAlthough substantial day-to-day variation is observed in virus load measurements, wastewater-based surveillance of SARS-CoV-2 can track long-term epidemic progression at a local scale in near real-time, especially at high sampling frequency.