The study, published in the journal Air Quality, Atmosphere & Health, applied a statistical framework known as a distributed lag nonlinear model, or DLNM. Unlike conventional linear regression, this approach captures two dimensions at once: how the health risk changes across the range of an exposure, and how that risk is distributed over the days and weeks that follow. Each environmental variable was represented by a cross-basis function, and the models were fitted with a negative binomial distribution to handle the overdispersed count data. Long-term trends and seasonality were controlled with natural cubic splines of time, and day of the week was included to account for systematic weekly rhythms in hospital admissions.

The scale of the dataset is formidable. Over the decade, the city recorded an average of 284 respiratory hospitalizations per day, with daily counts ranging from zero to 1,417. Women accounted for nearly 58 percent of admissions, and the burden fell disproportionately on the youngest and oldest residents: children aged 14 and under and adults aged 65 and over together made up more than 70 percent of the daily average. The researchers caution, however, that these descriptive patterns do not demonstrate greater susceptibility to pollution by age, because the modeling was performed on total daily counts rather than age-stratified analyses.

Particulate matter emerged as the most consistent and robust risk factor. When concentrations of PM2.5, particles smaller than 2.5 micrometers, rose to their 90th percentile of about 20 micrograms per cubic meter compared with the median, the cumulative risk of respiratory hospitalization over the following 14 days increased by roughly 26 percent. Coarse PM10 particles, at a 90th percentile of 28 micrograms per cubic meter, carried an even stronger cumulative effect of about 30 percent. Crucially, these effects were acute: the risk spikes appeared primarily within the first three to seven days after exposure and then attenuated, a temporal signature consistent with particulate matter acting as an immediate irritant and inflammatory trigger rather than a slow-burning hazard.

Perhaps the most provocative finding is that PM10 outperformed PM2.5 in the strength of its association, inverting the usual assumption that fine particles are the dominant threat. The authors point to Rio’s local emission profile. Coarse particles are typically generated by resuspended road dust, construction activity, and traffic, all pervasive in a densely built coastal city. The measured PM2.5 to PM10 ratio of 0.69 confirms that coarse particles make up a substantial share of the suspended load. Coarse particles can also carry a heterogeneous mixture of biological material, crustal elements, and other irritants capable of provoking airway inflammation, and their predominance in short-lag effects suggests they act as fast-acting triggers of acute respiratory events.

The regulatory implications are hard to ignore. Average concentrations during the study period were 13 micrograms per cubic meter for PM2.5 and 19 for PM10, both below Brazil’s current national standards of 20 and 40 micrograms respectively under CONAMA Resolution 506/2024. Yet both exceed the World Health Organization’s updated guidelines, which recommend annual means of just 5 micrograms for PM2.5 and 15 for PM10. Maximum daily values frequently breached the WHO 24-hour limits outright. Detecting significant hospitalization effects at concentrations deemed acceptable by national law, the authors argue, suggests that current Brazilian standards may not adequately protect public health, and they call for closer alignment with international guidelines.

Temperature told a more intricate story. The exposure-response curve was U-shaped, with elevated risk at both cold and hot extremes. Low temperatures at the 10th percentile, around 20.8 degrees Celsius, raised cumulative risk by about 24 percent. High temperatures near 27 degrees produced a cumulative increase of roughly 20 percent, but the striking feature was timing: heat effects were delayed, peaking at lags of 8 to 14 days rather than appearing immediately. At the 99th percentile of temperature, 29 degrees, the cumulative risk more than doubled. The authors speculate that this lag reflects indirect pathways, including heat-driven photochemical formation of tropospheric ozone, prolonged exposure to poorly ventilated air-conditioned indoor environments, and the exacerbation of underlying chronic conditions over consecutive warm days.

Humidity and rainfall, by contrast, appeared protective. Higher relative humidity was associated with a 16 percent reduction in cumulative hospitalization risk at the 90th percentile, and heavy precipitation cut risk by 28 percent, with the strongest effects in the first week. Extreme rainfall at the 99th percentile was associated with a dramatic 83 percent reduction. The pattern supports a well-known atmospheric cleansing mechanism: rain scavenges particles from the air through wet deposition, temporarily lowering exposure. Low humidity, meanwhile, showed a borderline increase in risk, hinting that dry conditions may favor both pollutant persistence and pathogen survival.

The team subjected the results to extensive robustness checks. Varying the maximum lag window from 7 to 21 days left the particulate matter estimates essentially unchanged, and altering the flexibility of the lag-response function had little effect. A sensitivity analysis excluding the COVID-19 pandemic years of 2020 through 2022, when hospitalization patterns and pollution levels were disrupted, attenuated the estimates modestly but preserved both their direction and statistical significance. The one specification that mattered was the flexibility of the exposure-response curve itself: with four degrees of freedom the particulate associations lost significance, a reminder that model choices in nonlinear time-series work can shape conclusions.

The authors acknowledge the limits inherent in an ecological design. Exposure was measured as a citywide average from ten fixed monitoring stations, which cannot capture the sharp spatial gradients created by Rio’s massifs, coastal boundaries, and microclimates, nor the personal exposure differences shaped by commuting and daily activity. Gaseous pollutants such as nitrogen dioxide and ozone were not included in the final models, and interactions between pollution and weather were not directly tested. Even so, the study stands as the first of its kind in the region with such an extended time series, and its message for policymakers is concrete: short-term tools such as air quality alerts and emission controls could measurably reduce hospital burden, while the delayed heat effects argue for heat-health warning systems as climate change intensifies extreme weather in tropical cities.

Subject of Research: Nonlinear and delayed effects of particulate matter and meteorological conditions on respiratory hospitalizations in Rio de Janeiro

Article Title: Associations of particulate matter and meteorological factors with respiratory hospitalizations in Rio de Janeiro: A distributed lag nonlinear model study

Article References: de Souza Pedreira, M. F., Lorenz, C., Ynoue, R. Y., Nogueira, T., & Gioda, A. (2026). Associations of particulate matter and meteorological factors with respiratory hospitalizations in Rio de Janeiro: A distributed lag nonlinear model study. Air Quality, Atmosphere & Health, 19(10), Article 232. https://doi.org/10.1007/s11869-026-02124-z

Image Credits: AI Generated

DOI: 10.1007/s11869-026-02124-z

Keywords: air pollution, particulate matter, PM2.5, PM10, respiratory hospitalizations, distributed lag nonlinear model, Rio de Janeiro, temperature, humidity, precipitation, tropical megacity, WHO air quality guidelines

The biological rationale for targeting Wolbachia is well established. These intracellular alpha-proteobacteria are not passive passengers; they are essential partners without which filarial nematodes cannot develop normally, reproduce, or remain viable over the long term. Depleting Wolbachia with tetracycline-class antibiotics such as doxycycline therefore undermines the worm itself, sterilizing adult females, shortening adult lifespan, and reducing the inflammatory pathology associated with dead and dying parasites. Because of these effects, veterinary guidelines commonly recommend doxycycline as an adjunct to melarsomine adulticide treatment and as the central component of slower, less intensive protocols for dogs that cannot tolerate adulticide therapy. The assumption underlying these recommendations is that an adequate doxycycline course reliably drives Wolbachia burdens down to undetectable levels, at least within the circulating microfilariae that are easiest to sample and quantify.

To test that assumption quantitatively, the researchers enrolled microfilaremic, heartworm-positive dogs identified in municipalities within the target areas of Rio de Janeiro State. Owners agreed to blood draws on day 0 and again on days 60 and 90, with a five-day window around each scheduled time point, and to administer doxycycline at 10 milligrams per kilogram twice daily for 28 days. Weekly telephone follow-up calls were used to help ensure that owners maintained the dosing schedule, an important consideration in any field study where incomplete compliance could confound the results. Critically, none of the enrolled dogs received any macrocyclic lactone, the class of preventive drugs that includes ivermectin, milbemycin, and moxidectin, at any point during the study. This design choice isolated the effect of doxycycline alone, which is precisely the scenario about which the least controlled field data exist.

The analytical approach combined classical parasitology with modern molecular quantification. On each experimental day, blood samples were subjected to the modified Knott’s test, the long-standing gold-standard technique for detecting and counting microfilariae, the larval offspring of adult female worms that circulate in the bloodstream. A portion of each sample was retained and frozen at minus 20 degrees Celsius for archival purposes, while the remainder was submitted for digital PCR, a technology that partitions each sample into thousands of microscopic reactions and counts target molecules individually. Digital PCR offers an advantage over conventional quantitative PCR in that it provides absolute counts of DNA copies without the need for standard curves, making it well suited to tracking changes in the ratio of Wolbachia DNA to D. immitis DNA within the same blood sample over time.

Thirty-one microfilaremic dogs completed the study, and 27 of them remained microfilaremic throughout the entire observation period. That persistence of circulating larvae in the vast majority of animals is itself noteworthy, because it confirms that doxycycline monotherapy, at least over a 90-day horizon, does not clear microfilaremia in most naturally infected dogs. The more striking molecular result concerned the endosymbiont. By day 90, Wolbachia had been cleared to undetectable levels in 25 of the 31 dogs, demonstrating that the 10 milligrams per kilogram twice-daily dose was fully effective in those cases and that the treatment protocol, as delivered, was capable of eliminating the symbiont from the circulating parasite population in most animals.

But six dogs told a different story. In these animals, digital PCR remained positive for Wolbachia DNA at the quantitative assessment, indicating that the endosymbiont’s genetic material persisted in the bloodstream months after the antibiotic course had ended. The proportions of Wolbachia relative to D. immitis DNA on days 60 and 90 were significantly lower than on day 0, with a p-value below 0.0001, confirming that the treatment did produce a dramatic overall reduction in the symbiont burden even in these persistent cases. When the researchers compared the day 60 and day 90 proportions directly, however, the difference was not statistically significant, with a p-value of 0.3127. In other words, between day 60 and day 90 the relative Wolbachia burden in the persistent dogs plateaued rather than continuing to decline, suggesting that whatever residual signal remained was not being progressively eliminated during the final month of observation.

The authors are careful about interpretation, and their caution is instructive. They note that the data may reflect the absence of macrocyclic lactone use in the cohort, since these preventive drugs kill microfilariae directly and would be expected to remove the larval population in which residual Wolbachia DNA might reside. Alternatively, dogs carrying higher adult worm burdens might simply harbor more symbiont-containing material than a standard doxycycline course can fully deplete. Yet the team explicitly acknowledges that it is not possible to confidently conclude that these factors entirely underpin the observations. The residual DNA signal could represent dead or dying bacteria whose genetic material has not yet been cleared from host tissues, or it could indicate genuinely surviving Wolbachia in a subset of worms or in a subpopulation of the symbiont itself. Distinguishing between these possibilities matters enormously, because DNA persistence from dead organisms is biologically benign, whereas surviving symbionts could repopulate their hosts once antibiotic pressure is removed.

This ambiguity leads directly to the study’s most important recommendation: further research should investigate whether the persistence is related to a lack of efficacy of doxycycline against certain Wolbachia subpopulations or to other, still unidentified factors. The idea of resistant or tolerant symbiont subpopulations is not far-fetched. Bacteria exposed to bacteriostatic drugs such as tetracyclines can enter low-metabolic states that permit survival, and genetic variation among Wolbachia strains infecting different worm individuals, or even different tissues within a single worm, could produce heterogeneous drug susceptibility. If a subpopulation of Wolbachia can withstand a full standard course of doxycycline, the implications extend beyond this single cohort, potentially affecting the reliability of doxycycline-based protocols in regions where such regimens are the only practical option for infected dogs.

For practicing veterinarians and pet owners, the study’s findings should be read as a call for measured reevaluation rather than alarm. The treatment was demonstrably effective in the majority of dogs, and even in the six persistent animals the symbiont burden fell dramatically and remained suppressed. What the study challenges is the assumption that a standard doxycycline course uniformly and permanently eliminates Wolbachia from every treated animal, particularly when no macrocyclic lactone is administered concurrently. It also highlights the value of digital PCR as a surveillance tool, since conventional microscopy of microfilariae would have revealed nothing about the symbiont status of these animals. As heartworm-endemic regions expand and drug-resistant parasite populations emerge, understanding the durability of the doxycycline-Wolbachia axis becomes increasingly consequential. The Rio de Janeiro cohort, small as it is, provides a quantitative baseline for that conversation and a clear agenda for the studies that must follow.

Subject of Research: Persistence of Wolbachia endosymbiont DNA in heartworm-infected dogs after doxycycline-only treatment

Article Title: Persistence of Wolbachia DNA in Dirofilaria immitis-infected canines after doxycycline-only treatment in Rio de Janeiro State, Brazil

Article References: Carithers, D., Alberigi, B., Scott, F., Mendes-de-Almeida, F., Borges, D., Labarthe, N., Brandão, Y., Cunha, R. S., de Souza Ramos, E. A., Molento, M., Yoon, S., McCall, J., & Harrington, J. (2026). Persistence of Wolbachia DNA in Dirofilaria immitis-infected canines after doxycycline-only treatment in Rio de Janeiro State, Brazil. Parasites & Vectors. https://doi.org/10.1186/s13071-026-07621-9

Image Credits: AI Generated

DOI: 10.1186/s13071-026-07621-9

Keywords: Wolbachia, Dirofilaria immitis, heartworm, doxycycline, dogs, digital PCR, microfilariae, Rio de Janeiro, veterinary parasitology, macrocyclic lactones, endosymbiont, Parasites & Vectors

The new tally, compiled by botanist Marcus A. Nadruz Coelho of the Rio de Janeiro Botanical Garden Research Institute and Cecília Cronemberger of the Chico Mendes Institute for Biodiversity Conservation, updates and expands every previous account of the park’s vegetation. The breakdown is remarkable in its breadth: 2,342 species of flowering plants, 433 ferns and lycophytes, 250 bryophytes, and a single gymnosperm. To put that figure in perspective, the park harbors roughly 38 percent of all plant species known to the entire state of Rio de Janeiro within an area representing only about half a percent of the state’s territory. The list has grown 26.7 percent since the most recent compilation in the park’s management plan, which recorded 2,268 species, and 34.4 percent since Carlos Rizzini published his pioneering Flora Organensis in 1954, which identified 2,029 species.

Reaching these numbers required years of patient fieldwork combined with an ambitious archival detective operation. Between 2007 and 2011, the researchers conducted systematic collections of fertile plant material across all vegetation types in the park, prioritizing zones flagged as poorly inventoried. They used the walking method, an expedited qualitative survey technique in which collectors traverse trails and terrain on foot, photographing and pressing specimens for deposition at the herbarium of the Rio de Janeiro Botanical Garden Research Institute. But fieldwork alone could not capture two centuries of accumulated knowledge. The team then combed through the Carlos Toledo Rizzini Reference Collection housed at the park headquarters, queried the national JABOT and SPECIESLINK online databases, and consulted dozens of international herbaria across Europe and the Americas, tracking down specimens gathered by naturalists as far back as the 1820s.

Those historical records tell their own story of scientific obsession. The oldest angiosperm collections in the park date to March 1823, when L. Riedel gathered Floscopa glabrata, followed by H. Beyrich’s 1828 collection of Ichnanthus nemoralis, a grass whose duplicate now resides in the United States National Herbarium as a copy of a specimen once held in Berlin. The oldest fern record, Adiantum cuneatum, was collected by Gaudichaud in 1831, while the earliest bryophyte specimens, Entosthodon bonplandii and Funaria hygrometrica, were gathered by George Gardner in 1836. Established in 1939 as Brazil’s third oldest national park, Serra dos Órgãos had already been visited decades earlier by legendary naturalists such as Spix and Martius, whose Flora Brasiliensis project helped lay the foundations of Brazilian botany.

What makes the park so extraordinarily diverse is its topography. The terrain is rugged and dramatic, with altitudes ranging from 80 meters to 2,275 meters at Pedra do Sino, the park’s highest summit. This vertical span generates a staircase of distinct vegetation zones: submontane forest on the lower slopes between 50 and 500 meters, montane forest on the plateaus between 500 and 1,500 meters, upper-montane forest above that, and finally the campos de altitude, open herbaceous-shrub formations that begin around 1,800 meters on the ocean-facing slopes and 1,600 meters on the inland side. About 37 percent of the park is upper-montane forest, 24 percent campos de altitude, 22 percent montane forest and 17 percent submontane forest. The climate amplifies this variety. Under the Köppen-Geiger system the region is classified as temperate oceanic, with no dry season and orographic rainfall that produces the highest precipitation in Rio de Janeiro state, exceeding 2,000 millimeters annually. Winter minimums can plunge to 1 degree Celsius and, at the highest elevations, down to minus 5 degrees, conditions more reminiscent of temperate mountains than tropical lowlands.

The campos de altitude, isolated like islands on the mountaintops, are evolutionary laboratories. Because these high-elevation habitats are cut off from one another, their flora and fauna have evolved in isolation, producing exceptional endemism. Previous research identified 23 threatened plant species in the park’s high-altitude grasslands, and a single valley was found to hold 347 plant species, 66 of them endemic to the formation and 13 exclusive to the park. The new inventory confirms this pattern across the whole protected area: 28 species are endemic to the park itself, including the aroid Anthurium cronembergerae, the bromeliad Tillandsia organensis, the melastome Bertolonia organensis, and two lycophytes and two bryophytes found nowhere else on Earth. Another 190 species are endemic to Rio de Janeiro state, meaning the park alone harbors 22.17 percent of the 884 species endemic to the state.

The dominant plant families mirror the broader signature of the Atlantic Forest. Orchidaceae leads with 285 species, followed by Asteraceae with 171, Melastomataceae with 158, Myrtaceae with 144, Rubiaceae with 115, and Bromeliaceae with 107, with Piperaceae, Dryopteridaceae, Polypodiaceae and Fabaceae rounding out the top ten. Together these ten families account for 34 percent of local diversity. The prominence of orchids, bromeliads and polypodiaceous ferns underscores the critical role of epiphytes, plants that live on other plants, in tropical rainforest ecosystems. The park also shelters 103 species classified in IUCN threat categories, including 20 angiosperms listed as Critically Endangered and one, the rubiaceous herb Hindsia violacea, considered Extinct. Tragically, the inventory suggests that extinction may not be permanent: renewed collection in rugged, rarely visited terrain could rediscover species believed lost, a phenomenon documented repeatedly in well-studied floras worldwide.

Yet the inventory also exposes a sobering truth about the limits of knowledge. A total of 1,195 species, nearly 38 percent of the park’s flora, are known from only a single collection record and are therefore considered locally rare, with 503 more known from just two records. The researchers attribute this to a combination of collection bias and the sheer habitat diversity generated by the altitudinal gradient. Accessibility bias, the tendency for scientific knowledge to concentrate near cities and along easy routes, shapes our understanding of species richness at every scale. Three of the five richest protected areas in Brazil, including Serra dos Órgãos, Itatiaia National Park and Tinguá Biological Reserve, lie in Rio de Janeiro state, historically the main gateway for European naturalists, while remote Amazonian parks such as Serra da Neblina, with 1,047 recorded species, remain comparatively unexplored. Even within the park, certain rugged areas remain undersampled, a pattern echoed in mammal surveys of the same landscape.

The consequences of this work extend well beyond taxonomy. By identifying which species are rare, endemic or threatened, the inventory provides a scientific foundation for conservation planning, reforestation efforts and the possible establishment of additional protected areas in the Serra do Mar corridor, which protects more than 800,000 hectares of Atlantic Forest across São Paulo, Rio de Janeiro and Paraná states. The Atlantic Forest has lost roughly 76 percent of its original cover, and in Rio de Janeiro state only 18.7 percent of forest remains, much of it in small, unprotected fragments. Against that backdrop, a single park holding 48 percent of the state’s known fern species and 16 percent of its angiosperm diversity is nothing short of extraordinary. The authors argue that encouraging further research and botanical collection could raise the representation of locally rare species, recover supposedly extinct plants, and reveal species entirely new to science, proving that even a forest two centuries in the study still guards secrets worth climbing mountains to find.

Subject of Research: Floristic inventory and conservation of native vascular plants and bryophytes in Serra dos Órgãos National Park, Atlantic Forest, Brazil

Article Title: Updated list of native flora of Serra dos Órgãos National Park, Rio de Janeiro state, Brazil

Article References: Nadruz Coelho, M. A., & Cronemberger, C. (2025). Updated list of native flora of Serra dos Órgãos National Park, Rio de Janeiro state, Brazil. Discover Conservation, 2(1), Article 38. https://doi.org/10.1007/s44353-025-00052-0

Image Credits: AI Generated

DOI: 10.1007/s44353-025-00052-0

Keywords: Atlantic Forest, biodiversity, botany, Serra dos Órgãos National Park, endemic species, floristic inventory, campos de altitude, conservation, orchids, ferns, bryophytes, Rio de Janeiro

Juliana Bem-Lignani of the State University of Rio de Janeiro and Rosana Salles-Costa of the Federal University of Rio de Janeiro analyzed data from the First Survey on Food and Nutritional Insecurity in Rio de Janeiro, conducted in 2024. The survey drew a probabilistic sample of 2,000 households spread across the municipality’s five residential zones: South, Central, North, West and Southwest. Because the sample was designed to represent the city’s households rather than merely the people willing to answer a questionnaire, the results can be generalized to the population of each territory, a critical feature for a study whose central question is precisely geographic.

The instrument at the heart of the study was the Portuguese version of the Water Insecurity Experiences Scale, known as WISE. Unlike measures that simply ask whether a home has a piped connection, experience-based scales probe what actually happens in daily life: whether there was enough water for drinking and cooking, whether the supply was interrupted, whether households had to change routines to cope. This distinction matters technically because a connection to the network does not guarantee an adequate, regular and safe flow, and the authors argue that lived experience captures dimensions of water access that infrastructural indicators miss.

The territorial pattern that emerged was stark. The South and Southwest zones, home to better socioeconomic conditions, reported daily water supply in 82.2 percent and 75.9 percent of households respectively. By contrast, the Central and North zones showed worse socioeconomic indicators and more frequent supply interruptions, affecting 19.2 percent and 20.6 percent of households. The West zone occupied an intermediate position overall but stood out for rationing, with 30.8 percent of households reporting intermittent service. These are not marginal differences; in a city where water is constitutionally recognized as a social right, a fifth of households in some territories facing interruptions represents a substantial equity gap.

Experience-based water insecurity tracked the same geography. In the South and Southwest zones, 25.1 percent and 27.1 percent of households respectively reported water insecurity. In the Central and North zones the figures climbed to 46.9 percent and 48.3 percent, nearly one household in two. In other words, residents of the city’s central and northern territories were experiencing water insecurity at nearly double the rate of those in the wealthier southern coast, a gradient that parallels well-documented disparities in income, food security and health across the same zones.

To test whether the association between territory and water insecurity was real rather than an artifact of household composition, the researchers used multinomial logistic regression, a statistical model suited to outcomes with multiple ordered or unordered categories. Here the outcome was water insecurity at low, moderate or higher levels, and the models were adjusted for the socioeconomic characteristics of the household reference person and for the household’s water access conditions. Adjusting for these covariates is what allows the analysis to ask whether place itself, with all its social and infrastructural history, adds explanatory power beyond the individual household’s profile.

The answer was yes. Compared with households in the South zone, living in the West zone was associated with 2.4 times the odds of low water insecurity, with a 95 percent confidence interval of 1.5 to 3.7, and living in the North zone carried 2.1 times the odds, with a confidence interval of 1.3 to 3.5. In the Central zone, households had 2.5 times the odds of moderate water insecurity relative to the South, with a confidence interval of 1.2 to 5.2. Because these intervals exclude one, the associations are statistically robust at conventional thresholds, and the consistency of the twofold pattern across separate zones strengthens the interpretation that territory is a meaningful analytical unit for water insecurity.

The study’s conceptual framing draws on the idea that access to water can serve as a marker of social inequities more broadly. Brazil recognizes water as a social right, yet the persistence of unequal access, reliability and quality means that formal legal recognition has not translated into uniform lived experience. The authors conclude that the differences between territories reflect and reinforce social inequalities, and that being connected to the water network alone does not ensure an adequate supply. That finding carries direct policy weight: investments that stop at extending pipes may leave untouched the interruptions, rationing and quality problems that define insecure water access in the poorest territories.

For Rio de Janeiro, the implications point toward policies that target structural and social determinants rather than infrastructure alone. The municipality’s water system is operated by the State Water and Sewage Company, and the city’s history of pronounced territorial disparity, intensified by economic shocks, means that rationing and interruption regimes fall unevenly on households with the fewest resources to buffer them, such as those unable to buy bottled water or store large reserves. The researchers suggest that water insecurity should be monitored alongside food insecurity as a dimension of social inequality, an approach reflected in the survey’s integrated design.

The study was approved by the Research Ethics Committee of the Clementino Fraga Filho University Hospital at the Federal University of Rio de Janeiro, and all participants gave informed consent. Funded by Brazil’s National Council for Scientific and Technological Development, the Rio de Janeiro State Research Support Foundation and the city’s municipal council, the work illustrates how experience-based measurement combined with territory-level sampling can turn a diffuse sense of urban unfairness into precise, actionable evidence. As climate variability tightens pressure on urban water systems worldwide, the Rio findings offer a replicable template: map the lived experience of water insecurity, match it to the social geography of the city, and direct policy where the odds are doubled.

Subject of Research: Association between territorial socioeconomic inequality and household water insecurity in Rio de Janeiro

Article Title: Territories marked by social inequities associated with household water insecurity in Rio de Janeiro/Brasil

Article References: Bem-Lignani, J., & Salles-Costa, R. (2026). Territories marked by social inequities associated with household water insecurity in Rio de Janeiro/Brasil. International Journal for Equity in Health. https://doi.org/10.1186/s12939-026-03020-9

Image Credits: AI Generated

DOI: 10.1186/s12939-026-03020-9

Keywords: water insecurity, Rio de Janeiro, social inequality, WISE scale, household water access, urban equity, public health, Brazil, cross-sectional study, territorial disparities, water policy, socioeconomic factors