High-risk spatial clusters for Zika, dengue, and chikungunya in Rio de Janeiro, Brazil.

OBJECTIVE: To analyze the spatial distribution and identify high-risk spatial clusters of Zika, dengue, and chikungunya (ZDC), in the city of Rio de Janeiro, Brazil, and their socioeconomic status. METHODS: An ecological study based on data from a seroprevalence survey. Using a rapid diagnostic test to detect the arboviruses, 2,114 individuals were tested in 2018. The spatial distribution was analyzed using kernel estimation. To detect high-risk spatial clusters of arboviruses, we used multivariate scan statistics. The Social Development Index (SDI) was considered in the analysis of socioeconomic status. RESULTS: Among the 2,114 individuals, 1,714 (81.1%) were positive for at least one arbovirus investigated. The kernel estimation showed positive individuals for at least one arbovirus in all regions of the city, with hot spots in the North, coincident with regions with very low or low SDI. The scan statistic detected three significant (p<0.05) high-risk spatial clusters for Zika, dengue, and chikungunya viruses. These clusters correspond to 35.7% (n=613) of all positive individuals of the sample. The most likely cluster was in the North (cluster 1) and overlapped regions with very low and low SDI. Clusters 2 and 3 were in the West and overlapping regions with low and very low SDI, respectively. The highest values of relative risks were in cluster 1 for CHIKV (1.97), in cluster 2 for ZIKV (1.58), and in cluster 3 for CHIKV (1.44). Regarding outcomes in the clusters, the Flavivirus had the highest frequency in clusters 1, 2, and 3 (42.83%, 54.46%, and 52.08%, respectively). CONCLUSION: We found an over-risk for arboviruses in areas with the worst socioeconomic conditions in Rio de Janeiro. Moreover, the highest concentration of people negative for arboviruses occurred in areas considered to have better living conditions.

High-risk spatial clusters for Zika, dengue, and chikungunya in Rio de Janeiro, Brazil

ABSTRACT OBJECTIVE To analyze the spatial distribution and identify high-risk spatial clusters of Zika, dengue, and chikungunya (ZDC), in the city of Rio de Janeiro, Brazil, and their socioeconomic status. METHODS An ecological study based on data from a seroprevalence survey. Using a rapid diagnostic test to detect the arboviruses, 2,114 individuals were tested in 2018. The spatial distribution was analyzed using kernel estimation. To detect high-risk spatial clusters of arboviruses, we used multivariate scan statistics. The Social Development Index (SDI) was considered in the analysis of socioeconomic status. RESULTS Among the 2,114 individuals, 1,714 (81.1%) were positive for at least one arbovirus investigated. The kernel estimation showed positive individuals for at least one arbovirus in all regions of the city, with hot spots in the North, coincident with regions with very low or low SDI. The scan statistic detected three significant (p<0.05) high-risk spatial clusters for Zika, dengue, and chikungunya viruses. These clusters correspond to 35.7% (n=613) of all positive individuals of the sample. The most likely cluster was in the North (cluster 1) and overlapped regions with very low and low SDI. Clusters 2 and 3 were in the West and overlapping regions with low and very low SDI, respectively. The highest values of relative risks were in cluster 1 for CHIKV (1.97), in cluster 2 for ZIKV (1.58), and in cluster 3 for CHIKV (1.44). Regarding outcomes in the clusters, the Flavivirus had the highest frequency in clusters 1, 2, and 3 (42.83%, 54.46%, and 52.08%, respectively). CONCLUSION We found an over-risk for arboviruses in areas with the worst socioeconomic conditions in Rio de Janeiro. Moreover, the highest concentration of people negative for arboviruses occurred in areas considered to have better living conditions.

Spatial analysis of dengue incidence and Aedes aegypti ovitrap surveillance in Belo Horizonte, Brazil.

OBJECTIVES: Understanding the intra-urban spatial dynamics of Aedes aegypti and dengue transmission is important to effectively guide vector control. Ovitraps are a sensitive, cost-effective vector surveillance tool, yet few longitudinal studies have evaluated ovitrap indices and dengue occurrence. We aimed to assess the spatial patterns of dengue incidence and Ae. aegypti ovitrap positivity index (OPI) over time and to examine the spatial relationship between these two variables. METHODS: This study used 12 years (2007-2018) of dengue case records and biweekly Ae. aegypti ovitrap data in Belo Horizonte, Brazil. We aggregated data by year and health centre catchment area (n = 152) and used both univariate and bivariate global Moran's I statistic and LISA to evaluate spatial clustering. RESULTS: Annual dengue incidence ranged from 18 to 6262/100 000 residents and displayed spatial autocorrelation in 10/12 years, with shifting areas of high incidence. Annual OPI ranged from 35.7 to 47.6% and was clustered in all study years, but unlike dengue had consistent spatial patterns over time. Bivariate analysis found both positive (6/12 years) and negative (1/12 years) spatial associations between the two variables. CONCLUSIONS: Low detected presence of Ae. aegypti was not a limiting factor in dengue transmission. However, stable spatial distribution of OPI suggests that certain areas may have persistent breeding sites. Future research should identify factors related to persistent Ae. aegypti hotspots to better guide vector management. Vector control efforts should be paired with additional data on population immunity, circulating serotypes and urban factors to better predict and control outbreaks.

OBJECTIFS: La compréhension de la dynamique spatiale intra-urbaine d'Aedes aegypti et de la transmission de la dengue est importante pour guider efficacement la lutte antivectorielle. Les ovitraps sont un outil de surveillance des vecteurs sensible et rentable, mais peu d'études longitudinales ont évalué les indices d'ovitrap et l'occurrence de la dengue. Nous visions à évaluer les modèles spatiaux de l'incidence de la dengue et de l'indice de positivité d'ovitrap (OPI) d'Ae. aegypti au fil du temps, et à examiner la relation spatiale entre ces deux variables. MÉTHODES: Cette étude a utilisé des dossiers de cas de dengue et des données bihebdomadaires d'ovitrap Ae. aegypti sur 12 ans (2007-2018) à Belo Horizonte, au Brésil. Nous avons agrégé les données par année et par zone d'étude du centre de santé (n = 152) et avons utilisé à la fois la statistique I globale de Moran univariée et bivariée et LISA pour évaluer le regroupement spatial. RÉSULTATS: L'incidence annuelle de la dengue variait de 18 à 6.262/100.000 habitants et affichait une autocorrélation spatiale en 10/12 ans, avec des zones de déplacement de forte incidence. L'OPI annuel variait de 35,7 à 47,6% et était groupé dans toutes les années d'étude, mais contrairement à la dengue, il avait des modèles spatiaux consistents au fil du temps. Une analyse bivariée a trouvé des associations spatiales positives (6/12 ans) et négatives (1/12 ans) entre les deux variables. CONCLUSIONS: La détection d'une faible présence d'Ae. aegypti n'était pas un facteur limitant de la transmission de la dengue. Cependant, la distribution spatiale stable de l'OPI suggère que certaines zones peuvent avoir des sites de reproduction persistants. Les recherches futures devraient identifier les facteurs liés à des hotspots persistants d'Ae. aegypti pour mieux guider la gestion des vecteurs. Les efforts de lutte antivectorielle devraient être associés à des données supplémentaires sur l'immunité de la population, les sérotypes circulants et les facteurs urbains pour mieux prévoir et contrôler les flambées.

Zika, dengue and chikungunya population prevalence in Rio de Janeiro city, Brazil, and the importance of seroprevalence studies to estimate the real number of infected individuals.

In the last 40 years, Latin America countries, including Brazil, have suffered from the emergence and reemergence of arboviruses, first Dengue (DENV) and recently Zika (ZIKV) and Chikungunya (CHIKV). All three arboviruses are currently endemic in Brazil and have caused major outbreaks in recent years. Rio de Janeiro city, host of the last Summer Olympic Games and the Football World Cup, has been specially affected by them. A surveillance system based on symptomatic reports is in place in Rio, but the true number of affected individuals is unknown due to the great number of Zika, Dengue and Chikungunya asymptomatic cases. Seroprevalence studies are more suitable to evaluate the real number of cases in a given population. We performed a populational seroprevalence survey in Rio, with recruitment of a sample of volunteers of all ages and gender from July to October 2018, within randomly selected census tracts and household. A total of 2,120 volunteers were interviewed and tested with rapid immunochromatographic test for ZIKV, DENV and CHIKV. Individuals with positive results for IgG and/or IgM from only one virus were classified accordingly, while those with test results positive for both ZIKV and DENV were classified as flaviviruses. We corrected for sample design and non-response in data analysis, and calculated point estimate prevalence and 95% confidence intervals for each virus. Arbovirus prevalence in the Rio's population (n = 6,688,927) was estimated at 48.6% [95% CI 44.8-52.4] (n = 3,254,121) for flaviviruses and at 18.0% [95% CI 14.8-21.2] (n = 1,204,765) for CHIKV. Approximately 17.0% [95% CI 14.1-20.1] (n = 1,145,674) of Rio´s population had no contact with any of the three arboviruses. The reported cases of Zika, Dengue and Chikungunya by the current surveillance system in place is insufficient to estimate their real numbers, and our data indicate that Zika seroprevalence could be at least five times and Chikungunya 45 times bigger. The high number of individuals having never been infected by any of the three arboviruses, may indicate a proper scenario for future outbreaks.

[Spaces of production of cutaneous leishmaniasis in the state of Rio de Janeiro, Brazil]. / Espaços de produção da leishmaniose tegumentar americana no estado do Rio de Janeiro, Brasil.

The scope of this research was to identify and characterize spatial units of epidemiological relevance in the state of Rio de Janeiro, through the highest concentrations of cutaneous leishmaniasis (CL) from 1980 to 2012, considering the geographical aspects. SUCAM, FUNASA and SINAN databases were consulted. A method of adjustment of spatially referenced data for demarcation of the regions with the highest concentrations of cases called circuits and poles was applied. These were superimposed on the socioenvironmental indicator maps. Of the total cases registered in the period, 87% occurred in the municipalities located in the resulting circuits and poles. The variations in the occurrence of cases in the different circuits and poles were not related to the socioenvironmental indicators. The identification of the circuits and poles can subsidize the state CL program of the prioritization of strategies of prevention and control actions and the optimization of the resources of the program. These regions, which are more stable than the localities, allow surveillance and control operations in locations with many cases and in other locations in the identified risk area, because they have the same characteristics as those already affected.

O objetivo foi identificar e caracterizar unidades espaciais de relevância epidemiológica no estado do Rio de Janeiro, por meio das maiores concentrações de casos de leishmaniose tegumentar (LT) no período de 1980 a 2012, considerando os conceitos da geografia. Utilizou-se bancos de dados da SUCAM, FUNASA e SINAN. Foi aplicado um método de ajustamento de dados espacialmente referenciados para delimitação das regiões com as maiores concentrações de densidades de casos chamadas circuitos e polos. Estes foram sobrepostos aos mapas de indicadores socioambientais. Do total de casos registrados no período, 87% ocorreram nos municípios localizados nos circuitos e polos resultantes. As variações na ocorrência de casos nos diferentes circuitos e polos não tiveram relação com os indicadores socioambientais. A identificação dos circuitos e polos pode subsidiar o programa estadual da LT para a priorização de estratégias de ações de prevenção e controle e a otimização dos recursos do programa. Essas regiões, mais estáveis que as localidades, permitem operações de vigilância e controle nas localidades com muitos casos e nas demais da área de risco identificada, por terem as mesmas características daquelas já afetadas.

Espaços de produção da leishmaniose tegumentar americana no estado do Rio de Janeiro, Brasil / Spaces of production of cutaneous leishmaniasis in the state of Rio de Janeiro, Brazil

Resumo O objetivo foi identificar e caracterizar unidades espaciais de relevância epidemiológica no estado do Rio de Janeiro, por meio das maiores concentrações de casos de leishmaniose tegumentar (LT) no período de 1980 a 2012, considerando os conceitos da geografia. Utilizou-se bancos de dados da SUCAM, FUNASA e SINAN. Foi aplicado um método de ajustamento de dados espacialmente referenciados para delimitação das regiões com as maiores concentrações de densidades de casos chamadas circuitos e polos. Estes foram sobrepostos aos mapas de indicadores socioambientais. Do total de casos registrados no período, 87% ocorreram nos municípios localizados nos circuitos e polos resultantes. As variações na ocorrência de casos nos diferentes circuitos e polos não tiveram relação com os indicadores socioambientais. A identificação dos circuitos e polos pode subsidiar o programa estadual da LT para a priorização de estratégias de ações de prevenção e controle e a otimização dos recursos do programa. Essas regiões, mais estáveis que as localidades, permitem operações de vigilância e controle nas localidades com muitos casos e nas demais da área de risco identificada, por terem as mesmas características daquelas já afetadas.

Abstract The scope of this research was to identify and characterize spatial units of epidemiological relevance in the state of Rio de Janeiro, through the highest concentrations of cutaneous leishmaniasis (CL) from 1980 to 2012, considering the geographical aspects. SUCAM, FUNASA and SINAN databases were consulted. A method of adjustment of spatially referenced data for demarcation of the regions with the highest concentrations of cases called circuits and poles was applied. These were superimposed on the socioenvironmental indicator maps. Of the total cases registered in the period, 87% occurred in the municipalities located in the resulting circuits and poles. The variations in the occurrence of cases in the different circuits and poles were not related to the socioenvironmental indicators. The identification of the circuits and poles can subsidize the state CL program of the prioritization of strategies of prevention and control actions and the optimization of the resources of the program. These regions, which are more stable than the localities, allow surveillance and control operations in locations with many cases and in other locations in the identified risk area, because they have the same characteristics as those already affected.

Visceral leishmaniasis control actions: epidemiological indicators for its effectiveness evaluation in a Brazilian urban area.

This research applies indicators concerning control of the visceral leishmaniasis canine reservoir in the city of Belo Horizonte, Minas Gerais State, Brazil. Data were obtained from the Zoonoses Control Information System (SCZOO) and the Brazilian Information System on Diseases of Notification (SINAN) database. First we analyzed (i) existing associations between canine epidemiological indicators, where the dependent variable was the canine seroprevalence A (2007 to 2013), and the independent variables were, as follows: canine seroprevalence B (2006 to 2012); percentage of positive dogs by ELISA test reagents that were not euthanized; the relationship between the human and canine population; canine population testing coverage by census surveys; and the years of study (2006 to 2013); (ii) then, we examined the association between human visceral leishmaniasis (HVL) cases between 2007 to 2013 and the mentioned variables related to dogs and years. Statistical analysis was done by a generalized linear model (GLM). One unit increases in canine seroprevalence B and canine seroprevalence A were associated to 13% and 12% increases in HVL rates, respectively. The increase in one human/dog ratio unit was associated with a 13% decrease in HVL rates. Canine seroprevalence, human/dog ratio and non-euthanasia of ELISA-reactive dogs in the environment were adequate indicators for analyzing the canine enzootic transmission and the occurrence of HVL cases.

Hot spots of leprosy in the endemic area of São Luís, Maranhão State, Northeastern Brazil.

BACKGROUND: Despite the decreasing of leprosy cases in Brazil, its occurrence remains high in certain Brazilian cities. The aim of the study was to analyze the spatial pattern of leprosy in São Luís, capital of Maranhão State, Northeastern Brazil. METHODOLOGY: An ecological study was carried out based on secondary data from leprosy cases and contacts reported in the Notification of Injury Information System in2015, and information on residency domiciles in three districts in the city. RESULTS: A positive correlation was found between the leprosy cases and the average number of residents per household, and households with open sewage, garbage accumulated, with street identification, persons without income, dependents and the poor. A negative correlation between cases and households with a sidewalk, literate people and 60 years old or more were identified. The seropositivity of contacts examined using the ML Flow test was of 23.19%. The disease presents a heterogeneous spatial pattern, with hyperendemic clusters. CONCLUSIONS: The spatialization of both leprosy cases and contacts and the identification of areas presenting the highest concentration of the disease in each district is important and constitutes an important tool to subsidize disease-control actions.

Visceral leishmaniasis control actions: epidemiological indicators for its effectiveness evaluation in a Brazilian urban area / Ações de controle da leishmaniose visceral: indicadores epidemiológicos da avaliação de efetividade em uma área urbana brasileira / Acciones de control de la leishmaniosis visceral: indicadores epidemiológicos de la evaluación de efectividad en un área urbana brasileña

Abstract: This research applies indicators concerning control of the visceral leishmaniasis canine reservoir in the city of Belo Horizonte, Minas Gerais State, Brazil. Data were obtained from the Zoonoses Control Information System (SCZOO) and the Brazilian Information System on Diseases of Notification (SINAN) database. First we analyzed (i) existing associations between canine epidemiological indicators, where the dependent variable was the canine seroprevalence A (2007 to 2013), and the independent variables were, as follows: canine seroprevalence B (2006 to 2012); percentage of positive dogs by ELISA test reagents that were not euthanized; the relationship between the human and canine population; canine population testing coverage by census surveys; and the years of study (2006 to 2013); (ii) then, we examined the association between human visceral leishmaniasis (HVL) cases between 2007 to 2013 and the mentioned variables related to dogs and years. Statistical analysis was done by a generalized linear model (GLM). One unit increases in canine seroprevalence B and canine seroprevalence A were associated to 13% and 12% increases in HVL rates, respectively. The increase in one human/dog ratio unit was associated with a 13% decrease in HVL rates. Canine seroprevalence, human/dog ratio and non-euthanasia of ELISA-reactive dogs in the environment were adequate indicators for analyzing the canine enzootic transmission and the occurrence of HVL cases.

Resumo: O estudo aplica indicadores referentes ao controle do reservatório canino da leishmaniose visceral na cidade de Belo Horizonte, Minas Gerais, Brasil. Os dados foram obtidos do Sistema de Controle de Zoonoses (SCZOO) e do Sistema de Informação de Agravos de Notificação (SINAN). Começamos com a análise das associações existentes entre indicadores epidemiológicos caninos, onde a variável dependente foi a soroprevalência canina-A (de 2007 a 2013) e a variável independente foi a soroprevalência canina-B (de 2006 a 2012); o percentual de cães positivos de acordo com o teste ELISA e que não foram sacrificados; a relação entre as populações humana e canina; a cobertura da testagem da população canina de acordo com inquéritos censitários e os anos de estudo (de 2006 a 2013). Em seguida, examinamos a associação entre casos de leishmaniose visceral humana (LVH) entre 2007 e 2013 e as variáveis citadas relacionadas aos cães e aos anos. A análise estatística usou um modelo linear generalizado (MLG). Os aumentos de uma unidade na soroprevalência canina-B e soroprevalência canina-A estiveram associados a aumentos de 13% e 12% nas taxas de LVH, respectivamente. Um aumento de uma unidade na razão humano/cão esteve associado a uma diminuição de 13% nas taxas de LVH. A soroprevalência canina, a relação humano/cão e a não-eutanásia de cães ELISA-reativos foram indicadores adequados para analisar a transmissão enzoótica canina e a ocorrência de casos de LVH.

Resumen: El estudio aplica indicadores referentes al control del reservorio canino de la leishmaniosis visceral en la ciudad de Belo Horizonte, Minas Gerais, Brasil. Los datos fueron obtenidos del Sistema de Control de Zoonosis (SCZOO) y del Sistema Brasileño de Información de Enfermedades de Notificación (SINAN). Comenzamos con el análisis de las asociaciones existentes entre indicadores epidemiológicos caninos, donde la variable dependiente fue la seroprevalencia canina-A (de 2007 a 2013) y la variable independiente fue la seroprevalencia canina-B (de 2006 a 2012); el porcentaje de perros positivos, de acuerdo con el test ELISA, y que no fueron sacrificados; la relación entre las poblaciones humana y canina; la cobertura del test de la población canina, de acuerdo con encuestas censales y los años de estudio (de 2006 a 2013). En seguida, examinamos la asociación entre casos de leishmaniosis visceral humana (LVH) entre 2007 y 2013 y las variables citadas, relacionadas con los perros y los años. El análisis estadístico usó un modelo lineal generalizado (MLG). Los aumentos de una unidad en la seroprevalencia canina-B y seroprevalencia canina-A estuvieron asociados a aumentos de 13% y 12% en las tasas de LVH, respectivamente. Un aumento de una unidad en la razón humano/perro estuvo asociado a una disminución de un 13% en las tasas de LVH. La seroprevalencia canina, la relación humano/perro y la no-eutanasia de perros ELISA-reactivos fueron indicadores adecuados para analizar la transmisión enzoótica canina y la ocurrencia de casos de LVH.

Spatial pattern of the environmental exposure to tin in the vicinity of an alloy industry in Volta Redonda, Rio de Janeiro State, Brazil.

Despite being widely used in industry, the literature on tin and its effects in humans is scarce, especially regarding reference values in biological indicators such as blood and urine. Similarly, environmental limits are also rare. This study sought to assess the spatial distribution of hotspots in the environmental exposure to tin in the vicinity of an alloy industry in the south region of the state of Rio de Janeiro, Brazil. The study population consisted of 74 adults. Graphite furnace atomic absorption spectrometry determined tin in all samples. Households and points around the industry were georeferenced with the use of GPS to identify the most intense tin sites. Results of the first and second campaigns ranged from 0.022 to 0.153 and 0.003 to 0.445µg m-3 for the atmospheric air, whereas such ranges were 0.64 to 1.61 and 1.97 to 8.54µg m-2 for household dust, respectively. The mean tin concentration found in the blood of the population was 3.85 ± 1.57µg L-1. In urine the value was 3.56 ± 1.88µg L-1. The kernel map showed the highest spatial concentrations of tin in household dust in the eastern region of the industry. In the first sampling, atmospheric air samples presented the most elevated concentrations in the southwest and southeast. Although the direction of the wind was northwest, potentially high risks were concentrated in the central area in the second collection. The largest hotspots were in the north, south and southeast regions; however, urine samples showed medium to high levels in the west and east regions. Regarding blood samples, the greatest difference was the absence of hotspot areas in the west. Environmental monitoring becomes necessary to better assess the exposure to tin.

Spatial pattern of the environmental exposure to tin in the vicinity of an alloy industry in Volta Redonda, Rio de Janeiro State, Brazil / Padrão espacial da exposição ambiental ao estanho nos arredores de uma indústria de ligas metálicas em Volta Redonda, Estado do Rio de Janeiro, Brasil / Patrón espacial de exposición ambiental al estaño en las proximidades de una industria de aleación en Volta Redonda, estado de Río de Janeiro, Brasil

Abstract: Despite being widely used in industry, the literature on tin and its effects in humans is scarce, especially regarding reference values in biological indicators such as blood and urine. Similarly, environmental limits are also rare. This study sought to assess the spatial distribution of hotspots in the environmental exposure to tin in the vicinity of an alloy industry in the south region of the state of Rio de Janeiro, Brazil. The study population consisted of 74 adults. Graphite furnace atomic absorption spectrometry determined tin in all samples. Households and points around the industry were georeferenced with the use of GPS to identify the most intense tin sites. Results of the first and second campaigns ranged from 0.022 to 0.153 and 0.003 to 0.445µg m-3 for the atmospheric air, whereas such ranges were 0.64 to 1.61 and 1.97 to 8.54µg m-2 for household dust, respectively. The mean tin concentration found in the blood of the population was 3.85 ± 1.57µg L-1. In urine the value was 3.56 ± 1.88µg L-1. The kernel map showed the highest spatial concentrations of tin in household dust in the eastern region of the industry. In the first sampling, atmospheric air samples presented the most elevated concentrations in the southwest and southeast. Although the direction of the wind was northwest, potentially high risks were concentrated in the central area in the second collection. The largest hotspots were in the north, south and southeast regions; however, urine samples showed medium to high levels in the west and east regions. Regarding blood samples, the greatest difference was the absence of hotspot areas in the west. Environmental monitoring becomes necessary to better assess the exposure to tin.

Resumo: O estanho é amplamente utilizado na indústria. A literatura sobre seus efeitos em humanos é escassa, principalmente quanto aos valores de referência em indicadores biológicos como sangue e urina. Também são raros os estudos sobre os limites do estanho no meio ambiente. O estudo teve como objetivo avaliar os pontos críticos da distribuição espacial da exposição ambiental ao estanho nos arredores de uma indústria de ligas metálicas na região sul do Estado do Rio de Janeiro, Brasil. A população do estudo consistiu em 74 adultos. O estanho foi medido em todas as amostras com a espectrometria de absorção atômica em forno de grafite. As residências e outros pontos em torno da indústria foram georreferenciados com GPS para identificar os locais com maior concentração de estanho. Os resultados da primeira e segunda campanhas variaram entre 0,022 e 0,153 e entre 0,003 e 0,445µg m-3 para o ar atmosférico, enquanto para a poeira doméstica as faixas foram 0,64-1,61 e 1,97-8,54µg m-2, respectivamente. A concentração sanguínea média de estanho na população foi 385 ± 1,57µg L-1 e na urina foi 3,56 ± 1,88µg L-1. O mapa kernel mostrou as concentrações mais elevadas de estanho na poeira doméstica nos arredores ao leste da indústria. Na primeira amostragem, o ar atmosférico apresentou as concentrações ao sudoeste e sudeste da fábrica. Entretanto, riscos potencialmente altos estiveram concentrados na área central, embora a direção do vento tenha sido noroeste na segunda coleta de amostras. Os maiores pontos críticos foram ao norte, sul e sudeste da indústria, mas as amostras de urina mostraram níveis moderados a altos ao oeste a ao leste. Nas amostras de sangue, a maior diferença foi a ausência de pontos críticos ao oeste da indústria. O monitoramento ambiental é necessário para melhor avaliar a exposição ao estanho.

Resumen: El uso del estaño está muy generalizado en la industria. La literatura sobre sus efectos en humanos es escasa, especialmente en lo que concierne a los valores de referencia en indicadores biológicos como sangre y orina. Igualmente, los límites ambientales también son raros. El objetivo de este estudio fue evaluar los puntos calientes de la distribución espacial de exposición ambiental al estaño, en las proximidades de una industria de aleación, en el sur del estado de Río de Janeiro, Brasil. El estudio poblacional contó con 74 adultos. La espectrometría de absorción atómica por horno de grafito halló estaño en todas las muestras. Asimismo, las residencias se georreferenciaron con puntos alrededor de la industria mediante GPS para identificar los lugares con mayor intensidad de estaño. Los resultados de la primera y segunda campaña oscilaron de 0,022 a 0,153 y 0,003 a 0,445µg m-3 en aire atmosférico, aunque tales rangos fueron de 0,64 a 1,61 y de 1,97 a 8,54µg m-2 en el caso de polvo doméstico, respectivamente. El promedio de concentración de estaño encontrado en la sangre de la población fue 3.85 ± 1.57µg L-1. Respecto a la orina, este valor fue 3.56 ± 1.88µg L-1. El mapa de kernel expuso que las concentraciones espaciales más altas de estaño en el polvo doméstico de las casas se encontraron en la región oriental de la industria. En la primera muestra, las muestras de aire atmosférico presentaron las concentraciones más elevadas en el suroeste y sureste. No obstante, los riesgos potencialmente altos se concentraron en el área central, a pesar de que la dirección del viento era noroeste en la segunda recogida de muestras. Los puntos calientes más grandes estuvieron en el norte, sur, y sureste. Sin embargo, las muestras de orina mostraron niveles de medios a altos en el oeste y este. Respecto a las muestras de sangre, la diferencia más grande fue la ausencia de áreas calientes en el oeste. El monitoreo ambiental se hace necesario para evaluar mejor la exposición al estaño.