Analysis of dengue cases using geographic information systems: Evidence from Baguio City, Philippines

@#Dengue is a global health issue and is also regarded as one of the major public health concerns in the Philippines. Presented in this paper is the application of a geographic information system (GIS) in mapping dengue cases in Baguio City. A descriptive research design was utilized and mapped dengue cases were reconciled with environmental correlates such as land cover, housing information (independent, mixed, or interconnected), hydrology (water bodies and canals), urbanization level (urban or rural), elevation, soil, and land surface temperature. Moreover, demographic factors and practices were utilized for further analysis. Results show that interconnected housing, urbanization, land surface temperature, hydrology, and population density are predictors of dengue cases in Baguio City with the predictive power of 0.3810 (strong), 0.3426 (strong), 0.2509 (medium), 0.1675 (medium), and 0.1323 (medium), respectively. In the context of dengue, several data gaps in health information systems exist. Although the Manual of Procedures for the Philippine Integrated Disease Surveillance and Response (PIDSR) published by the Department of Health (DOH) of 2014 provides a detailed guide in the management and surveillance of communicable disease, the use of GIS was noted to be unspecified. Using GIS provides the possibility of harmonizing several data sets to better inform policymakers.

Bioinformatics analysis of key toxicity pathways in the mode of action of oral exposure to hexavalent chromium / 环境与职业医学

Background Oral exposure to hexavalent chromium [Cr(VI)] can lead to gastrointestinal tumorigenesis in mice, and the mechanism is not yet clear. To predict health risk due to chemical exposure, data mining and computational toxicology analysis has become an important tool in toxicology research, which can help to elucidate mode of action (MOA) and identify key toxicity pathways. Objective This study aims to identify and evaluate key events in the MOA of oral Cr(VI) exposure. Methods Gene sets established from Comparative Toxicogenomics Database (CTD) and Gene Expression Omnibus (GEO) respectively were imported into Ingenuity® Pathway Analysis (IPA) software for pathway enrichment analysis and biological function analysis to identify potential key toxicity pathways of target organs/tissues toxicity of oral exposure to Cr(Ⅵ). Next, the weight of evidence (WOE) of the identified key toxicity pathways in the MOA of oral exposure to Cr(VI) was evaluated based on the modified Bradford Hill principle. Results A total of 54 pieces of literature related to oral Cr(VI) exposure were screened in CTD, among which 18 and 9 were related to liver and intestine with 125 and 272 corresponding genes, respectively. The pathway enrichment and biological function analysis results showed that liver and intestinal perturbation pathways were mainly related to cell stress and injury, cell cycle regulation, and apoptosis, indicating that Nrf2 pathway and AHR pathway might be the key toxicity pathways involved in the cytotoxic-mediated MOA. Meanwhile, the dose (≥170 mg·L−1 sodium dichromate) and the time point (90 d) of the activation of Nrf2 pathway was similar to the emergence of crypt cell proliferation. It was proposed that Nrf2 pathway activation might be a key event for cytotoxic-mediated MOA of small intestinal tumors. The WOE results showed moderate validity of evidence in this hypothesis, with high validity of evidence for biological plausibility and dose-response manner. Conclusion Nrf2 pathway activation might be the key event in the cytotoxic-mediated MOA of small intestinal tumors induced by oral exposure to Cr(VI) via initiating or maintaining crypt cell proliferation.

Children′s non-carcinogenic health risk assessment of heavy metals exposure to residential indoor dust around an e-waste dismantling area in South China / 中华预防医学杂志

Objective@#To evaluate the non-carcinogenic health risk of heavy metals (As, Cd, Cr, Cu, Mn, Pb and Zn) in residential indoor dust for young children around an e-waste dismantling area in South China.@*Methods@#A village around an e-waste dismantling area in South China was selected as a research site in October 2016. Convenience sampling method was used to select 36 houses in the village and 36 dust samples were collected by vacuum cleaner. The concentrations of heavy metals (Cd, Cr, Cu, Mn, Pb and Zn) in each sample were determined and expressed by the average value. Non-carcinogenic health risk assessment was conducted using the US Environmental Protection Agency (EPA) Health Risk Assessment (HRA) model, the American Toxicology and Disease Registry (ATSDR) Target-organ Toxicity Dose (TTD) approach and the ATSDR Binary Weight-of-Evidence (BINWOE) model.@*Results@#The mean ± SD of concentrations of As, Cd, Cr, Cu, Mn, Pb and Zn were (48.90±33.91), (5.95±3.89), (173.57±580.37), (412.71±1 190.00), (612.82±540.70), (297.41±293.22) and (1 052.81±1 156.48) mg/kg, respectively. The HI value of TTD (2.670) and BINWOE (2.933) were higher than the safety threshold of EPA recommended non-carcinogenic health risk. The HI value of TTD and BINWOE were 1.93 and 2.12 times higher than the HI value of HRA (1.386).@*Conclusion@#There was non-carcinogenic health risk of heavy metals (As, Cd, Cr, Cu, Mn, Pb and Zn) via residential indoor dust around the e-waste dismantling area for local children.

Integrating cheiical and biological status assesment: assembling lines of eviddence for the evaluation of river ecosystem risk / Integrando el estado químico y biológico: reunión de diversas líneas de evidencia para la evaluación del riesgo en el ecosistema fluvial

This paper describes various approaches to evaluating ecological risk in rivers affected by multiple chemical stressors, with emphasis on biofilm and invertebrate community responses. Metrics should be considered as different lines of evidence that, when weighted, form an advanced weight of evidence approach to establishing the environmental risk on a basin scale. Combination of field surveys to obtain observational data of communities, in situ experiments, toxicological sediment tests and a good chemical description of the medium (water and sediment) helps give an integrative view of the chemical and biological state of a river ecosystem. The greater and more distinct the variables used, the greater is our ability to identify the effects of major stressors impairing communities. Weight of evidence is an integrative methodology for tackling the challenge of determining causal relations and applying this knowledge in the decision-making processes of river management.

Este trabajo describe diferentes aproximaciones para la evaluación del riesgo ecológico en ríos afectados por múltiple contaminación química, con énfasis en la respuesta de las comunidades del biofilm e invertebrados bentónicos. Las métricas descritas se considerarían como diferentes líneas de evidencia que convenientemente ponderadas formarían un sistema de decisión (weight of evidence) para establecer el riesgo ambiental a escala de cuenca. La combinación de trabajo de campo para obtener datos de la comunidad biológica, experimentos in situ, test de exposición en sedimentos, y una buena caracterización química del medio (agua y sedimento), ayuda a tener un resultado integrado del estado biológico y químico del ecosistema fluvial. Cuantas más variables se incorporen, mejor se identificarán los efectos de las presiones químicas en el deterioro de la comunidad. Esta es una metodología integradora que permite abordar el reto de determinar las relaciones causales y aplicar este conocimiento en el proceso de toma de decisión en la gestión de las cuencas fluviales.

Using systematic reviews and meta-analyses to support regulatory decision making for neurotoxicants: lessons learned from a case study of PCBs / Utilizando revisões sistemáticas e meta-análise de apoio às decisões regulatórias para neurotóxicos: lições de um estudo de caso dos PCBs

We examined prospective cohort studies evaluating the relation between prenatal and neonatal exposure to polychlorinated biphenyls (PCBs) and neurodevelopment in children to assess the feasibility of conducting a meta-analysis to support decision making. We described studies in terms of exposure and end point categorization, statistical analysis, and reporting of results. We used this evaluation to assess the feasibility of grouping studies into reasonably uniform categories. The most consistently used tests included Brazelton's Neonatal Behavioral Assessment Scale, the neurologic optimality score in the neonatal period, the Bayley Scales of Infant Development at 5-8months of age, and the McCarthy Scales of Children's Abilities in 5-year-olds. Despite administering the same tests at similar ages, the studies were too dissimilar to allow a meaningful quantitative examination of outcomes across cohorts. These analyses indicate that our ability to conduct weight-of-evidence assessments of the epidemiologic literature on neurotoxicants may be limited, even in the presence of multiple studies, if the available study methods, data analysis, and reporting lack comparability.

Foram examinados estudos de grupo que avaliaram a relação entre a exposição pré-natal e neonatal aos bifenilos policlorados (PCB) e o desenvolvimento neuropsicomotor em crianças a fim de avaliar a viabilidade da realização de uma meta-análise para suporte à tomada de decisão. Nós descrevemos os estudos em termos de exposição, categorizações, análise estatística e elaboração de relatórios de resultados. Nós utilizamos esta avaliação para verificar a viabilidade de agrupar os estudos em categorias razoavelmente uniformes. Os testes mais utilizados foram Brazelton Neonatal Behavioral Assessment Scale, a pontuação de otimalidade neurológica no período neonatal, as Escalas Bayley de Desenvolvimento Infantil de 5 a 8 meses de idade, e as Escalas McCarthy de habilidades das crianças em 5 anos de idade. Apesar de administrar os mesmos testes com idades semelhantes, os estudos foram muito diferentes para permitir uma análise quantitativa significativa dos resultados entre grupos. Estas análises indicam que a nossa capacidade de realizar avaliações da literatura epidemiológica sobre neurotóxicos pode ser limitada - mesmo na presença de vários estudos - se não existe nenhuma forma de comparação com os métodos de estudo disponíveis e análise dos dados.