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Lead exposure is a severe public health issue that can adversely affect children's neurocognitive development. A semi-urban community in Mexico has been exposed to lead from food cooked in glazed clay pots. A cognitive intervention was conducted from 2015 to 2016 to minimize this negative impact. This intervention aimed to improve the neurocognitive development of the affected children. METHODS: A quasi-experimental study with a control group was conducted in children aged 7 to 12 years from 2 communities in Morelos, Mexico. Blood lead levels were determined, and the neurocognitive function was assessed pre- and postintervention with the Wechsler Intelligence Scale for Children and Children's Auditory Verbal Learning Test-2. A cognitive intervention was conducted at the school. The difference-in-differences method adjusted for variables known as priori and evaluated the impact of cognitive intervention. RESULTS: The differences-in-differences models indicated a significant average increase in scores on the Verbal Comprehension Index (9.58 points), Processing Speed Index (5.33 points), intelligence quotient (5.63 points) level of learning (7.66 points), interference trial (10.12 points), immediate memory span (7.98 points), and recognition accuracy (1.18 points) subtests after the cognitive intervention. CONCLUSION: The results suggest that cognitive intervention improves neurocognitive development in schoolchildren exposed to Pb.

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Long-term research has identified significant water contamination and associated poor health outcomes in the indigenous community of Alpuyeca, located in south-central Mexico. We set out to develop a popular education initiative in this community to improve water, sanitation and hygiene (WaSH) knowledge and practices. In order to avoid recreating hierarchical power dynamics in this vulnerable community, a participatory action research (PAR) design was used, wherein the community took leadership and facilitation roles in each stage of the research process. In qualitative interviews and design sessions, community members identified unsatisfied WaSH needs in households and community institutions and articulated a clear worldview of the spiritual role of water, which guided the development of a series of popular education-based workshops and discussions. The popular education initiative process was documented with a mixed methods framework, using before-and-after surveys, semi-structured interviews and participatory observation. Increases in knowledge and practices related to water purification, water consumption and hand hygiene were noted in the community. The community identified locally installed and managed ecotechnologies as a key opportunity for sustainable development, community participation and the adoption of water and sanitation systems, compatible with public imaginaries of the role of water.

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Water fluoride levels above the World Health Organization's guideline (1.5 mg/L), common in overexploited aquifers, represent a health hazard. Our objective was to assess the health risks posed by exposure to fluoride in different drinking water sources in a contaminated basin in Mexico. Fluoride was measured in mutual drinking water sources and in the urine of 39 children and women. Risks were estimated through hazard quotient (HQ) by drinking water source. Dental fluorosis was assessed in the children. Mean fluoride water concentrations (mg/L) were: well, 4.2; waterhole, 2.7; bottled, 2.1; rainwater, 0.4. The mean urinary fluoride concentrations (specific gravity adjusted) were 2.1 mg/L and 3.2 mg/L in children and women, respectively. Our multiple linear regression model showed children's urinary fluoride concentrations increased 0.96 mg/L for every 1 mg/L increase in water fluoride (p < 0.001). Dental fluorosis was diagnosed in 82% of the children, and their HQ according to drinking water source was: well, 1.5; waterhole, 1.1; bottled, 0.8; harvested rainwater, 0.3. The pervasive dental fluorosis indicates a toxic past fluoride exposure; urinary fluoride levels and HQs indicate high exposure and current health risks for most children. Drinking harvested rainwater will likely prevent most of the local fluoride exposure.

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Resumen: Objetivo: Analizar la asociación entre la exposición crónica a contaminantes atmosféricos y la tasa de mortalidad por Covid-19 en ciudades mexicanas. Material y métodos: Estudio ecológico en 25 ciudades mexicanas utilizando el reporte de casos diarios de muertes por Covid-19 (febrero a junio 2020) y datos validados de contaminantes atmosféricos, considerando concentraciones promedio en cada ciudad en el último año. Se utilizaron modelos de regresión Poisson, con modelos aditivos generalizados y variables de ajuste. Resultados: Se encontró un incremento significativo de 3.5% (IC95% 2.3-4.7) en la tasa de mortalidad por Covid-19 por incremento de 1µg/m3 de NO2. La asociación con PM2.5 fue no significativa, con un incremento de 1.8% por cada µg/m3. Conclusiones: Los resultados sugieren una asociación entre la mortalidad por Covid-19 y la exposición a NO2. Esta primera aproximación del riesgo asociado con la contaminación del aire requiere de análisis más precisos, pero es consistente con estudios de otras regiones.

Abstract Objective: To analyze the relationship between chronic exposures to air pollution with Covid-19 death rate in Mexican cities. Materials and methods: Ecological study in 25 Mexican cities using the report of daily Covid-19 deaths (from February to June 2020) and validated data of air pollutants, considering average concentrations in each city for the last year. Poisson regression models using generalized additive models with adjustment variables (GAM) were used. Results: A significant increase of 3.5% (95% CI 2.3-4.7) was found in Covid-19 death rate for each 1µg/m3 in annual concentration of NO2. The association with PM2.5 was not significant, with an increase of 1.8% for each 1µg/m3. Conclusions: Results suggest an association between Covid-19 mortality and chronic exposure to NO2. This first approximation of the risk associated with air pollution requires a more precise analysis, but is consistent with what was observed in other studies.

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Objetivo. Analizar la asociación entre la exposición crónica a contaminantes atmosféricos y la tasa de mortalidad por Covid-19 en ciudades mexicanas. Material y métodos. Estudio ecológico en 25 ciudades mexicanas utilizando el reporte de casos diarios de muertes por Covid-19 (febrero a junio 2020) y datos validados de contaminantes atmosféricos, considerando concentraciones promedio en cada ciudad en el último año. Se utilizaron modelos de regresión Poisson, con modelos aditivos generalizados y variables de ajuste. Resultados. Se encontró un incremento significativo de 3.5% (IC95% 2.3-4.7) en la tasa de mortalidad por Covid-19 por incremento de 1µg/m3 de NO2. La asociación con PM2.5 fue no significativa, con un incremento de 1.8% por cada µg/ m3. Conclusiones. Los resultados sugieren una asociación entre la mortalidad por Covid-19 y la exposición a NO2. Esta primera aproximación del riesgo asociado con la contami-nación del aire requiere de análisis más precisos, pero es consistente con estudios de otras regiones.

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Objective. To analyze the relationship between chronic exposures to air pollution with Covid-19 death rate in Mexican cities. Materials and methods. Ecological study in 25 Mexican cities using the report of daily Covid-19 deaths (from February to June 2020) and validated data of air pollutants, considering average concentrations in each city for the last year. Poisson regression models using generalized additive models with adjustment variables (GAM) were used. Results. A significant increase of 3.5% (95% CI 2.3-4.7) was found in Covid-19 death rate for each 1µg/m3 in annual concentration of NO2. The association with PM2.5 was not significant, with an increase of 1.8% for each 1µg/m3. Conclusions. Results suggest an association between Covid-19 mortality and chronic exposure to NO2. This first approximation of the risk associated with air pollution requires a more precise analysis, but is consistent with what was observed in other studies.

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Entangled in complex ecological, sociocultural, and economic systems, current environmental health problems require integrated participatory approaches. Alpuyeca, a semi-urban, highly marginalized community in South-Central Mexico burdened by lead and polychlorinated biphenyl (PCB) contamination, dengue fever, and intestinal diseases, illustrates this. Its residents are distinctive, however, for their concerted actions in the face of environmental problems and the presence of defenders of a prehispanic worldview based on the protection of nature. This article addresses the health impacts of an integrated environmental health promotion strategy implemented through a participatory action research intervention based on qualitative and quantitative methods. Different actors, sectors, dimensions, and knowledge types were harmonized in a collaborative space created specifically for our interdisciplinary research team, community residents and local authorities. Reflections, plans and actions were developed collectively in this space with the view of finding solutions anchored in the local culture. Results included sharp reductions in blood-lead concentrations among children, in entomological indices, and in PCB contamination, as well as capacity strengthening. Medium-level community participation was achieved. This work contributes evidence that participatory environmental health research can be effective in analyzing and reducing problems in communities with multiple environmental health concerns. It complements ecohealth and environmental health literacy approaches.

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The aim of this pilot study was to evaluate the link between housing and children´s respiratory symptoms, through the construction of an index (HSHI) based on the definition of healthy-sustainable housing criteria, in a semi-urban community from Morelos, Mexico. A general and household questionnaire, and respiratory symptoms diary were applied in 60 households to gather information about schoolchildren, respiratory health, housing and lifestyle characteristics. HSHI was constructed using principal component analysis. The association between HSHI and the presence and duration of respiratory symptoms was assessed using logistic and Poisson regression models. HSHI had five components, which accounted for 63% of variance, and were classified into poor and sufficient quality. It was observed that schoolchildren who inhabit a sufficient-quality house, showed a reduction in nose irritation duration and in the allergic symptoms probability regarding component 1 (ventilation, lighting and cloth washing) and presented three times less duration of common cold by component 2 (construction material, painted walls inside the house and type of bathroom) compared to poor-quality house inhabitants. Our results suggest that living in a sufficient-quality house, as described by the HSHI, reduced the prevalence of wheezing episodes and the probability of ear pain, providing evidence about the positive association of a healthy-sustainable housing on the respiratory health of schoolchildren.

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Airborne manganese (Mn) is considered the most hazardous route of exposure since Mn particles can enter into the body through the lung and may access the brain directly through olfactory uptake, thereby bypassing homeostatic excretory mechanisms. Environmental indoor and outdoor manganese concentrations in PM2.5 were monitored in ten rural households from two communities of Hidalgo, Mexico, from 2006 to 2007. Indoor and outdoor air samples of PM2.5 were collected using MiniVol samplers, and Mn concentrations in the filters were measured using proton-induced X-ray emission (PIXE). An adjusted generalized linear mixed model was applied and then used for estimating indoor concentrations in non-monitored households. Our monitoring results showed a higher daily average concentration of indoor PM2.5 vs. outdoor PM2.5 (46.4 vs. 36.2 µg/m(3), respectively); however, manganese concentration in PM2.5 indoor and outdoor was 0.09 µg/m(3) in both sceneries. Predictor variables of indoor Mn concentration were outdoor Mn concentration (64.5% increase per 0.1 µg/m(3) change in Mn) and keeping the windows open (4.2% increase). Using these predictors, the average estimated indoor Mn concentration in PM2.5 was 0.07 µg/m(3) (SD = 0.05). Our results confirm the direct effect of outdoor Mn levels, opening house windows, and the distance to the mining chimney in indoor Mn levels in houses.

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