Asociación entre mortalidad por Covid-19 y contaminación atmosférica en ciudades mexicanas / Association between Covid-19 mortality and atmospheric pollution in Mexican cities

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.

Asociación entre mortalidad por Covid-19 y contaminación atmosférica en ciudades mexicanas.

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.

[Association between Covid-19 mortality and atmospheric pollution in Mexican cities]. / Asociación entre mortalidad por Covid-19 y contaminación atmosférica en ciudades mexicanas.

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.

Air Pollution and Suicide in Mexico City: A Time Series Analysis, 2000-2016.

The association between air pollution and suicide has recently been under examination, and the findings continue to be contradictory. In order to contribute evidence to this still unresolved question, the objective of the present study was to evaluate the association between air quality and daily suicides registered in Mexico City (MC) between 2000 and 2016. Air quality was measured based on exposure to particulate matter under 2.5 and 10 micrometers (µm) (PM2.5 and PM10, respectively), ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2), adjusting for weather variables (air temperature and relative humidity), and holidays. To this end, an ecologic time series analysis was performed using a Poisson regression model conditioned by time and stratified by gender and age groups. Models were also generated to explore the lagged and accumulative effects of air pollutants, adjusted by weather variables. The effects of the pollutants were very close to the null value in the majority of the models, and no accumulative effects were identified. We believe these results, in this case, no evidence of a statistical association, contribute to the current debate about whether the association between air pollution and suicide reported in the scientific literature reflects an actual effect or an uncontrolled confounding effect.