Banca de QUALIFICAÇÃO: FRANCISCO IVAM CASTRO DO NASCIMENTO

Socioeconomic variables, air pollution and Covid-19 in the state of Rondonia: a space-temporal

 Spatial analysis; Rondônia; Pandemic.

Recent studies suggest that there are geostatistical relationships between Covid-19 cases and deaths and environmental and socioeconomic variables. These studies are concentrated in North America, Europe and Asia, and to a lesser extent in South America, a fact that motivated the investigation of this topic considering the specificities of the Amazon region. In this context, this research aimed to understand the spatial relationship between Covid-19 cases and deaths and environmental and socioeconomic variables in the state of Rondônia between 2020 and 2023. ArcGIS, QGIS, GeoDa and R statistical software were used to assess the correlation between the variables. The statistical tests involved the application of Pearson's correlation coefficient, Ordinary Least Squares (OLS) regression test, Geographical Weighted Regression (GWR), Moran's I Univariate and Bivariate. Pearson's correlation between the rate of Covid-19 cases and deaths and the environmental variables analyzed pointed to a weak correlation in 2020 and 2021. In 2020, only nitrogen dioxide had a positive correlation with the Covid-19 case rate (p-value 0.32) and in 2021 it had a p-value -0.62. With regard to the death rate and environmental variables, in 2020 NO2 had a p-value of 0.31 and SO2 had a p-value of -0.23. In 2021, CO and NO2 had p-values of -0.45 and -0.54 respectively, showing a moderate inverse correlation. The models analyzed (GWR and OLS) had probability and adjusted R-squared with a p-value > 0.05. These results were reinforced by the application of the Koenker (BP), Jarque-Bera tests and the autocorrelation of the residuals from the Ordinary Least Squares (OLS) regression test for the rate of cases and deaths from Covid-19 in 2020 and 2021, indicating low spatial correlation between the dependent and independent variables. With regard to socio-economic variables, this maintained a significant correlation (R² above 0.5) for both cases and deaths from Covid-19 in the first epidemiological weeks, decreasing throughout 2020. In 2021 and 2022, the correlation analysis does not indicate a significant association between the variables analyzed and Covid-19 cases and deaths. There was also a time lag between contact with the virus, becoming ill and being tested. In addition, studies analyzing the effect of air pollution on health point to a time lag of a few days between the critical episode of pollution and hospital admission and death. However, in Rondônia, the opposite occurred, with an increase in Covid-19 cases and deaths before the increase in pollution levels, which may have contributed to the lack of correlation found.