This work studied the spread of COVID-19, the meteorological conditions and the air quality in a megacity from two viewpoints: (1) the correlation between meteorological and air quality (PM₁₀ and NO₂) variables with infections and deaths due COVID-19, and (2) the improvement in air quality. Both analyses were performed for the pandemic lockdown due to COVID-19 in the City of Buenos Aires (CABA), the capital and the largest city in Argentina. Daily data from temperature, rainfall, average relative humidity, wind speed, PM₁₀, NO₂, new cases and deaths due COVID-19 were analyzed. Our findings showed a significant correlation of meteorological and air quality variables with COVID-19 cases. The highest temperature correlation occurred before the confirmation day of new cases. PM₁₀ presented the highest correlation within 13 to 15 days lag, while NO₂ within 3 to 6 days lag. Also, reductions in PM₁₀ and NO₂ were observed. This study shows that exposure to air pollution was significantly correlated with an increased risk of becoming infected and dying due to COVID-19. Thus, these results show that the NO₂ and PM₁₀ levels in CABA can serve as one of the indicators to assess vulnerability to COVID-19. In addition, decision-makers can use this information to adopt strategies to restrict human mobility during the COVID-19 pandemic and future outbreaks of similar diseases in CABA.

Introduction: Nosocomial pathogens have become a priority issue for public health, since they are responsible for increased morbidity and mortality in hospitalized patients and the development of multi-resistant microorganisms, as well. Recent studies found strong evidence that airborne transmission plays a key role in many nosocomial infections. Thus, we aim to develop a QuEChER methodology for the characterization of airborne microbial levels, analyzing potential variables that modify the air microbiological load. Methodology: Particulate matter levels and suspended and settled bioaerosols were determined simultaneously employing optical sensors, Harvard impactors and settle plates, respectively. Environmental variables were also measured at different sites during different working shifts and seasons. Results: We found a straightforward relationship between airborne particles, air exchange rates, and people influx. Levels of suspended microorganisms were related to fine particulate matter concentration, CO2 and ambient temperature. A positive linear relationship (R2 = 0.9356) was also found between fine particulate matter and CO2 levels and air microbial load. Conclusion: The QuEChER methodology is an effective methodology that could be used to improve the surveillance of nosocomial pathogens in developing countries hospitals where air quality is scarcely controlled.

MÉTODO OPTIMIZADO PARA LA DETERMINACIÓN DE HIDROCARBUROS AROMÁTICOS POLICÍCLICOS ASOCIADOS A PARTÍCULAS ATMOSFÉRICAS