This study includes the temporal analysis of the levels of NO2, CO, and ground-level O3 measured in Lima Metropolitana between the years 2015 to 2018 and the relationship between them and with air temperature and solar radiation. For this, descriptive, correlational, and regression temporal analyzes were carried out using hourly records taken in different areas of the city. The levels of the gases evaluated were mainly below the Peruvian regulations and the World Health Organization's air quality guidelines, so their influence on the health of the population was not relevant. The hourly levels of these gases were bimodal and were influenced by vehicular traffic for NO2 and CO, and by solar radiation for ground-level O3; although, the latter may also have been influenced by its nocturnal movement. Daily behavior showed the so-called "weekend effect". The correlation analysis indicated a h...

The SARS-CoV-2 pandemic involved a set of restriction measures in order to guarantee social distancing. Consequently, these measures altered the environmental conditions in the areas where they were applied. The temporal variation of particulate matter of 2.5 microns in diameter or less (PM2.5) concentrations was evaluated in two cities by this study: Metropolitan Lima and Arequipa in the years 2019 – 2021. To carry it out, PM2.5 concentrations data from the National Service of Meteorology and Hidrology (SENAMHI by its acronym in Spanish) for Metropolitan Lima city and PM2.5 concentrations data from the Regional Directorate of Environmental Health (DIRESA by its acronym in Spanish) of Arequipa for Arequipa city were used. The results showed that in general the concentrations of PM2.5 decreased in the year 2020 because of the social distancing measures adopted by the government and incr...