Telecommunication activity-derived public mobility indices as drivers of PM2.5 concentration in northwestern Croatia at the time of Covid-19 outbreak in the early 2020

The Covid-19 pandemic has emerged as a challenge for numerous socio-economic processes established in times prior the outbreak. Here we contribute to the subject with an analysis of the mobility pattern changes, derived from telecommunications location services data, and their effects on the air pollution with the PM2.5 particles during the imposed lockdown in Krapinsko-zagorska county (Županija krapinsko-zagorska) in the north-western Croatia in the first quarter of 2020. The study is conducted using the publicly available data. Statistical analysis reveals the complex cause-effect relationship between the PM2.5 concentration, as the measure of air quality, and the general public mobility. We continue our research to contribute to understanding of the Covid-19 epidemiological development, and the socio-economic impact on the climate change and environmental conditions