Pollution from before the pandemic also affected what happened after people became sick. Scientists saw that more people died from COVID-19 in places with large amounts of air pollution. One team of scientists from Martin Luther University Halle-Wittenberg looked at air pollution information from satellites and statistics on COVID-19 deaths in Italy, France, Germany and Spain and saw that places with large amounts of nitrogen dioxide pollution had more people die from COVID-19. Nitrogen dioxide can damage the lungs.