Air pollution can be due to natural causes or due to the influence of people

Air pollution can be due to natural causes or due to the influence of people (anthropogenic causes). Natural causes include gases and particles from volcanic eruptions, marsh gases, and gas accumulations in mines or caves. Also, forest fires of natural origin emit polluting particles. Air pollution from viruses, bacteria, fungal spores, and pollen grains can be natural or man-made. As for anthropogenic causes, gas emissions from motor vehicle traffic and industrial activity are distinguished. Similarly, the burning of fossil fuels for heating and fires of man-made origin (forest and waste).