I did not knew the answer hence I checked on the Wikipedia, from same I found: “Mold is found everywhere and can grow on almost any substance when moisture is present. They reproduce by spores, which are carried by air currents. When spores land on a moist surface suitable for life, they begin to grow. Mold is normally found indoors at levels which do not affect most healthy individuals.”
And I guess depending on the weather their concentration and growth can vary, and further they can lead to few minor health problems, such as cold, respiratory issues when the weather changes.
jboyle commented on :
thank so much for answering