It is easy to confuse mold with black dirt or dust. Dirt and dust is easily wiped off with a clean cloth.
Mold is a type of fungus that has a distinct, damp smell, needs moisture to grow, and can attach itself to walls and other vertical spaces. The smell is similar to rotting wood, wet dog, or soggy cardboard. Mold reproduces via tiny spores that spread through the air, on clothing, or on dust particles.
Dust contains dead skin cells, hair, pollen, bacteria, dead insects, and minutes traces of plastic. It settles on low surfaces as it is pulled down by gravity. It does not have the ability to attach itself to vertical surfaces. Mold can grow on dust particles.
Mold is often furry or velvety in appearance and presents a more uniform ‘growth” rather than a collection of dust particles.
Dirt is a medium for mold to grow. It has an earthy odor.