Aspergillus

What it means

Aspergillus is a group of molds found nearly everywhere. CDC lists it with Cladosporium and Penicillium as the most common indoor molds, and says its spores are common in both indoor and outdoor air.

CDC says “most people breathe in Aspergillus spores every day without getting sick.” For some people, though, the spores can cause aspergillosis, a lung infection.

Why it matters to your health

The people at highest risk of aspergillosis, according to CDC, are those with weakened immune systems or lung diseases, including people who recently had an organ or stem cell transplant. If someone in your home is in one of those groups, talk to their doctor before anyone disturbs moldy materials, and keep that person away from the work area. For everyone else, EPA says molds produce allergens and irritants that can trigger allergy symptoms or asthma attacks in sensitive people. Seeing Aspergillus on a report is not, by itself, a reason for alarm. See our page on mold symptoms for what the evidence supports.