After Hurricane Harvey hit Houston in 2017, researchers wanted to understand how people with weakened immune systems were exposed to mold. They looked at a group of immunosuppressed residents in the affected area. The study found that 49% of the people in their sample reported doing cleanup activities in homes that had water damage and mold contamination.
This was a convenience sample, meaning the researchers studied people who were available and willing to participate. This method can make it hard to know if the results apply to all immunosuppressed people in the area. The study did not report on whether any of these residents actually got sick from mold infections.
The main reason to be careful with this information is that the study only tells us about exposure—people being around mold during cleanup. It does not tell us if that exposure led to any health problems. The study also did not compare these residents to people who did not do cleanup.
Readers should take from this that mold exposure after a hurricane is a real concern for vulnerable people. However, this single, small study cannot tell us how common this behavior was overall or what the health risks were. More research would be needed to understand the full picture.