Which mold spore size is most likely to be inhaled by humans?

The correct choice is less than 5 microns because spores of this size are small enough to remain airborne for extended periods and can easily be inhaled into the respiratory system. When mold spores are less than 5 microns, they can penetrate deeper into the lungs, increasing the likelihood of respiratory issues and other health problems. This size range is critical in terms of health risk assessment and remediation strategies because the smaller the spore, the more readily it can be inhaled without being trapped by the upper respiratory tract.

Understanding the dynamics of spore sizes and their potential for inhalation is important in the context of microbial remediation. Larger spores, such as those in the 20-30 micron range or even 10-15 microns, are more likely to settle out of the air due to their weight and are typically filtered out by the body's natural defenses before reaching the lower airways. Therefore, effective mitigation strategies must prioritize addressing spores that are less than 5 microns in size to minimize health risks associated with mold exposure.