What size particulate is capable of penetrating deep into the lungs?

The correct answer highlights the importance of understanding how particulate matter behaves in relation to human respiratory health. Particulates that are less than 5 microns in size are small enough to bypass the body's natural defense mechanisms in the upper respiratory system, such as nasal hairs and mucus, which filter larger particles. Once inhaled, particles of this size can reach the lower regions of the lungs, specifically the bronchioles and alveoli, where they have the potential to cause respiratory issues due to their ability to penetrate deep into the lung tissue.

In contrast, larger particles, such as those that are 10 microns or more, are generally trapped in the upper airways, significantly reducing their chances of penetrating deep into the lungs. Particulates smaller than 1 micron, while they can reach deep into the lungs, are not as commonly referenced in many standards and discussions as those under 5 microns when considering the risk in typical mold remediation scenarios. Understanding the sizes of particulate matter is crucial in mold remediation and air quality assessments, as it helps in determining effective protective measures and remediation strategies.