Are masks useful for reducing exposure to dust and smoke?

Protective dust masks and dust-filtering respirators can keep dust out of the air you inhale. For workers and volunteers working in dusty areas surrounding the devastation, exposure can be reduced by routine use of well-fitted dust masks (such as N-95 or more protective NIOSH-approved respirators available commercially).

In areas where airborne asbestos is known or suspected to be present, N/R/P100 particulate filters with elastomeric half-masks are recommended to prevent short and long-term health problems (if you don't know what these are, ask your supervisor). The respirator should fit your face. A poor fit can allow dust to bypass the dust filter, sharply reducing any protection from the mask.