Understanding the implications of this damage depends upon understanding the nature of the damage itself.
"Ciliated" refers to cells that have hair-like structures on them, which can move and thereby transport either themselves or extracellular particles, depending on the cell and its function. "Epithelial" refers to cells that are part of the epithelium, essentially the outer layer of the body and the primary protective barrier between the body and the environment.
The respiratory tract is one of the most vulnerable portions of the body because the barrier between the interior of the body and the exterior environment is necessarily thin in order to allow the relevant gases (oxygen and carbon dioxide) to pass in and out of the body in sufficient quantities, rather than simply bouncing off or becoming trapped in one of many layers of protective epithelial lining.
One of the vulnerabilities of this system is that along with the oxygen and carbon dioxide gases, other material may enter as well; dirt, ash, bacteria, and so forth. The ciliated epithelia are one of several means of dealing with this vulnerability; their primary function is to work in coordination with a layer of mucus (protective goo-like liquid that keeps the interior of the respiratory system moist and physically insulated). The mucus is cycled out of the respiratory system via the "beating" of the cilia; think of it as being akin to a janitor continuously sweeping out garbage.
Damage to these cells could cause many negative implications; most prominently, if their ability to cycle the mucus is affected, then the individual will probably experience a buildup of mucus, possibly leading to airway obstruction, as well as an increased risk of infection or physical trauma to the airway due to foreign particles trapped in the mucus not being removed from the airway.