Porcelain sculptures, admired for their delicate beauty, are particularly vulnerable to damage when exposed to air pollution. The most common types of deterioration include:

1. Surface Discoloration: Pollutants like sulfur dioxide create yellow or gray stains that mar the sculpture's original luster. Acidic particles in smog chemically react with glaze components, altering colors permanently.

2. Micro-Cracking (Crazing): Temperature fluctuations combined with pollutant exposure cause fine surface cracks that weaken structural integrity. These hairline fractures often appear first in high-detail areas.

3. Material Erosion: Acid rain and particulate matter gradually eat away at unprotected surfaces, creating rough patches where intricate details become blurred or lost entirely.

4. Salt Efflorescence: Airborne salts crystallize within porous areas, creating white crusty deposits that expand and cause spalling (surface flaking).

5. Metal Component Corrosion: Any bronze or metal attachments oxidize rapidly when exposed to polluted air, leading to unsightly green patinas or complete structural failure at joining points.

Preventive measures include controlled display environments, regular professional cleaning, and protective coatings. Collectors should monitor humidity (ideally 40-50%) and filter airborne pollutants to preserve these fragile artworks. Early intervention can save historically significant pieces from irreversible damage.