Bronze sculptures, especially those displayed outdoors, are vulnerable to damage from pollution and acid rain. To preserve their beauty and longevity, several protective measures can be implemented.

1. Apply Protective Coatings: Wax or lacquer coatings create a barrier against pollutants and moisture. Microcrystalline wax is particularly effective, as it penetrates the surface and repels water. For long-term protection, consider specialized anti-corrosion coatings like Incralac.

2. Regular Cleaning: Gently clean sculptures with distilled water and a soft brush to remove acidic deposits. Avoid harsh chemicals, which can strip the patina. For stubborn stains, use a pH-neutral cleaner.

3. Patina Maintenance: A stable patina naturally protects bronze. If the patina degrades, consult a conservator to reapply it using controlled chemical processes.

4. Shelter or Covering: Where possible, relocate sculptures to sheltered areas or use breathable covers during heavy pollution or rain events.

5. Environmental Monitoring: Install sensors to track air quality and humidity levels near the sculpture, allowing for timely interventions.

By combining these methods, bronze sculptures can withstand environmental threats while retaining their artistic and historical value. Regular inspections by conservation experts are also recommended to address early signs of damage.