Outdoor metal sculptures face constant exposure to environmental elements that accelerate corrosion and degradation. Understanding these factors is crucial for preservation.

1. Moisture and Humidity: Water is the primary catalyst for rust, especially in iron and steel. Prolonged humidity creates electrolytic reactions, speeding up oxidation.

2. Salt Exposure: Coastal areas or winter road salt spray trigger galvanic corrosion, rapidly eating into metals like bronze or copper.

3. Air Pollution: Industrial emissions (sulfur dioxide, nitrogen oxides) form acidic compounds that corrode surfaces, while particulate matter abrades protective patinas.

4. Temperature Fluctuations: Repeated expansion/contraction from thermal cycling weakens metal structures and cracks protective coatings.

5. Biological Growth: Lichens, moss, and bird droppings retain moisture and secrete corrosive acids, particularly damaging to intricate details.

Preventive measures include regular cleaning, applying protective waxes, and selecting corrosion-resistant alloys like stainless steel or corten steel for outdoor installations. Strategic placement away from sprinklers or ocean spray also extends artwork longevity.

For collectors, annual inspections and immediate treatment of early rust spots are essential to combat these environmental threats effectively.