Chewing gum is designed for mastication without ingestion, and its most significant component is the gum base. When discarded, this base does not decompose naturally like organic materials. Due to its synthetic composition, traditional gum degrades very slowly over decades or even centuries, rather than breaking down into harmless natural elements.
The Core Components of Chewing Gum
The persistence of chewing gum in the environment is due to the chemical composition of its non-soluble component: the gum base. This base is a complex, proprietary blend designed to provide the product’s characteristic elasticity and chewiness. While gum was historically made from natural tree saps like chicle, modern commercial gums primarily rely on synthetic polymers.
These synthetic components are petroleum-derived materials, such as elastomers, resins, and waxes, similar to those found in plastics and rubbers. Common polymers include polyisobutylene, styrene-butadiene rubber, and polyvinyl acetate. Since these long-chain molecules are not digestible by the bacteria and fungi responsible for decomposition in soil, the gum base resists biological breakdown and remains intact.
How Long Does Gum Survive in the Ground?
Chewing gum does not truly decompose into organic matter but undergoes a slow process of degradation. This process is highly dependent on environmental factors like sunlight, temperature fluctuations, and moisture levels. Estimates for the total breakdown time of synthetic gum range widely, often cited between 20 to 25 years, with some projections extending this timeline up to 1,000 years.
When the gum appears to break down, it is actually fragmenting into smaller pieces. Over time, the gum base breaks down into tiny, micrometer-wide plastic particles known as microplastics. These microplastics disperse into the soil and water systems, contributing to long-term contamination.
Environmental Consequences of Gum Litter
The persistence of discarded gum creates a significant problem beyond slow degradation. Gum litter is the second most common form of litter found on streets, creating widespread aesthetic pollution. Removing this sticky residue from sidewalks and public spaces is a complex and costly endeavor for municipalities, often requiring specialized techniques.
As the gum fragments, the resulting microplastics enter the environment, posing a risk to soil health and wildlife. Animals, particularly birds, may mistake discarded gum for food, leading to potential digestive blockages. These plastic polymers contribute directly to the growing global issue of microplastic contamination.
Best Practices for Gum Disposal
Addressing the environmental challenge of gum litter requires responsible disposal practices. The proper method for disposing of used gum is to wrap it securely in paper or tissue and place it in a general waste bin. This ensures the synthetic base is contained and directed toward a landfill or incineration facility, preventing it from becoming environmental litter.
Newer, sustainable alternatives offer an eco-friendly option for consumers concerned about plastic content. These products often use natural tree saps, such as chicle, for their base, making them genuinely biodegradable. However, since the vast majority of gum sold still contains a synthetic base, conscious disposal remains the most immediate and effective action.