UPSC Prelims 2024 Q22: Chewing Gum Base and Plastic Pollution
Consider the following statements:
Statement-I:
Many chewing gums found in the market are considered a source of environmental pollution.
Statement-II:
Many chewing gums contain plastic as gum base.
Which one of the following is correct in respect of the above statements?
- Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
- Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
- Statement-I is correct, but Statement-II is incorrect
- Statement-I is incorrect, but Statement-II is correct
Answer: (a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
Statement-wise explanation
- Statement-I: correct — Gum is chewed but not swallowed, and most of it is spat out. It sticks to pavements, floors and seats, does not break down in normal outdoor conditions, and costs a lot to remove. Its gum base does not dissolve in saliva or water and resists biodegradation, so it stays in the environment as persistent litter.
- Statement-II: correct — After World War II, synthetic rubbers, waxes and plastics almost entirely replaced chicle, the natural latex of the sapodilla tree (Manilkara zapota), as the base of chewing gum. The US food regulation on chewing gum base (21 CFR 172.615) lists synthetic polymers such as polyvinyl acetate, polyethylene, polyisobutylene, butyl rubber and butadiene-styrene rubber as permitted gum-base materials. Polyethylene and polyvinyl acetate are plastics. This statement explains Statement-I: gum pollutes because its plastic base does not biodegrade.
How to eliminate
This question mostly needs the fact itself, but everyday knowledge narrows it. Statement-I is close to common sense: chewed gum stuck on roads and under desks is visible litter that does not rot away. That rules out the option that calls Statement-I incorrect. The real test is Statement-II. Remember that modern gum base is mostly synthetic polymers (polyvinyl acetate, polyethylene, polyisobutylene, synthetic rubbers), not natural chicle. Statement-II also uses the hedge 'many', not 'all', which makes it easier to accept. Once both statements are correct, ask whether II is the reason for I. Why does gum persist in the environment? Because its base is a non-biodegradable plastic. That causal link answers the question.
Know more
What is in a stick of gum? Chewing gum has two parts. The water-soluble part (sweeteners, flavours, softeners) dissolves while you chew. The insoluble gum base is what stays in your mouth and is later spat out.
From tree latex to plastic. Gum was first made from chicle, the coagulated latex of the sapodilla tree of Central America. From the 1940s it was largely replaced by synthetic materials. Natural chicle was scarce, costly and uneven in quality, while demand kept rising.
| Gum-base material | Type | Biodegradable? |
|---|---|---|
| Chicle (sapodilla latex) | Natural latex | Yes, slowly |
| Polyvinyl acetate | Synthetic resin (plastic) | No |
| Polyethylene | Plastic | No |
| Polyisobutylene, butyl rubber | Synthetic elastomers | No |
| Butadiene-styrene rubber | Synthetic rubber | No |
| Paraffin, petroleum wax | Petroleum-derived waxes | No |
Why it is a pollution issue: these polymers are hydrophobic and do not dissolve in saliva or water. Discarded gum stays sticky, sticks to surfaces and resists microbial breakdown. Over time it can break into smaller fragments, so it adds to the wider plastic and microplastic load.
Policy link for India: under the Plastic Waste Management Rules, identified single-use plastic items with low utility and high littering potential have been banned since 1 July 2022. Chewing gum is not on that list. Its plastic content is 'hidden' inside a food product, which is why questions like this one test whether you know where plastics actually turn up.
Related 'hidden plastic' examples UPSC likes: microbeads in cosmetics, synthetic fibres shed from clothes, tyre-wear particles and cigarette filters (cellulose acetate).
In the news
Plastic pollution was a major global story before the 2024 exam. UN talks on a legally binding global plastics treaty held their fourth session (INC-4) in Ottawa from 23 to 29 April 2024. That pushed attention towards less obvious sources of plastic, such as gum base.
NCERT Concepts to Revise
- Microplastics: Discarded gum base can fragment over time, so knowing what counts as a microplastic (under 5 mm) helps judge gum's environmental impact.
- Single-use plastic ban: Shows which plastic items India has banned outright, which helps you see why plastic hidden inside products like gum is a separate issue.