Which of the following materials is classified as a non-biodegradable pollutant?

Step 1: Analyze the question We need to find the material that cannot be broken down naturally by living organisms such as bacteria and fungi. That is what "non-biodegradable" means.

Step 2: Explain the concept

• Biodegradable materials come from living things (plants and animals). Microorganisms can decompose them into simpler substances, so they do not build up in the environment.
• Non-biodegradable materials are mostly synthetic, such as plastics, polythene bags, and some metals and glass. Microorganisms have no enzymes that can break down their long, stable chemical chains, so they stay in the environment for hundreds of years and cause pollution.

Step 3: Examine each option

• A. Animal hide: This is animal tissue made of protein (collagen), so it is biodegradable. It rots over time.
• B. Paper: It is made from cellulose from plants, so it is biodegradable.
• D. Wood: It is made of cellulose and lignin, which fungi and bacteria decompose, so it is biodegradable.
• C. Plastic: It is a synthetic polymer, such as polythene or PVC. Microbes cannot easily break it down, so it is non-biodegradable.

Step 4: Answer The correct option is C. Plastic.

Exam tip: If a material comes from a plant or animal, it is usually biodegradable. If it is synthetic, such as plastic, polythene, or nylon, it is usually non-biodegradable. In Nigeria, discarded sachet water bags (pure water nylons) blocking drains are a common example of this pollution.