Which of the following pollutants is not usually recycled?

Step 1: Analyze the question The question asks which pollutant is not usually recycled. Recycling means collecting waste materials and processing them into new, useful products.

Step 2: Explain the concept Recycling is practical when a material can be safely and economically collected, reprocessed, and reused.

• Aluminium cans (A): These are melted down and reshaped into new cans or other products. This saves a great deal of energy compared with extracting aluminium from bauxite. They are widely recycled.
• Glass bottles (B): Glass can be crushed into cullet, melted, and remade into new bottles or jars. It is commonly recycled and also reused directly, as with returnable bottles.
• Paper wastes (D): Paper is pulped and made into new paper, cartons, and tissue. It is widely recycled.
• Nuclear wastes (C): These contain radioactive substances that stay hazardous for hundreds to thousands of years. They cannot be treated like ordinary waste. They are normally stored in shielded containers, buried deep underground, or kept in secure facilities. (Some spent fuel can be reprocessed in a few countries, but this is specialised, costly, and not "usual" recycling.)

Step 3: Identify the answer Aluminium, glass, and paper are routinely recycled. Nuclear waste is dangerous, radioactive, and is generally disposed of by secure storage rather than recycled.

Correct answer: C. Nuclear wastes

Exam tip: For questions about "not usually recycled", look for the option that is hazardous or radioactive. Everyday materials like metals, glass, paper, and plastics are the ones that can be recycled. Remember: "Nuclear waste is stored, not reused."