Why is there a concern about copper smelting plants?

1. They may release lethal quantities of carbon monoxide into environment.
2. The copper slag can cause the leaching of some heavy metals into environment.
3. They may release sulphur dioxide as a pollutant.

Select the correct answer using the code given below.

[UPSC Civil Services Exam – 2021 Prelims]

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (b)        

Explanation:

• Statement 1 is incorrect as copper smelting process does not release a lethal amount of carbon monoxide in the environment. Instead, during the process, carbon (C) reacts with oxygen (O2) in the air to produce carbon monoxide (CO), which then reacts with the ore and releases carbon dioxide, removing one of its oxygen atoms.
• Statement 2 is correct, as copper smelters emit high levels of toxic pollutants such as lead, arsenic, and selenium, which can contaminate the environment downstream and downwind.
• Statement 3 is correct, as copper smelters are the primary sources of sulphur oxides (SOx) and trace elements in the environment. The suspended particles can cause pollution up to 2-3 km, while sulphur dioxide can spread up to 15 km.