Detailed Explanation:

Answer: Option 2 — 2 and 3 Only

Copper smelting plants are a major environmental concern due to their emission of sulfur dioxide and the potential for heavy metal leaching from copper slag. The primary gaseous pollutant is SO₂, not carbon monoxide.

❌ Statement 1 – Incorrect: Copper smelting plants do not typically release lethal quantities of carbon monoxide; the primary gaseous pollutant of concern is sulfur dioxide (SO₂).

✅ Statement 2 – Correct: Copper slag, a byproduct of smelting, contains heavy metals like arsenic, lead, and cadmium, which can leach into soil and groundwater, causing environmental contamination.

✅ Statement 3 – Correct: Copper smelting releases large amounts of sulfur dioxide because most copper ores are sulfide minerals (like chalcopyrite), and sulfur is oxidized to SO₂ during roasting and smelting processes.

📝 Short Notes: Environmental Concerns of Copper Smelting

• Primary Pollutant: Sulfur dioxide (SO₂) is the main gaseous emission from copper smelting, as copper ores are predominantly sulfide minerals.
• Copper Slag: Contains heavy metals (arsenic, lead, cadmium, mercury) that can leach into environment, contaminating soil and water resources.
• Acid Rain: SO₂ emissions contribute to acid rain formation, damaging ecosystems, crops, and infrastructure.
• Health Impacts: SO₂ causes respiratory problems; heavy metals from slag can bioaccumulate and cause neurological and developmental issues.
• Mitigation Measures: Use of scrubbers to capture SO₂, proper slag management, adoption of cleaner smelting technologies, and recovery of sulfur for sulfuric acid production.