Statement 1 is correct: Coal ash, a by-product of coal combustion in power plants, contains various heavy metals including arsenic, lead, and mercury. These metals can pose environmental and health hazards. These toxic elements can leach into water bodies and contaminate soil. Statement 2 is correct: The combustion of coal in power plants releases releases sulfur dioxide (SO₂), which contributes to acid rain and respiratory issues. It also emits oxides of nitrogen (NOₓ), which play a major role in smog formation and air pollution. Statement 3 is correct: Indian coal, particularly the variety found in the eastern and central regions, is known for its high ash content (30-50%), which reduces its calorific value and increases pollution levels.Due to its high ash content, Indian thermal power plants generate large quantities of fly ash. Therefore, all three statements are correct.