Social Science (087) — AI-generated practice question

Every litre of industrial wastewater pollutes eight times the quantity of freshwater, making natural dilution insufficient and unreliable.

Industrial effluents contain harmful substances — dyes, acids, heavy metals like lead and mercury, pesticides, and synthetic chemicals — which contaminate rivers and lakes, making water unfit for use.

Treating effluents before discharge (through primary/mechanical, secondary/biological, and tertiary processes) removes these pollutants at the source. Without treatment, contaminated rainwater also percolates into soil, further polluting groundwater reserves, compounding the threat to freshwater availability.

Source: Industrial Pollution and Environmental Degradation; Control of Environmental Degradation — Chapter 6

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• Key stat to remember: 1 litre waste = 8 litres freshwater polluted — examiners expect this figure.
• Name the types of pollutants (heavy metals, acids, dyes) — shows you've read the text.
• Mention all three stages of treatment (primary, secondary, tertiary) — likely worth 1 mark on its own.
• Note the groundwater angle (percolation) — it shows cause-effect thinking that earns full marks.
• Don't write vague statements like "it is harmful" — be specific and factual.