Environmental Pollution

To solve this question, we need to match pollutants in List I with their associated diseases or symptoms in List II. Let us analyze each pairing:

1. A. Sulphate (> 500 ppm) is associated with a laxative effect. High concentrations of sulphate in water can cause diarrhea and dehydration, particularly affecting sensitive individuals.
2. B. Nitrate (> 50 ppm) is linked to methemoglobinemia. This condition, often known as "blue baby syndrome," occurs when nitrate in water is converted to nitrite in the body, interfering with the capacity of blood to carry oxygen.
3. C. Lead (> 50 ppb) can cause kidney damage. Lead exposure, even at low levels, can harm the kidneys and affect other physiological processes as well.
4. D. Fluoride (> 2 ppm) leads to brown mottling of teeth, known as dental fluorosis. Excessive fluoride exposure results in discoloration and damage to dental enamel.

Based on these explanations, the correct matchings are:

• A-III: Sulphate - Laxative effect
• B-I: Nitrate - Methemoglobinemia
• C-IV: Lead - Kidney damage
• D-II: Fluoride - Brown mottling of teeth

The correct option is therefore

A-III, B-I, C-IV, D-II

.

Manufacturing of cement, steel manufacturing, and electricity generation in thermal power plants are major contributors to greenhouse gas emissions, primarily CO₂, which is a significant driver of global warming.
Cement production releases CO₂ through the calcination of limestone.
Steel manufacturing uses coal, a carbon-intensive fuel, releasing CO₂.
Thermal power plants also burn fossil fuels to generate electricity, leading to substantial CO₂ emissions.
While urea production does have an environmental footprint, its contribution to global warming is much less than the other three activities listed. The primary greenhouse gas emissions associated with urea production are nitrous oxide (N₂O) from fertilizer application and CO₂ from energy use in the production process. However, these emissions are considerably lower compared to those from cement, steel, and electricity generation.