Consider the following: 1. Carbon dioxide 2. Oxides of Nitrogen 3. Oxides of Sulphur. Which of the above is/are the emission/emissions from coal combustion at thermal power plants?

There is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon? 1. Discharge of nutrients from the estuaries. 2. Run-off from the land during the monsoon. 3. Upwelling in the seas.

Recently, "oilzapper" was in the news. What is it?

Lead, ingested or inhaled, is a health hazard. After the addition of lead to petrol has been banned, what still are the sources of lead poisoning?