Q. Consider the following common sources of indoor air pollution in Indian urban settings:

1. Use of incense sticks and mosquito coils
2. Poor ventilation and overcrowded spaces
3. Emissions from furniture, paints, and cleaning chemicals
4. Burning of agricultural waste outside the building

Which of the above statements is/are correct?
Answer: 1, 2 and 3 only
Notes: Burning of agricultural waste, given as the fourth statement in the options, is primarily an outdoor source of air pollution. The sources of indoor air pollution primarily stem from practices and materials inside the building such as use of incense sticks and mosquito coils, poor ventilation and overcrowded spaces, and emissions from furniture, paints, and cleaning chemicals, which are given in the first to third statements.