Which of the following is/are true?
I. Benzene hexachloride is a non-biodegradable pollutant.
II. Anthropogenic air pollutants are natural in origin.
III. Carbon monoxide is a primary air pollutant.
IV. Sulphur dioxide causes brown air effect during traffic congestion in cities.
Non-degradable pollutants either do not degrade, or may degrade extremely slowly in the natural environment. e.g., DDT, BHC. Anthropogenic pollutants are man-made pollutants such as sewage, pesticides, fertilisers, etc. Primary air pollutants are those which pollute the air directly as soon as they get released from the source. Carbon monoxide is an example. In traffic congested cities, the brown air effect is caused due to oxides of nitrogen.