In which year was the Air (Prevention and Control of Pollution) Act amended to include noise as air pollution?

According to the $CPCB$,particulate size (in micrometers) that is most harmful to human health is:

Which of the following pollutants can be removed by a scrubber?

Steps taken by the Government of India to control air pollution include:

The Air (Prevention and Control of Pollution) Act came into force in $........$,but was amended in $........$ to include noise as an air pollutant.

What percentage of particulate matter released from thermal power plants is removed by an electrostatic precipitator (in $\%$)?