Statement 1 is Incorrect: Carbon dioxide (CO2) is a greenhouse gas primarily responsible for global warming, but it is not one of the eight pollutants considered in the calculation of India's National Air Quality Index (AQI).
Statement 2 is Correct: Carbon monoxide (CO) is one of the eight pollutants monitored under the National AQI, as it is a toxic gas produced by incomplete combustion that affects oxygen transport in the blood.
Statement 3 is Correct: Nitrogen dioxide (NO2) is included in the AQI calculation; it is a major air pollutant emitted from vehicle exhausts and industrial processes that causes respiratory issues.
Statement 4 is Correct: Sulphur dioxide (SO2) is a criteria pollutant for the AQI, primarily released from the burning of fossil fuels in power plants and industrial facilities.
Statement 5 is Incorrect: Methane (CH4) is a potent greenhouse gas and a precursor to ground-level ozone, but it is not directly measured or included as a parameter in the National AQI calculation.
Note: The National Air Quality Index (AQI) in India considers eight pollutants: Particulate Matter (PM10), Particulate Matter (PM2.5), Nitrogen Dioxide (NO2), Sulphur Dioxide (SO2), Carbon Monoxide (CO), Ozone (O3), Ammonia (NH3), and Lead (Pb).