NEET BIOLOGY

Detailed explanation-1: -Located in the crater of an extinct volcano, Mexico City is about 2, 240 metres above sea level. The lower atmospheric oxygen levels at this altitude cause incomplete fuel combustion in engines and higher emissions of carbon monoxide and other compounds. Intense sunlight turns these into higher than normal smog levels.

Detailed explanation-2: -But vehicles do generate 82% of Mexico City’s emissions of harmful NO X, the other precursor of ozone, and are responsible for around 45% of total CO 2, 99% of CO, and 23% of large particulate matter emissions citywide.

Detailed explanation-3: -Mexico City sits in a high mountain valley, where the surrounding mountains can trap pollutants and prevent them from dispersing. The city is 7, 350 feet (2, 240 meters) above sea level.