The bar graph illustrates the average minimum and maximum amounts of polluted gas per day in 4 cities in 2000. Overall, Mexico City was the most contaminated in terms of pollutant emissions compared to the others.
In Los Angeles, the quantity of SO2 took the lowest position with a minimum and maximum of 2 and 10 micrograms per m3 respectively. Meanwhile, the levels of N2O were much higher as the maximal number reached up to 104 micrograms. In contrast, Mexico was the most polluted among the 4 cities, with the smallest emission statistics of SO2 and NO2 at 80 and 113 respectively, while the maximal counterparts were around 200.
During the same period, Beijing witnessed the lowest data of SO2 and NO2 with 25 and 14 micrograms per m3, whereas the quantities were four times higher on the most polluted day. In Calcutta, the figure for SO2 emission was approximately more than 50 micrograms, similar to the maximum of NO2.