Correlation between T.S.P., F.S.P. and visibility in a high altitude city (Mexico City)

the metropolitan area of Mexico City is located in a high altitude basin (2 240 m above sea level) at a latitude of 19 degrees 26'13" North. It has a population of 15 million inhabitants, and the motor vehicles cruising in the city amount to 1.5 million and around 21% of the total industrial activity of the country is sited in the metropolitan area. All this activity has created an acute air pollution problem in the area which, as a direct result, has resulted in decreased visibility and possible health effects.