HR: 14:15h
AN: A23C-01 INVITED     [Abstracts]
TI: Air Pollution in the Mexico Megacity
AU: * Ruiz-Suarez, L G
EM: ruizs@servidor.unam.mx
AF: Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico, DF 04510, Mexico
AB: Mexico City is a megacity whose metropolitan area includes the country federal district, 18 municipalities of the State of Mexico. In year 1992, only 16 municipalities of the State of Mexico were part of MCMA. In year 1940 the Mexico City population was 1.78 millions in an area of 118 km², in year 2000 the population was 17.9 millions in an area of 1,500 km². Population has grown a ten fold whereas population density has dropped 20%. Total number of private cars has grown from 2,341,731 in year 1998 to 2,967,893 in year 2004. Nowadays, people and goods travel longer at lower speed to reach school, work and selling points. In addition highly efficient public transport lost a significant share of transport demand from 19.1 in 1986 to 14.3 in 1998. Air pollution is a public concern since early eighties last century; systematic public efforts have been carried out since late eighties. Energy consumption has steadily increased in the MCMA whereas emissions have also decreased. From year 2000 to 2004, the private cars fleet increased 17% whereas CO, NOx and COV emissions decreased between 20-30%. Average concentrations of criteria pollutants have decreased The number of days that the one-hour national standard for bad air quality was exceeded in year 1990 was 160. In year 2005 was 70. Research efforts and public policies on air pollution have been focused on public health. We are now better able to estimate the cost in human lives due to air pollution, or the cost in labor lost due to illness. Little if none at all work has been carried out to look at the effect of air pollution on private and public property or onto the cultural heritage. Few reports have can be found on the impact of air pollution in rural areas, including forest and crops, around the mega city. Mexico City is in the south end of a Valley with mountain ranges higher than 1000 m above the average city altitude. In spite the heavy loss of forested areas to the city, the mountains still retain large forest under strong demographic pressure and under heavy impact of air pollution. Flow patterns induced by complex terrain in the center of Mexico induce strong interaction between the mega city and the rural areas in the Mexico Basin. In and out mesoscale transport to and from the neighboring valleys with cities already larger than one million inhabitants increase the complexity of air pollution processes. Fast urbanization in these valleys suggests even more complicated and full of concerns scenarios. Some recent results on these issues will be shown.
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0478 Pollution: urban, regional and global (0345, 4251)
DE: 0490 Trace gases
DE: 0493 Urban systems
DE: 6349 General or miscellaneous
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly