Consequences for Human Populations


These changes in urban environments have obvious consequences for their human populations. Increased levels of airborne and waterborne pollutants have adverse effects on human life. Large cities and cities in mountain basins are particularly prone to air quality problems stemming from the burning of fossil fuels for transportation, electrical generation and heat. Urban water supplies have to be monitored carefully for increased levels of toxins. Changes in the flow of water through cities sometimes leaves them vulnerable to flash floods. More subtle effects are sometimes noted. Many people moved to the desert regions of the American Southwest between the 1930s and 1960s for health reasons, to escape respiratory problems in the dry, relatively pollen-free environment. But they brought along decorative plants and trees which added pollens to the air in such quantity that there is now little difference between the pollen counts in cities such as Phoenix and Tucson and cities to the east and north.


This view overlooking Los Angeles shows the vast effects of urbanization. (Courtesy of Ken Foote)


created 3/9/2002; last revised 5/1/2002 - Matt Kuhn & Andreas von der Dunk