Environmental Engineering Reference
In-Depth Information
iously on steep hillsides subject to landslides. In these
illegal settlements, people take over unoccupied land
and build shacks from corrugated metal, plastic
sheets, scrap wood, packing crates, and other scav-
enged building materials. Still others live or sleep on
the streets, having nowhere else to go.
Squatters living near the edge of survival in these
areas usually lack clean water supplies, sewers, elec-
tricity, and roads, and they often are subject to severe
air and water pollution and hazardous wastes from
nearby factories. Their locations may also be especially
prone to landslides, flooding, earthquakes, or volcanic
eruptions.
Most cities cannot afford to provide squatter set-
tlements and shantytowns with basic services and pro-
tections, and their officials fear that improving services
will attract even more of the rural poor. In fact, many
city governments regularly bulldoze squatter shacks
and send police to drive the illegal settlers out. The
people then move back in or develop another shanty-
town somewhere else.
How Can Reducing Crime
Help the Environment?
Most people do not realize that
reducing crime can also help im-
prove environmental quality. For
example, events such as robbery,
assault, and shootings can have
several harmful environmental effects.
Crime can drive people out of cities, which
are our most energy-efficient living arrangements.
Every brick in an abandoned urban building repre-
sents an energy waste equivalent to burning a 100-
watt light bulb for 12 hours. Each new suburb
means replacing farmland or reservoirs of natural
biodiversity with dispersed, energy- and resource-
wasting roads, houses, and shopping centers.
Crime can also make people less willing to
walk, bicycle, and use energy-efficient public tran-
sit systems. It forces many people to use more en-
ergy to deter burglars. For example, trees and
bushes planted near a house help save energy by
reducing solar heat gain in the summer and pro-
viding windbreaks in the winter. To thwart break-
ins, many homeowners clear away those trees and
bushes. Many homeowners also use more energy
by leaving lights, TVs, and radios on to deter
burglars.
Finally, the threat of crime causes overpackag-
ing of many items to deter shoplifting or poisoning
of food or drug items.
CONNECTIONS
x
H
OW
W
OULD
Y
OU
V
OTE
?
Should squatters around cities
of developing countries be given title to land they do not
own? Cast your vote online at http://biology.brookscole
.com/miller11.
Despite joblessness, squalor, overcrowding, and
environmental and health hazards, most of these poor
urban residents are better off than their rural counter-
parts. Thanks to the greater availability of family plan-
ning programs, they tend to have fewer children and
better access to schools. Many squatter settlements
provide a sense of community and a vital safety net of
neighbors, friends, and relatives for the poor.
Mexico City is an example of an urban area in cri-
sis. About 18.3 million people—roughly one of every
six Mexicans—live there (Figure 7-13). It is the world's
second most populous city, and each year at least
200,000 new residents arrive.
Mexico City suffers from severe air pollution, close
to 50% unemployment, deafening noise, overcrowding,
traffic congestion, inadequate public transportation,
and a soaring crime rate. More than one-third of its resi-
dents live in slums called
barrios
or in squatter settle-
ments that lack running water and electricity.
At least 3 million people have no sewer facilities.
As a consequence, huge amounts of human waste are
deposited in gutters, vacant lots, and open sewers
every day, attracting armies of rats and swarms
of flies. When the winds pick up dried excrement, a
fecal snow
blankets parts of the city. Open garbage
dumps also contribute dust and bacteria to the atmo-
sphere. This bacteria-laden fallout leads to widespread
salmonella and hepatitis infections, especially among
children.
Critical Thinking
Can you think of any environmental benefits of
certain types of crimes?
Mexico City has one of the world's worst photo-
chemical smog problems because of a combination of
too many cars and polluting industries, a sunny cli-
mate, and topographical bad luck. The city sits in a
high-elevation bowl-shaped valley surrounded on
three sides by mountains—conditions that trap air pol-
lutants at ground level. Breathing its air is said to be
roughly equivalent to smoking three packs of ciga-
rettes per day.
The city's air and water pollution cause an
estimated 100,000 premature deaths per year. Writer
Carlos Fuentes has nicknamed this megacity “Make-
sicko City.”
Some progress has been made. The percentage of
days each year in which air pollution standards are vi-
olated has fallen from 50% to 20%. At the same time,
the city has an inadequate mass transportation system
and retains weak, poorly enforced air pollution stan-
dards for industries and motor vehicles.
