Environmental Engineering Reference
In-Depth Information
intensive because of the machinery used. In addition, conventionally
grown cotton uses more insecticides than any other single crop: world-
wide, cotton growers use more than 10 percent of the world's pesticides
and nearly 25 percent of the world's insecticides. Cotton is also respon-
sible for 25 percent of all chemical pesticides used on American crops.
Most of the cotton grocery bags are woven outside the United States
where labor is less costly, but that increases the use of fossil fuels to get
them from the foreign factories to our shores.
In summary, there is no free lunch. Everything that is manufactured
has environmental costs, and when we attempt a life cycle analysis to
determine relative greenness, the answer is often not clear. The opinions
of the public are commonly infl uenced more by the relative strengths of
advertising campaigns than by an objective evaluation of the facts.
Litter: Do We Care?
Littering has decreased by almost two-thirds in America since 1950 but
is still widespread, as everyone knows. Tobacco products are the biggest
problem, accounting for 38 percent of litter, with paper products at 22
percent, plastic at 19 percent, metal at 6 percent, and glass at 4 percent.
The biggest growth category has been plastic because of the increase in
plastic packaging at the expense of glass, paper, and metal.
Who Wants My Garbage?
Good waste management attempts fi rst to reduce the amount of waste
produced, then to recycle whatever is recyclable, to compost what is
compostable, and fi nally to dispose of the remaining waste in an envi-
ronmentally responsible manner. The fi nal waste goes to either a waste
processing facility, typically one that turns it into energy, or, more often,
to a landfi ll. The environmental impacts are considerably different.
Landfi lls
There are three ways to dispose of trash: it can be buried (landfi lls),
burned (incinerators), or partially recovered and recycled.
Fifty-four percent of household garbage goes to landfi lls, a percentage
that has not changed since 2000, and the number of landfi lls has remained
constant at 1,754 since 2002, although the size of some has increased.
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At the national level, landfi ll capacity appears to be adequate, although
it is limited in some areas.
