Soil - Environmental Transformations - page 71

plants that can remove carbon from the atmos-
phere (recent estimates show that soil degradation
resulted in 800 million tons less carbon being
fixed from the atmosphere between 1981 and 2003
(Dent et al, 2007: 93)).

first instance, toxic chemicals produced from
various industrial processes routinely make their
way into soil. Heavy metals, such as lead, have
accumulated in soils over many decades largely as
a result of the use of lead in petrol (see Chapter 3
for more details). Toxic chemicals such as mercury
and cyanide (which are by-products of the mining
and manufacturing industries) are transferred to
soils through watercourses and drainage systems
(Dent et al, 2007). Certain soils are now also home
to the hydrocarbons that are the by-products of
the petroleum industry, and to the radioactive
substances that have been released by the nuclear
industry. The accumulation of these harmful
substances significantly reduces the ability of soils
to support the ecosystems of which they are a part.
Soil pollution of this kind also means that many
areas can no longer be used to safely produce food
for human production. This process places greater

4.2.3 Soil pollution and the
disruption of the nitrogen
cycle
Soil degradation is the product of the unsustain-
able removal of water, nutrients and organic
content from soil. There are, however, other
environmental problems that are created by
what is added to soil. Soil pollution can take
two forms: 1) the unintended substances that
are added to soil as a consequence of pollution
events; and 2) the substances that are added to soil
in order to enhance its productive capacity. In the

Box 4.2 Rachel Carson

For many people, the publication in 1962 of Rachel Carson's Silent Spring was a defining moment
in the emergence of the modern environmental movement. Carson was born in Pennsylvania in
1907 and went on to study English and science at Johns Hopkins University in Baltimore. Following
her academic studies, Carson went on to become a biologist with the US Fish and Wildlife Service
(Corcoran, 2001). Her love of English and biology led her to write a series of topics on the sea: Under
the Sea-Wind (1951); The Sea Around Us (1951); and The Edge of the Sea (1955) (Corcaran, 2001:
195). Carson's interest in the impacts of the application of DDT began in 1958 when she wrote an
article exploring the impacts of the insecticide on bird populations (although it appears that she was
concerned about the ecological impacts of the chemical back in 1945) (Corcoran, 2001). This article
was a precursor to an extended period of research by Carson on the impacts of DDT, which ultimately
led to the publication of Silent Spring. One of the most notable features of Silent Spring was its
ability to combine the authority of science with a poetic concern with the natural world. Carson's
work would ultimately lead to much tighter regulations on the use of pesticides throughout the world.
Beyond this, however, Rachel Carson appears to be among the first scientists to recognize the scale
of the environmental changes that humans were capable of achieving. As such, her work is a
harbinger of the debates that we are now having about the Anthropocene.

Key readings

Carson, R. (1962) Silent Spring, Houghton-Mufflin Company, Boston, MA
Corcoran, P. B. (2001) 'Rachel Carson' in Palmer, J.A. (ed.) Fifty Key Thinkers on the Environment, Routledge,
London: 194-200