holds a special dread in our culture. If Rachel Carson helped publicize
suspected links between rising cancer rates and increasing use of
synthetic pesticides, other forces added momentum to the emerging
cancer paradigm. In June 1969, the National Cancer Institute completed
animal tests prompted by Silent Spring and did find a higher incidence
of liver tumors in mice exposed over a long period to low levels
of DDT. Within a week, President Richard Nixon received a petition
from seventeen congressmen, who asked for a ban on DDT on the grounds
that it caused cancer. In 1971,President Nixon declared an all-out
War on Cancer. Given the temper of the time and new evidence that
pesticides like DDT might cause cancer, environmentalists seeking
to ban DDT began to frame the battle around human health risks rather
than the wildlife and environmental concerns put forward in earlier
phases of the long campaign. In his 1972 decision to restrict most
uses of DDT, U.S. Environmental Protection Agency Administrator
William Ruckelshaus gave equal prominence to possible human cancer
risks and to the adverse impacts on fish and wildlife.
as cancer holds a special place in our fears, it also commands a
special place in federal regulation. It has defined and driven the
EPA's regulatory process for toxic chemicals for more than two decades,
mainly because the agency uses different assumptions for assessing
cancer risk than it does when considering other risks. For noncancer
hazards such as reproductive and developmental damage, the agency
assumes that a chemical may pose no hazard in low concentrations
beneath some threshold level. But when it is a question of cancer,
the EPA turns to a linear model, which assumes that no level is
safe. Even the tiniest dose of a chemical is presumed capable of
The federal appeals court had reinforced such a regulatory bias
by a series of rulings on pesticides in the early 1970s, beginning
with a 1970 case concerning federal tolerance levels for DDT residues
on food. The Environmental Defense Fund, which brought the action,
based its case on the Delaney clause, a 1958 amendment to the Federal
Food, Drug, and Cosmetic Act, which prohibits the use of any food
additive that has been shown to cause cancer in laboratory animals.
In its opinion, the court decided that this law applies to pesticide
residues as well and that the carcinogenicity of these residues
has to be considered in setting tolerance limits. The court also
required the responsible cabinet secretary to explain the basis
for deciding any level of DDT residues to be safe if he proposed
continuing to allow residues in food commodities. The ruling in
effect endorsed the strict attention to carcinogens that the Delaney
clause mandates. By the mid-70s, "cancer-causing" had
become inextricably wedded to the words "toxic chemical"
in the popular culture.
cancer as the ultimate measure of our fears, it was widely assumed
that setting levels based on cancer risk would protect humans as
well as fish and wildlife from all other hazards as well. So over
the past two decades, pesticide manufacturers and federal regulators
looked mainly for cancer and obvious hazards such as lethal toxicity
and gross birth defects in screening chemicals for safety. Cancer
has also dominated the scientific research program exploring possible
human health effects from chemical contaminants in the environment.
This preoccupation with cancer has blinded us to evidence signaling
other dangers. It has thwarted investigation of other risks that
may prove equally important not only to the health of individuals
but also to the well-being of the society.
this book contains a single prescriptive message, it is this: we
must move beyond the cancer paradigm. Until we do, it will be impossible
to grapple with the challenges of hormone disrupting chemicals and
the threat they pose to the human prospect. This is not simply an
argument for broadening our horizons to recognize additional risks.
We need to bring new concepts to our consideration of toxic chemicals.
The assumptions about toxicity and disease that have framed our
thinking for the past three decades are inappropriate and act as
obstacles to understanding a different kind of damage.