a UN conference last month, widespread consensus emerged on eliminating
from commerce 12 of the most toxic chemicals on earth, which belong
to a class known as persistent organic pollutants. The consensus
around these chemicals, however, foretells controversy in the
future, and carries us pell- mell toward international disagreement,
and potential trade wars, over other manmade substances.
confrontation between free trade and environmental health, triggered
by technological innovations, is already visible in trans- Atlantic
disputes. Europeans have made clear that they do not want genetically
engineered foods and hormone-treated beef forced on them. U.S.
companies and trade negotiators, meanwhile, protest that the scientific
research on such products remains ambiguous.
to grips with persistent organic pollutants will raise the stakes
for everyone. These substances, known to harm wildlife and humans,
remain chemically active for several decades after they have been
applied. The decision to reduce or eliminate 12 of them is relatively
uncontroversial, so long as important public health exceptions
allow DDT to be used for malaria control until better alternatives
real crunch will come in deciding what criteria to apply to chemicals
that might be banned in the future. Endocrine-disrupting chemicals,
a group that includes a number of widely used pesticides, basic
plastics and plastics additives, are likely to come under international
scrutiny next. Emerging science shows that these compounds interfere
with hormonal action, especially in the developing fetus. They
can wreak havoc with reproductive organs, neurological development
and disease resistance.
U.S. National Academy of Sciences recently released a groundbreaking
report confirming that concerns about these chemicals were plausible
and significant. It noted four reasons to be suspicious of endocrine-disrupting
chemicals. First, laboratory experiments show that they can interfere
with hormones at extraordinarily low concentrations. Second, low
and intermediate concentrations may have especially serious consequences
for fetuses during certain developmental ''windows.'' Third, the
effect of endocring-disrupting chemicals in mixtures cannot be
predicted by studies of one compound alone, although humans experience
these chemicals in so many different combinations that a thorough
toxicological assessment of all likely mixtures is literally impossible.
Finally, the effects of exposure on a fetus may not be apparent
until adulthood, long after knowledge of exposure has disappeared.
academy accurately noted that studies of many potential effects
of these chemicals on humans - such as breast cancer, endometriosis
sperm count declines, lowered immune resistance and learning disabilities
- still need to be done and may take decades to complete. It concluded
that the absence of scientific certainty is not a result of the
chemicals' safety, but of ignorance.
the products that could be affected are major money-makers for
the chemical and pesticide industries. Most notable is bisphenol
A, a building block of polycarbonate plastic but also a mimic
of the hormone estrogen. Polycarbonate leaches bisphenol A into
food from can linings, and into children's saliva when it has
been used as a dental coating to prevent tooth decay. Although
the research on the chemical's health risks is ambiguous, it may
be sufficiently alarming to cause Europe to act.
eventual verdict on many endocrine-disrupting chemicals is virtually
guaranteed: plausibly but not certainly guilty. Yet this is exactly
the kind of circumstance in which Europe has proven willing to
take preventative measures, while the United States, pushed hard
by companies producing these toxic chemicals, has not. The battle
forming over persistent organic pollutants is fundamentally one
of ideas. On the one hand, there is an emerging global consensus
that precautionary action is essential to a healthy, sustainable
planet. On the other, industrial interests are demanding a ''smoking
gun,'' of the type previously required by tobacco manufacturers,
before they are willing to change.
good news is that UN members will likely sign a treaty next year
on eliminating persistent organic pollutants. The unanswered question
is whether this will be a move toward wider acceptance of a higher
public health doctrine. Will we invoke the precautionary principle
as a guide for evaluating potential risks from new technology,
or will commercial interests force society to wait for an impossible
level of proof before acting to protect public health and safety?
Myers is director of the W. Alton
Jones Foundation, a private philanthropy supporting efforts
to protect the global environment and prevent nuclear war.
Lerner is president of Commonweal,
a health and environmental research institute in the San Francisco