RISKS OF GENETIC ENGINEERING
Many previous technologies have proved to have
adverse effects unexpected by their developers. DDT, for example,
turned out to accumulate in fish and thin the shells of fish-eating
birds like eagles and ospreys. And chlorofluorocarbons turned
out to float into the upper atmosphere and destroy ozone,
a chemical that shields the earth from dangerous radiation.
What harmful effects might turn out to be associated with
the use or release of genetically engineered organisms?
This is not an easy question. Being able to
answer it depends on understanding complex biological and
ecological systems. So far, scientists know of no generic
harms associated with genetically engineered organisms. For
example, it is not true that all genetically engineered foods
are toxic or that all released engineered organisms are likely
to proliferate in the environment.
But specific engineered organisms may be harmful
by virtue of the novel gene combinations they possess. This
means that the risks of genetically engineered organisms must
be assessed case by case and that these risks can differ greatly
from one gene-organism combination to another.
So far, scientists have identified a number
of ways in which genetically engineered organisms could potentially
adversely impact both human health and the environment. Once
the potential harms are identified, the question becomes how
likely are they to occur. The answer to this question falls
into the arena of risk assessment.
In addition to posing risks of harm that
we can envision and attempt to assess, genetic engineering
may also pose risks that we simply do not know enough to identify.
The recognition of this possibility does not by itself justify
stopping the technology, but does put a substantial burden
on those who wish to go forward to demonstrate benefits.