The study of the relationship between environmental pollution and human
health is in its infancy. The number of substances and mixtures that
have been identified in uncontrolled hazardous waste sites or that have
been in- advertently released into the environment is large and data on
how thes substances are modified as they interact with one another as
they migrate through soil, air, and water are limited. There are also
limits on our un- derstanding of how these substances may be ingested,
inhaled, or absorbed by people. The complexity of possible interactions
between biological, chemical, and physical components in a given
environment makes it virtually impossible to evaluate the potential for
adverse biological effects ade- quately in the laboratory. Other, more
comprehensive methods which provide realistic and interpretable results
must be used. Many scientists believe that humans represent the ultimate
sentinel species of a toxic exposure re- sUlting from environmental
pollution, however such exposures may also se- verely impact
environmental health. There exists a wide variety of organ- isms in the
natural environment that could be used to provide an early warning for
potential human health effects as well as to indicate adverse ecological
effects. The issue of effective utilization of sentinel species for
environment- al monitoring is a rapidly developing area of research
which has grown in importance during the last decade.