- Place millions
of Americans potentially at risk.
PROGRESS
IN MEDICAL RESEARCH
All working people
are potentially exposed to toxic substances in their workplace
and certain human cancers may be caused by occupational exposures.
Examples include cancers due to vinyl chloride, asbestos,
benzene, B-napthylamine and arsenic. Other health effects
including neurological disorders, skin problems and sterility
or lowered fertility may also result from toxic chemical exposures.
For example, some workers exposed to the pesticide debromochloropropane
(DCBP) in California became sterile.
How
has animal research helped with occupational diseases?
The use of animals
has helped us to find the causes of many occupational diseases
including silicosis, asbestosis and coal-workers' pneumoconiosis.
Rodents were used to study the effects on the lung of inhaling
airborne particles. Since many occupational lung diseases
are either disabling (e.g. asthma) or cause death (lung cancer),
animal studies such as these have made a major contribution
to human health. Animals are now primarily used to assess
the toxicity or cancer-causing potential of chemicals before
workers are exposed to them. We should not have to wait until
people get sick or die before we can determine that a chemical
is not safe for human exposure.
Is
animal research still needed in occupational health?
Unquestionably
yes. Approximately 1,000 new chemicals are synthesized each
year and modern technology uses chemicals in previously unimagined
ways. By law, we must protect people from the potentially
toxic effects of these chemicals through testing with animals.
What's
ahead in occupational health?
Animal research
in Michigan and elsewhere is defining the health problems
related to chronic, low level exposures to toxic substances,
such as lowered reproductive capacity, behavioral changes
and cancer. This research should enable us to evaluate better
the likely consequences of long-term exposure to a given chemical
in human populations. Research is also underway on human tissue
cultures to provide alternatives to the use of animals in
toxicity testing. This research should be supported further.
However, the likelihood of such systems ever being able to
predict the cancer-causing capacity of a chemical in systems
as complex as humans or animals is slim. For this reason,
continued animal research will be required for many years.
|
