Volume 50, Number 1, December 2003:
A Toxicology Primer for Student Inquiry: Biological Smoke Detectors

Text-only version

ISSUE HOME PAGE

ABOUT THIS ISSUE
- about KSN
- about the author
- acknowledgements

IN THIS ISSUE
- disclaimer, objectives
- "biological smoke detectors"
- purpose of invertebrate toxicity testing
- lethal and sublethal effects
- some wormy ideas for toxicity testing
- sublethal chemical effects in lumbriculus
- selecting the chemical(s)
- safety
- exposure methods
- preliminary experiments and concentration range-finding
- final stages of toxicity testing
- typical equipment and supplies
- other organisms, other ideas
- obtaining background information
- references
- glossary of toxicological terms

A Toxicology Primer for Student Inquiry:
Biological Smoke Detectors
by Charles Drewes

“BIOLOGICAL SMOKE DETECTORS”

Recently, I met with several middle school students and their teacher to discuss their proposed student research project in environmental toxicology.  One of these students asked me why anyone would study effects of a toxicant on invertebrate organisms, such as freshwater oligochaete worms.  I tried to explain and justify using the old analogy of a “canary in the coal mine.”  However, based on the group’s quizzical reaction, I realized that the analogy was alien and from a by-gone era (Figure 1). 

Obviously, I needed an updated analogy to emphasize how living organisms are used as “early warning systems,” or sentinels, for detecting harmful substances in the environment and for studying their biological effects.  One familiar and modern warning device is a “smoke detector”... thus the title, “Biological Smoke Detectors.”  When a smoke detector goes off it doesn’t necessarily mean there’s a fire or that anyone will be harmed, but it does indicate a potential problem that requires close and immediate inspection.  The same is true for toxicity tests that signal adverse biological effects on living organisms.

Figure 1.  The canary was once used as sensitive bio-indicator for the presence of poisonous gas in underground mine shafts.  Today, the term “canary in a coal mine” is an antiquated metaphor used in reference to many types of “early warning systems.”