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

TYPICAL EQUIPMENT AND SUPPLIES

Here is a list of materials and equipment that may be used for toxicity testing in freshwater or terrestrial oligochaetes.  Check with instructor/mentor for approval or modification of the list.

• Calibrated pipetter (e.g., Pipetman) for measuring milliliter or microliter quantities of chemicals that are fluids
• Balance for measuring milligram or sub-milligram quantities of chemicals that are solids
• Uncontaminated glassware for making serial dilutions and storing chemical stock solutions
• Large supply of identical covered dishes or jars (such as clean, dry baby food jars with covers; jars should thoroughly cleaned but must not contain any soap residues since these will kill many aquatic invertebrates); containers must not be prone to spills and should be easy to handle; one organism recommended per container (such as, 6 organisms/group x 5 groups = 30 containers)
• Filter paper discs that easily fit into the bottom of the exposure dish or jar (some trimming may be necessary)
• Sturdy box or tray for storage and transfer of treatment dishes or jars
• Counter space covered with clean, absorbent, disposable material, such as paper towel
• Safe storage location for all stock solutions, solvents, and all experimental containers (fume hood, if possible)
• Disposable vinyl (or latex) gloves
• Protective eyewear and lab coat (as advised and needed)
• Spring water (Note: Freshwater organisms survive and perform best in spring water.  Examples of brand names of “worm-friendly” spring water are Evian, Poland Spring, Naya, and many others).  Aqueous stock solutions of chemicals and serial dilutions of stock solutions all should be made with this water and stored in separate, clearly labeled containers.  Chlorinated water, directly from the tap, is highly toxic to freshwater invertebrates.  However, tap water that has been aged in a open container for at least a week is often just as safe to worms as spring water.)
• Ethanol, or other solvent (needed only if chemical is not water-soluble)
• Capped or covered containers for storage of stock solutions (approximately 100-500 ml volume)
• Scientific calculator
• Paper towels
• Adhesive labels or colored labeling tape for labeling test dishes and containers with stock solutions
• Permanent marking pen
• Experimental organisms with appropriate maintenance or culture containers (large dishes, aquaria. etc.)
• Supplies for handling, feeding, and care of organisms (such as air pump for aquatic species)
• Thermometer (to document temperature of all experiments)
• Test chemical, along with MODS sheets and/or International Chemical Safety Card with pertinent technical information about density, solubility, formula weight, handling instructions, hazards, safety, storage, etc.
• Bound notebook and pen for record keeping
• Dissecting or compound microscope with light source
• Recording/monitoring devices (e.g., camera, camcorder, video camera, etc.), if desired for documentation of behavioral effects (optional)
• Blackworms (Lumbriculus variegatus); two commercial sources are:
  1. KORDON (A Division of NOVALEK, Inc.), 2242 Davis Ct., Hayward, CA 94545-1114 www.novalek.com/korgde1.htm
  2. AQUATIC RESEARCH ORGANISMS, P.O. Box 1271,  One Lafayette Road, Hampton, NH  03842 [Sells many invertebrate species for toxicity testing]  www.holidayjunction.com/aro/