Appendix A Tables List
Appendix A Figures List
WARNING NOTES
- The data in the tables are designed to stress how small small really is. By minimizing magnitude, the comparisons tend to minimize risk.
- When the data in the tables are used by those with an obvious interest in minimizing risk, they often lack credibility. They are also likely to provoke the same sort of backlash provoked by self-serving risk comparisons.
- The data often lack relevance and meaning unless coupled with data on the toxic potency of a particular chemical.
- Efforts to minimize small quantities through the comparisons given in the tables may backfire by making the quantity easier to visualize. While an image such as “a drop of vermouth in 500 barrels of gin” may be intended to convey smallness, for some in the audience it serves as an easily visualized and memorable metaphor.
Table A.1
Concentration Comparisons
Organized by Unit Categories
| Unit | 1 part per million | 1 part per billion | 1 part per trillion |
|---|---|---|---|
| Length | 1 in./16 mi. | 1 in./16,000 mi. | 1 in./16,000,000 mi. (a 6-in. leap on a journey to the sun) |
| Time | 1 min./2 years | 1 sec./32 years | 1 sec./320 centuries (or 0.06 sec. since the birth of Jesus Christ) |
| Money | 1 cent/$10,000 | 1 cent/$10,000,000 | 1 cent /$10,000,000,000 |
| Weight | 1 oz./31 tons | 1 pinch salt/10 tons of potato chips | 1 pinch salt/10,000 tons of potato chips |
| Volume | 1 drop vermouth/ 80 “fifths” of gin | 1 drop vermouth/ 500 barrels of gin | 1 drop of vermouth in a pool of gin covering the area of a football field 43 ft. deep |
| Area | 1 square ft./ 23 acres | 1 square in./ 160-acre farm | 1 square ft./the state of Indiana; or 1 large grain of sand on the surface of Daytona Beach |
| Action | 1 lob/1,200 tennis matches | 1 lob/1,200,000 tennis matches | 1 lob/1,200,000,000 tennis matches |
| Quality | 1 bad apple/ 2,000 barrels | 1 bad apple/ 2,000,000 barrels | 1 bad apple/ 2,000,000,000 barrels |
Source: Adapted from Warren B. Crumett, Dow Chemical Company (as reproduced in Rowe, W.D. et al., 1984, Evaluation Methods for Environmental Standards. CRC Press Inc., Boca Raton, Florida.
Warning!
Use of data in this table for risk comparison purposes can damage your credibility (see text).Table A.2
Miscellaneous Concentration Comparisons
Parts per million:
|
Parts per billion:
|
Parts per trillion:
|
Parts per quadrillion:
|
Source: Adapted from data supplied by Jim Callaghan, Hill and Knowlton, Inc., as reproduced in P. Sandman, D. Sachsman, and M. Greenberg, 1987, Risk Communication for Environmental News Sources. Industry/University Cooperative Center for Research in Hazardous and Toxic Substances: New Brunswick, New Jersey.
Warning!
Use of data in this table for risk comparison purposes can damage your credibility (see text).Figure A.1
Air Emissions From Chemical Production
Tons per Year Projected through 1988
for the
Dow Chemical Company, Midland Division
(Image not available)
Source: Adapted from Midland Daily News, June 5, 1987.
Copyright © 1988 by Chemical Manufacturers Association
Abbreviated Table of Contents
Table of Contents and Introduction
I . Effectively Communicating Risk Information
II. Guidelines for Presenting and Explaining Risk-Related Numbers and Statistics
III. Guidelines for Providing and Explaining Risk Comparisons
IV. Concrete Examples of Risk Comparisons
V. Anticipating Objections to Explanations of Chemical Risks
Appendix A: Concentration and Quantity Comparisons
Appendix B: Risk Comparison Tables And Figures
