Environmental Impact Quotient
Introduction :
J. Kovach, C. Petzoldt, J. Degni, and J. Tette developed the EIQ model. EIQ calculates a pesticide’s risk to farm workers, consumers, and terrestrial organisms based on a ranking methodology. In this methodology, toxicity information and chemical parameter information are ranked. Then, these ranks are manipulated in equations to arrive at a final EIQ score.
Reference:
- Kovach, J., Petzoldt, C., Degni, J., Tette, J. 1992. A method to measure the environmental impact of pesticides. New York’s Food and Life Sciences Bulletin 139, 1-8.
Equations :
- The final EIQ equation is :
EIQ = (C(DT*5)+(DT*P))+((C*(S+P)2*SY)+(L))
+((F*R)+(D*(S+P)/2*3)+(Z*P*3)+(B*P*5)))/3
The final EIQ score can then be manipulated with the application rate of the pesticide’s active ingredient (in lbs/acre) to arrive at a field use score. - EIP Field Use Rating = EIQ Score * Application Rate
The EIQ model emphasizes a ranking methodology. This ranking scheme has ten different sections detailed below.
List of Symbols :
| Symbol | Description & Units |
| application rate | amount of pesticide a.i. applied (lbs/acre) |
| B | ranked beneficial arthropod toxicity |
| C | chronic toxicity classification |
| D | ranked LC50 mallard value |
| DT | ranked dermal rat LD50 value |
| F | ranked LC50 fish value |
| L | ranked leaching potential of the pesticide a.i. |
| P | ranked plant surface half-life value |
| R | ranked runoff potential of the pesticide a.i. |
| S | ranked soil half-life value |
| SY | systemic pesticide classification |
| Z | ranked LD50 bee value |
Analysis :
The various numbers used in the EIQ equation are weighting factors used by the authors to place more emphasis on certain pesticide characteristics. These weighting factors may reflect the original design of EIQ to only consider common fruit and vegetable pesticides. Users of this model should also pay particular attention to the ranking methodology. For example, with this methodology the user will often have to conduct further research to distinguish a pesticide that is has “medium runoff potential” from a pesticide that has a “large runoff potential.”