Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.

Various indicators of pesticide environmental risk have been proposed, and one of the most widely known and used is the environmental impact quotient (EIQ). The EIQ has been criticized by others in the past, but it continues to be used regularly in the weed science literature. The EIQ is typically c...

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Main Authors: Andrew R Kniss, Carl W Coburn
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4487257?pdf=render
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author Andrew R Kniss
Carl W Coburn
author_facet Andrew R Kniss
Carl W Coburn
author_sort Andrew R Kniss
collection DOAJ
description Various indicators of pesticide environmental risk have been proposed, and one of the most widely known and used is the environmental impact quotient (EIQ). The EIQ has been criticized by others in the past, but it continues to be used regularly in the weed science literature. The EIQ is typically considered an improvement over simply comparing the amount of herbicides applied by weight. Herbicides are treated differently compared to other pesticide groups when calculating the EIQ, and therefore, it is important to understand how different risk factors affect the EIQ for herbicides. The purpose of this work was to evaluate the suitability of the EIQ as an environmental indicator for herbicides. Simulation analysis was conducted to quantify relative sensitivity of the EIQ to changes in risk factors, and actual herbicide EIQ values were used to quantify the impact of herbicide application rate on the EIQ Field Use Rating. Herbicide use rate was highly correlated with the EIQ Field Use Rating (Spearman's rho >0.96, P-value <0.001) for two herbicide datasets. Two important risk factors for herbicides, leaching and surface runoff potential, are included in the EIQ calculation but explain less than 1% of total variation in the EIQ. Plant surface half-life was the risk factor with the greatest relative influence on herbicide EIQ, explaining 26 to 28% of the total variation in EIQ for actual and simulated EIQ values, respectively. For herbicides, the plant surface half-life risk factor is assigned values without any supporting quantitative data, and can result in EIQ estimates that are contrary to quantitative risk estimates for some herbicides. In its current form, the EIQ is a poor measure of herbicide environmental impact.
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spelling doaj.art-37af5fe7e12e43fc9a28e013e70af7822022-12-21T23:54:01ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01106e013120010.1371/journal.pone.0131200Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.Andrew R KnissCarl W CoburnVarious indicators of pesticide environmental risk have been proposed, and one of the most widely known and used is the environmental impact quotient (EIQ). The EIQ has been criticized by others in the past, but it continues to be used regularly in the weed science literature. The EIQ is typically considered an improvement over simply comparing the amount of herbicides applied by weight. Herbicides are treated differently compared to other pesticide groups when calculating the EIQ, and therefore, it is important to understand how different risk factors affect the EIQ for herbicides. The purpose of this work was to evaluate the suitability of the EIQ as an environmental indicator for herbicides. Simulation analysis was conducted to quantify relative sensitivity of the EIQ to changes in risk factors, and actual herbicide EIQ values were used to quantify the impact of herbicide application rate on the EIQ Field Use Rating. Herbicide use rate was highly correlated with the EIQ Field Use Rating (Spearman's rho >0.96, P-value <0.001) for two herbicide datasets. Two important risk factors for herbicides, leaching and surface runoff potential, are included in the EIQ calculation but explain less than 1% of total variation in the EIQ. Plant surface half-life was the risk factor with the greatest relative influence on herbicide EIQ, explaining 26 to 28% of the total variation in EIQ for actual and simulated EIQ values, respectively. For herbicides, the plant surface half-life risk factor is assigned values without any supporting quantitative data, and can result in EIQ estimates that are contrary to quantitative risk estimates for some herbicides. In its current form, the EIQ is a poor measure of herbicide environmental impact.http://europepmc.org/articles/PMC4487257?pdf=render
spellingShingle Andrew R Kniss
Carl W Coburn
Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.
PLoS ONE
title Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.
title_full Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.
title_fullStr Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.
title_full_unstemmed Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.
title_short Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.
title_sort quantitative evaluation of the environmental impact quotient eiq for comparing herbicides
url http://europepmc.org/articles/PMC4487257?pdf=render
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