Comparative evaluation of pesticide risk indices for policy development and assessment in the United Kingdom

The objective of this work was to review the appropriateness of five pestic ide risk indices for use in policy development and assessment in the UK. A common data set of 133 pesticides, constituting 25 insecticides, three moll uscicides, 40 fungicides, 60 herbicides and five plant growth regulators wa s used to enable a comparative evaluation of the risk indices. There was poor correlation between the ranking of the 133 pesticides as giv en by each of the five indices when only toxicological data were used in th e risk calculation. The correlation was improved when data on recommended a pplication rates were incorporated alongside toxicological data in the risk calculations. There was wide variation in the products placed in the top 10 (most hazardo us) and bottom 10 (least hazardous) of the respective rankings when risk wa s based only on toxicological data. All the indices showed a degree of clum ping in the classification of the pesticides, with many pesticides being gr ouped together in one quartile of the indices' potential range. The use of these indices in policy development and assessment is problemati cal. The lack of correlation in the rankings between the indices makes sele ction of any one particular index difficult, and clearly the results of any analysis undertaken will depend on the index selected. Whilst calculation and manipulation of the indices was straightforward, data collection was di fficult for nearly all indices. This is a major constraint to their utilisa tion in policy. (C) 2001 Elsevier Science B.V. All rights reserved.