Predicting the aquatic toxicity of commercial pesticide mixtures

Environmental Sciences Europe

Table 4 Frequency of underestimating product toxicity based on the data set "most sensitive endpoints"

	Percentage (%) of MDR
	> 2	> 5	> 10	> 100
Algal growth inhibition
Herbicidal products (58)	12.1	6.9	3.4	1.7
Fungicidal products (45)	20.0	11.1	4.4	0.0
Water plant growth inhibition
Herbicidal products (35)	8.6	5.7	2.9	0.0
Aquatic invertebrate acute toxicity
Herbicidal products (44)	27.3	22.7	18.2	9.1
Fungicidal products (52)	9.6	0.0	0.0	0.0
Fish acute toxicity
Herbicidal products (61)	23.0	19.7	18.0	6.6
Fungicidal products (51)	11.8	2.0	0.0	0.0
Aquatic invertebrate chronic toxicity
Herbicidal products (26)	42.3	23.1	19.2	3.8
Fungicidal products (12)	33.3	33.3	33.3	16.7
Fish chronic toxicity
Herbicidal products (20)	20.0	10.0	10.0	5.0
Fungicidal products (9)	11.1	0.0	0.0	0.0

Given is the percentage of model deviation ratios (MDR), including censored and non-censored data, that were determined as being greater than the value of 2, 5, 10, or 100, respectively, for each of the six different endpoints using the data set compiling the lowest toxicity measures for the individual a.s. within each endpoint. Percentage MDR is related to the number of herbicidal and fungicidal combination products (indicated in parentheses) for which data for the product and all active substances were available for the given endpoint.