Table 2. The influence of risk factors on the calculated environmental impact quotient (EIQ) as determined by simulation analysis (N = 100,000) for herbicides applied before crop emergence (PRE) and herbicides applied after crop emergence (POST).

	Relative influence a
Risk factor b	PRE (P = 1)	POST (P = 3)	Interaction with P
Dermal toxicity (DT)	6.0	8.0	1.0
Chronic toxicity (C)	6.6	9.0	1.2
Fish toxicity (F)	1.0	1.0	0.0
Leaching potential (L)	0.3	0.3	0.0
Surface loss potential (R)	1.0	1.0	0.0
Bird toxicity (D)	2.0	3.0	0.5
Soil half-life (S)	2.0	2.0	0.0
Bee toxicity (Z)	1.0	3.0	1.0
Beneficial arthropod toxicity (B)	1.7	5.0	1.6

^aRelative influence is the expected change in EIQ as the risk factor value increases by 1 unit

^bThe EIQ also includes “systemicity” (SY), but this risk factor is set to 1 for all herbicides; it was therefore not included in the simulation.