Results of extended plant tests using more realistic exposure scenarios for improving environmental risk assessment of veterinary pharmaceuticals

Environmental Sciences Europe

Table 9 Effect concentrations (EC₁₀, EC₅₀ with 95 % confidence interval) and NOEC, (mg/kg soil dry mass) for biomass production of B. napus and P. vulgaris of florfenicol spiked via differently treated manure

Manure	Species/endpoint	Standard test (no manure)	Fresh spiked	1/2 max incubation time	Max. incubation time
	B. napus
Cattle	NOEC	<0.06	<0.2	5.60	16.7
	EC₁₀	0.05	0.07	12.1	27.0
	EC₁₀	(0.01–0.09)	(n.d.)	(n.d.)	(n.d.)
	F		1.4	242	540
	EC₅₀	0.25	0.2	20.8	68.0
	EC₅₀	(0.16–0.38)	(n.d.)	(n.d.)	(n.d.)
	F		0.8	83	272
Valid pig		Yes	Yes	Yes	Yes
	NOEC	<0.06	<0.2	16.7	≥16.7
	EC₁₀	0.05	0.08	14.1*	14.3
	EC₁₀	(0.01–0.09)	(0.07–0.09)	(14.0–14.2)	(n.d.)
	F		1.6	282	286
	EC₅₀	0.25	0.21	22.5*	27.8
	EC₅₀	(0.16–0.38)	(0.21–0.22)	(22.3–22.7)	(n.d.)
	Factor		0.84	90	111
Valid		Yes	No (67 % emerged, 60 % survived)	Yes	No (80 % emerged)
	P. vulgaris
Cattle	NOEC	0.56	<0.2	5.60	5.60
	EC₁₀	0.76	0.08	11.8*	8.14*
	EC₁₀	(0.36–1.12)	(0.03–0.16)	(9.14–14.2)	(5.86–10.3)
	F		0.1	16	11
	EC₅₀	2.59	1.18	28.7*	69.7*
	EC₅₀	(2.02–3.36)	(0.81–1.67)	(25.6–32.3)	(58.3–88.4)
	F		0.5	11	27
Valid pig		Yes	Yes	Yes	Yes
	NOEC	0.56	<0.2	16.7	16.7
	EC₁₀	0.76	0.07	11.8	28.2*
	EC₁₀	(0.36–1.12)	(0.00–0.27)	(n.d.)	(24.2–32.2)
	F		0.1	16	37
	EC₅₀	2.59	1.0	27.0	41.2*
	EC₅₀	(2.02–3.36)	(0.26–2.77)	(n.d.)	(39.1–42.6)
	F		0.4	10	16
Valid		Yes	No (80 % emerged)	Yes	Yes

Concentration range (both species): 0.06–5.0 mg/kg soil (standard tests), 0.2–16.7 mg/kg soil (fresh spiked), 0.62–50.0 mg/kg soil (other tests). Results evaluated as % inhibition compared to the standard control (in standard tests) or the manure control (in extended tests)
F factor of difference, ECx (manure spiked test)/ECx (standard test)
* Significantly greater than value from standard test (based on overlapping 95 % confidence intervals)