Table 2.

Estrogen receptor-mediated luciferase expression (measured as light emission) observed in MCF-7-ERE cells exposed during 24 hours to single compounds or mixtures of selected POPs. All mixtures contained the same weight proportion of the constituents to achieve the concentration of 80 ng/mL, 400 ng/mL, or 2000 ng/mL medium (n = 3).

	Relative response (%)a			EEQ (ng/mL)b
	80 ng/mL	400 ng/mL	2000 ng/mL	80 ng/mL	400 ng/mL	2000 ng/mL
PCB 138	<LOQ	<LOQ	<LOQ	n/a	n/a	n/a
PCB 153	<LOD	<LOD	<LOQ	n/a	n/a	n/a
PCB 180	<LOD	<LOD	<LOD	n/a	n/a	n/a
Mixture of PCB congeners (1)	<LOD	<LOD	<LOQ	n/a	n/a	n/a
o,p′-DDT	28 ± 0	67 ± 3	72 ± 7	2.1 ± 0.0 × 10−3	7.6 ± 0.8 × 10−3	9.4 ± 2.4 × 10−3
o,p′-DDD	<LOD	29 ± 3	66 ± 3	n/a	2.1 ± 0.2 × 10−3	7.3 ± 0.6 × 10−3
p,p′-DDT	<LOD	<LOQ	36 ± 2	n/a	n/a	2.8 ± 0.2 × 10−3
p,p′-DDD	<LOD	<LOQ	32 ± 2	n/a	n/a	2.4 ± 0.2 × 10−3
p,p′-DDE	<LOD	<LOQ	21 ± 1	n/a	n/a	1.5 ± 0.0 × 10−3
Mixture of DDT and its metabolites (2)	<LOQ	26 ± 1	49 ± 4	n/a	1.9 ± 0.1 × 10−3	4.3 ± 0.5 × 10−3
β-HCH	<LOQ	35 ± 2	64 ± 4	n/a	2.7 ± 0.1 × 10−3	6.8 ± 1.0 × 10−3
δ-HCH	<LOQ	<LOQ	20 ± 3	n/a	n/a	1.4 ± 0.2 × 10−3
γ-HCH	<LOD	<LOQ	<LOQ	n/a	n/a	n/a
α-HCH	<LOD	<LOQ	<LOQ	n/a	n/a	n/a
HCB	<LOD	<LOD	<LOD	n/a	n/a	n/a
Mixture of HCH isomers and HCB (3)	<LOQ	<LOQ	23 ± 1	n/a	n/a	1.7 ± 0.1 × 10−3
Mixture (1) + (2)	<LOQ	32 ± 1	52 ± 2	n/a	2.4 ± 0.1 × 10−3	4.7 ± 0.3 × 10−3
Mixture (1) + (3)	<LOQ	<LOQ	28 ± 2	n/a	n/a	2.1 ± 0.2 × 10−3
Mixture (2) + (3)	<LOQ	20 ± 7	54 ± 2	n/a	1.5 ± 0.5 × 10−3	5.0 ± 0.3 × 10−3
Mixture (1) + (2) + (3)	<LOQ	27 ± 1	54 ± 2	n/a	2.0 ± 0.1 × 10−3	5.0 ± 0.3 × 10−3

^aThe maximal response observed for E2 was arbitrarily set to 100% and the responses observed for the chemicals and mixtures are expressed in percentage of the maximal response (relative response).

^bEstradiol equivalents were determined by linear extrapolation from calibration curves obtained after exposure to E2 and are expressed in ng/mL culture medium.

n/a: not applicable.