Table 4.

Adjustments for postnatal exposure to PCBs, PCDD/Fs and PBDEs using a multiple linear regression

		Sum of PCDD/Fs	Sum of PCBs	Sum of PBDEs	Total-TEq
Countrya	β (95 % CI)b	0.61 (0.43–0.87)	1.20 (0.79–1.81)	0.53 (0.33–0.83)	1.13 (0.81–1.57)
	p	0.006	0.38	0.007	0.46
	R2	0.08	<0.01	0.10	<0.01
Duration of breastfeedinga	β (95 % CI)c	1.08 (1.05–1.12)	1.16 (1.12–1.21)	1.01 (0.97–1.05)	1.13 (1.10–1.17)
	p	<0.001	<0.001	0.70	<0.001
	R2	0.27	0.44	0.05	0.48
Age at the operationa	β (95 % CI)d	1.00 (0.99–1.01)	1.00 (0.99–1.01)	1.01 (1.00–1.02)	1.00 (0.99–1.00)
	p	0.73	0.83	0.27	0.27
	R2	<0.01	<0.01	0.02	<0.01

^aAltogether 40 cases and 33 controls. ^bRegression coefficients for the ratio of mean chemical concentrations in Danish versus Finnish subjects, adjusted for duration of breastfeeding and age at the operation. ^cRegression coefficients for the relative increase in adjusted chemical concentrations per month of breastfeeding, adjusted for country of origin and age at operation. ^dRegression coefficients for the relative increase in chemical concentrations per month of age at operation, adjusted for country of origin and duration of breastfeeding