Levels of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in human milk from different regions of France.

We report on the pilot study carried out before the start of the Elfe project (French longitudinal study from childhood). A total of 44 samples of mature human milk were collected at home 8 weeks after delivery. A total of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like (DL) polychlorinated biphenyls (PCBs), and 6 non dioxin-like (NDL)-PCBs were measured. For total TEQ (PCDD/Fs and DL-PCBs), the geometric mean concentration was 17.81 pg TEQ(WHO05)/g lipids. Relative PCDD, PCDF, and DL-PCB contributions to the arithmetic mean TEQ(WHO05) were 38%, 18%, and 44%, respectively. The use of TEF(WHO05) instead of TEF(WHO98) resulted in a 27% reduction of the total TEQ value. Although PCDD levels did not significantly change (less than 0.5% increase), PCDF and DL-PCB levels both decreased by 35% and 38%, respectively. Levels have been compared to data obtained during a previous non-reported national study conducted in 1998 (TEF(WHO98)) in French lactaria (n=244). The mean of PCDD/Fs has decreased about 39.4% (18.8 pg TEQ(WHO98)/g lipids in 1998 vs 11.4 pg TEQ(WHO98)/g lipids in pilot study), respectively 41.5% for PCDDs (10.6 pg TEQ(WHO98)/g lipids in 1998 vs 6.2 pg TEQ(WHO98)/g lipids in pilot study) and 36.7% for PCDFs (7.9 pg TEQ(WHO98)/g lipids in 1998 vs 5.0 pg TEQ(WHO98)/g lipids in pilot study). For the sum of the 6 NDL-PCBs, the 2007 geometric mean concentration in milk was 176.3 ng/g lipids. The arithmetic mean lipid concentration in 2007 breast milk was 26.4 g/l (range from 6.0 to 46.7 g/l). A PCDD/F and DL-PCB daily intake was estimated to be 62.3 pg TEQ(WHO05)/kg body weight per day (85.0 pg TEQ(WHO98)/kg body weight per day) for a baby of 5 kg of body weight fed daily with 700 ml of maternal milk containing 25 g/l of lipids.