Evaluation of dioxin-like chemicals in pooled human milk samples collected in Australia

DesignHuman milk samples were collected and analysed for the levels of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and selected dioxin-like polychlorinated biphenyls (PCBs). In total, 157 individual samples collected during 2002 and 2003 as well as 24 samples collected in 1993 were analysed as 20 pools.ResultsPCDDs, PCDFs and dioxin-like PCBs were detected in all pooled samples. For samples collected during 2002/2003, the TEQDFP ranged from 6.0 to 15.2 pg TEQ g−1 lipid with an average of 9.0 pg TEQ g−1 lipid. The average lipid content was 3.7 ± 0.5%. No systematic differences were observed in the levels of PCDDs, PCDFs and PCBs in human milk samples collected from different regions of Australia during 2002/2003.For samples collected in 1993 and analysed as pools, the mean level, expressed as TEQDFP was 16 ± 1.4 pg TEQ g−1 lipid. The average lipid content was 3.9 ± 0.7%.ConclusionThe levels of PCDDs, PCDFs and dioxin-like PCBs in the human milk of Australian women are both low compared to international levels and similar across all regions of Australia. Consistent with world-wide trends, the levels of PCDDs, PCDFs and dioxin-like PCBs have decreased over a 10 year period from 1993 to 2003 by approximately 40%.