CALUX Determination of PCDD/F's and Dioxin-Like PCB's in Small Amounts of Human Milk from the Rural Areas of Flanders (Belgium) Using the H1l7.5c1 Mouse Hepatoma Cell Line

In the first Flemish Environment and Health survey run by the Flemish Centre of Expertise on Environment and Health (FLEHS I 2002-2006) increased concentrations of PCBs, dioxin-like substances and chlorinated pesticides (a metabolite of DDT and hexachlorobenzene) were observed in cord blood of newborns and in blood of 14-15 year-old adolescents and 50-65 year-old adults living in low populated rural communities of East and West Flanders and Flemish Brabant compared to other Flemish regions. Due to the health concern associated with chlorinated compounds follow-up of pollutant levels in this area is of importance. Therefore, human breast milk from mothers living in these regions was collected (2009-2010) for analysis of different POPs. For the quantification of PCDD/Fs and/or dioxin-like PCBs in (human) milk samples both GC-HRMS and the CALUX bioassay are used in routine analysis. However, most CALUX methods use high amounts of milk (varying between 10 and 60 mL)1, 2. Since for the Flemish human breast milk survey in the rural areas not only PCDD/F and dioxin-like PCBs were analyzed, but also other POPs like DDE, PBDEs, marker PCBs, HCB, HCH, perfluorinated compounds, etc., the amount of milk available for the CALUX bioassay was limited. Therefore, a new method was developed for the analysis of PCDD/Fs and dioxin-like PCBs in only 5 mL milk.