Exposure of breast-fed children in the Czech Republic to PCDDs, PCDFs, and dioxin-like PCBs.

Human milk samples from 81 mothers living in seven selected localities of the Czech Republic collected in 1999-2000 were analyzed for PCDDs, PCDFs, and dioxin-like PCBs. Significant local differences in total WHO-TEQ values were observed (median ranges: 27.8-64.6pg/g fat) with the highest level in Uherské Hradiště, but the highest PCDD-TEQ value was in Prague. Seven congeners (2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF, and PCBs 118, 126, 156, and 157) cover about 90-94% of the total TEQ level. The non- and mono-ortho PCBs account for approximately 50-70% of the total TEQ levels in individual groups. The calculated median daily intake of the total TEQ for breast-fed infants ranged from 271pg/kg b.w./day in Uherské Hradiště to 117pg/kg b.w./day in Liberec and exceeded by about two orders of magnitude a tolerable daily intake (TDI) of 1-4pg/kg b.w. recommended by the WHO. Our results confirmed significant local differences in the levels of dioxins and suggest that hot spot locations might exist within the country.