PCDD and PCDF exposure and levels in humans in Germany.

Abstract

For nonoccupationally exposed persons, the daily intake via food consumption has been calculated to be 0.35 pg/kg body weight per day for 2,3,7,-tetrachlorodibenzo-p-dioxin (TCDD) and 2.3 pg/kg body weight per day for TCDD equivalents (TEqs). As compared to food, other sources and pathways are of minor importance. Food of animal origin contributes most, although human exposure begins with atmospheric emissions depositing these compounds on plant surfaces. In the meantime, a possible additional body burden from cardboard containers for cow's milk and coffee filters has been practically excluded. Ofthe 210 existing PCDDs and PCDFs, only 15 2,37,8-substituted isomers with a characteristic congener pattern can be found in samples of human origin. In adipose tissue and milk samples, mean levels for 2,3,7,8-TCDD of 7.2 and 3.6 pg/g fat, respectively, and of 56 (range 18-122) and 30 (range 10-72) pg TEqs/g fat, respectively, were determined. Human data revealed a dependency of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/PCDF) levels on age. In human milk, levels became reduced with the number of children born to mothers and duration of breast-feeding period. The average daily intake for a breast-fed child has been calculated to be 17 pg 2,3,7,8-TCDD/kg body weight per day and 142 pg TEqs/kg body weight per day, respectively. Levels in adipose tissue of infants, even ifbreast fed, were distinctly lowercompared to human milk. In human milk, adipose tissue, and whole blood, PCDD/PCDF concentrations have been found to be equal on a fat-weight basis. Liver fat accumulated PCDD/PCDF with an alteration in the congener distribution pattern, whereas brain, even on afat-weight basis, showed the lowest concentrations. Elevated or even high levels were found in occupationally exposed persons working in special chemical plants or involved in specific processes. There are limited data suggesting slightly elevated PCDD/PCDF levels are due to longterm consumption ofa large share of food produced near point sources with a heavy emission or ingestion ofsoil or dust from such areas.

Body Loadings and Health Risk Assessment of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans at an Intensive Electronic Waste Recycling Site in China

“…Others studies also revealed such result (36,38). In contrast, Beck et al (35) and Iida et al (39) reported dioxin levels in human milk from primiparae were higher than multiparae. TEQ values in human milk from the dumping site of India showed a negative correlation with the number of deliveries (38).…”

Nurturing and Breast-Feeding: Exposure to Chemicals in Breast Milk

“…There was an obvious decrease of the dioxin levels in human milk with an increasing number of nursing periods (26): at the time of the second nursing period, the mean decrease of TEq concentrations was 22% and when the third child was nursed, 43%. Within the nursing period, a decrease of the dioxin level (TEq) by 15% was measured after 6 weeks and by 25% after 12 weeks (26,27 (29).…”

Estimating perchlorate exposure from food and tap water based on US biomonitoring and occurrence data

“…Dioxin-like chemicals are measurable in U.S. meats and poultry (Hoffman et al, 2006) as a result of the accumulation of these substances in the food chain. Breast milk is a substantial source of exposure for infants (Beck et al, 1994;, though breast milk levels have been decreasing in recent years (Arisawa et al, 2005). The lesser chlorinated PCBs, including some dioxin-like PCBs, are more volatile.…”