Polycyclic Aromatic Hydrocarbon Residues in Human Milk, Placenta, and Umbilical Cord Blood in Beijing, China

This paper provides the results of an investigation on dietary intakes and internal doses of polycyclic aromatic hydrocarbons (PAHS) nonsmoking women from Beijing, China. Concentrations of PAHs were measured by gas chromatography/mass spectrometry (GC/MS) for human, milk, placenta, and umbilical cord blood samples from 40 nonsmoking women::: and for 144 composite food samples covering major food categories. Informattion on food consumption and estimated ingestion doses of PAHs by the cohort was also collected individually. Relationship among the studied human sarnpies, and relative importance of breastfeeding to the total exposure dose of infants,71 were addressed. The median (mean and standard deviation) total concentrations of 15 PAHs in human milk, placenta, and umbilical cord blood with without) fat normalization were 278 (9.30 +/- 5.75), 819 (35.9 +/- 15.4), and (5.521 +/- 3.71) ng/g of fat, respectively, and the corresponding levels. of,. benzo[a]pyrene equivalent equiv, (B[a]P(equiv)) were 11.2 (0.473 +/- 0.605), 16.2 (0.717 +/- 0.318), and 13.1 (0.140 +/- 0.225) ng/g of fat, respectively. The calculated intake of B[a]P(equiv) by Beijing cohort varied from 0.609 to 4.69 ng . kg(-1) day(-1) with a median value of 1.93 (2.09 +/- 0.921 mean +/- standard deviation) ng.kg(-1). day(-1). Significant correlations were found among human milk, placenta, and umbilical cord blood (p < 0.05) for low-molecular-weight PAHs, indicating selective transfer potential of individual PAHs from mother to fetus. Internal dose of PAHs was not in proportion to amounts of food ingestion, daily dietary intake, lifestyle, and social-demographic characteristics of the participants (p > 0.05). Ingested doses of PAHs (3.00-102 ng . kg(-1). day 1), which were much higher than the inhaled doses (0.152-8.50 ng . kg(-1) . day(-1)), were 3-4 orders of magnitude lower than the recommended reference doses, unlikely to impose any obvious risk based on current knowledge.