DETERMINANTS OF POLYCHLORINATED BIPHENYL LEVELS IN PLASMA FROM 42-MONTH-OLD CHILDREN

We report on the PCB levels in plasma from 42-month-old children and t he factors that determine these levels. We measured the levels of the PCB congeners 118 (2,4,5-3'4' pentachlorobiphenyl (CB)), 138 (2,3,4-2' 4'5'hexaCB), 153 (2,4,5-2'4'5'hexaCB), and 180 (2,3,4,5-2'4'5'heptaCB) in cord plasma, breast milk, and plasma from 42-month-old children (n = 126) living in the Groningen area, The Netherlands. The sum of the levels of these four congeners was calculated for cord plasma (Sigma P CBcord), breast milk (Sigma PCBmilk), and 42-month plasma (Sigma PCB42 mo). Sigma PCBcord was used as a measure of prenatal exposure. Postnat al exposure was assessed in terms of the Sigma PCBmilk and the duratio n of lactation. In addition, maternal factors including age, body weig ht and height, parity, and formal education were recorded. In 42-month -old children who have been fully breast-fed for at least six weeks as babies, the median Sigma PCB42mo was 4.5 times as high as that in for mula-fed children (0.81 mu g/L vs. 0.18 mu g/L). The PCB levels in cor d blood and human milk and the duration of breast-feeding predict the plasma PCB level at 42 months. Each additional week of full breast-fee ding is estimated to result in an increase of 0.3% of the milk PCB lev el. We concluded that lactation is a major source for the child's PCB body burden at 42 months.