Seafood Intake and Serum Levels of Polychlorinated Biphenyls in Mother and Child

Background and objectives Seafood is considered a natural part of a healthy and balanced diet. Seafood is an excellent source of high quality protein, and contains many essential nutrients like omega-3 fatty acids, vitamin D, B12, iodine, and selenium. At the same time it contains some environmental contaminants, such as polychlorinated biphenyls (PCBs), which may have undesirable health effects. The risk-benefit of seafood is therefore under debate, with focus on oily fish in particular. Based on this public debate the Norwegian Directorate of Health recently advised young, as well as pregnant women, to consume no more than two meals of oily fish per week over longer periods of time. This might reduce the foetal exposure to PCBs that can have a negative effect on development. The National Institute of Nutrition and Seafood Research (NIFES) did not support this advice, as it was based on contaminant data from 2004, and contaminant levels have decreased since then. In this project mothers’ seafood intake during pregnancy and postpartum was assessed, and serum concentrations of PCBs from both mother and child have been determined. The relationship between PCB-concentrations in mother and child and reported seafood intake was then evaluated. Confounding factors for body burden of PCBs, like BMI, age, breastfeeding, and parity, were also examined to see if they had an influence on the PCB-concentrations. Method This project was part of the prospective longitudinal population-based study “Nutrition, Mental Health and Infant Development” that took place in the municipality Fjell in Western-Norway, 2010-2012. Blood was sampled from mothers in the 28th gestation week and at 3-, 6- and 12 months after birth from both mother and child. Dietary habits of mothers were assessed by a seafood-food frequency questionnaire (seafood-FFQ), and dietary habits of the children were assessed by a 24-hour recall interview and an interviewer administrated FFQ. The following PCBs: PCB-118, PCB-138, PCB-153 and PCB-180 were extracted from 100 μl serum and analysed by High Resolution Gas Chromatography – High Resolution Mass Spectrometry (HRGC-HRMS). Results and conclusion The women in this study population consumed less seafood than the amount recommend by the Norwegian Directorate of Health. All four PCBs were detected in serum from both mother and child, at levels considerably lower than other European countries. Whereas breastfeeding in itself had little impact on the serum PCB-levels in mothers, breastfed children had increased iv serum PCB-levels compered to not breastfed children. The serum PCB-levels increased with age and parity in non-breastfeeding and breastfeeding women respectively. Fish liver consumption was the only seafood that decisively had an impact on serum PCB-levels. When excluding fish liver consumers there were no relationship between maternal fish intake and serum PCB-levels in mother or child. Pregnant and young women should therefore increase their seafood intake to achieve the overall beneficial health effects, but avoid consumption of fish liver