Immunologic Effects of Background Exposure to Polychlorinated Biphenyls and Dioxins in Dutch Preschool Children 

Environmental Health Perspectives Volume 108, Number 12, Dec00

Nynke Weisglas-Kuperus,¹ Svati Patandin,¹ Guy A.M. Berbers,² Theo C.J. Sas,¹ Paul G.H. Mulder,³ Pieter J.J. Sauer,¹ and Herbert Hooijkaas⁴

¹Department of Paediatrics, Division of Neonatology, Erasmus University and University Hospital/Sophia Children's Hospital, Rotterdam, The Netherlands
²Department of Clinical Vaccine Research, National Institute of Public Health and the Environment, Bilthoven, The Netherlands
³Institute of Epidemiology and Biostatistics, Erasmus University, Rotterdam, The Netherlands
⁴Department of Immunology, Erasmus University and University Hospital, Rotterdam, The Netherlands

Abstract

Prenatal exposure to polychlorinated biphenyls (PCBs) and dioxins is associated with changes in the T-cell lymphocyte population in healthy Dutch infants. We investigated whether these changes persist into later childhood and whether background exposure to PCBs and dioxins is associated with the prevalence of infectious or allergic diseases and humoral immunity at preschool age. The total study group consisted of 207 healthy mother-infant pairs. We estimated prenatal exposure to PCBs and dioxins by the sum of PCBs 118, 138, 153, and 180 (PCB) in maternal and cord plasma and in breast-fed infants by the dioxin, planar, and mono-ortho PCB toxic equivalent (TEQ) levels in human milk. At 42 months of age, current body burden was estimated by the PCB in plasma. We assessed the prevalence of infectious and allergic diseases by parent questionnaire, and measured humoral immunity by antibody levels for mumps, measles, and rubella after primary vaccination. We performed immunologic marker analyses of lymphocytes in a subgroup of 85 children. Prenatal PCB exposure was associated with an increased number of lymphocytes, T-cells, and CD3CD8⁺ (cytotoxic), CD4⁺CD45RO⁺ (memory), T-cell receptor (TcR) ß⁺, and CD3⁺HLA-DR⁺ (activated) T cells and lower antibody levels to mumps and measles at preschool age. Adjusted for confounders, prenatal PCB exposure was associated with less shortness of breath with wheeze, and current PCB body burden was associated with a higher prevalence of recurrent middle-ear infections and of chicken pox and a lower prevalence of allergic reactions. A higher dioxin TEQ was associated with a higher prevalence of coughing, chest congestion, and phlegm. We conclude that in Dutch preschool children the effects of perinatal background exposure to PCBs and dioxins persist into childhood and might be associated with a greater susceptibility to infectious diseases. Common infections acquired early in life may prevent the development of allergy, so PCB exposure might be associated with a lower prevalence of allergic diseases. Key words: allergic diseases, antibody levels, breast-feeding, infectious diseases, leucocyte (sub)populations, PCBs, PCDDs, PCDFs. Environ Health Perspect 108:1203-1207 (2000). [Online 17 November 2000]

http://ehpnet1.niehs.nih.gov/docs/2000/108p1203-1207weisglas-kuperus/abstract.html

Address correspondence to N. Weisglas-Kuperus, Department of Paediatrics, Division of Neonatology, Sophia Children's Hospital, PO Box 2060, 3000 CB Rotterdam, The Netherlands. Telephone: 31-10-4636077. Fax: 31-10-4636811. E-mail: Weisglas@alkg.azr.nl

We thank C. Koopman-Esseboom for initiating the study and for collecting the maternal and cord samples; L. Birnbaum, R. Smialowicz, and J.E. Vos for critically reviewing this paper; and all parents and their children for participating in this study.

This study is part of the Dutch PCB/Dioxin Study, a larger prospective longitudinal study on possible adverse health effects of these pollutants on human children, and was supported by the Dutch Toxicology Research Promotion Program and the European Commission for Environmental and Health Programs contract EV5V-CT92-0207.

Received 28 March 2000; accepted 18 July 2000

Extract from Conclusion:

In conclusion, the effects of perinatal background exposure to PCBs and dioxins persist into childhood and might be associated with a greater susceptibility to infectious diseases. Common infections acquired early in life may prevent the development of allergy, and therefore PCB exposure might be associated with a lower prevalence of allergic diseases. In our study the negative effect of a higher postnatal PCB exposure was counteracted by the positive effect of a longer duration of breast-feeding in infancy. Moreover, as described previously, breast-fed children in our study did better in neurological (30) and cognitive outcome (18) than their formula-fed counterparts did. Our study does not provide data to discourage breast-feeding at present background PCB levels. Although most of the above-mentioned immunologic changes seen in preschool children may be subtle, these data indicate that human children might be susceptible to immunotoxic pollutants and that, due to present levels of PCBs and dioxins in the food chain, health effects may occur. These effects are important from a public health perspective because large population groups are exposed. Perinatal exposure to PCBs, dioxins, and related compounds should therefore be lowered by reducing the intake through the food chain at all ages, rather than by discouraging breast-feeding. Long-term follow-up studies of perinatally exposed cohorts should be conducted into later childhood, through puberty, and into adulthood to investigate the implications of our findings.