Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in breast milk of first-time Irish mothers: Impact of the 2008 dioxin incident in Ireland Iona S. Pratt a,⇑ , Wayne A. Anderson a , Dominique Crowley b , Sean F. Daly c , Rhodri I. Evans a , Alwyn R. Fernandes d , Margaret Fitzgerald b , Michael P. Geary e , Declan P. Keane f , Rainer Malisch g , John McBride h , John J. Morrison i , Alan Reilly a , Christina Tlustos a a Food Science and Standards Division, Food Safety Authority of Ireland, Lower Abbey Street, Dublin 1, Ireland b Public Health Medicine, HSE East, Dublin, Ireland c Coombe Women’s Hospital, Dublin 8, Ireland d Food and Environment Research Agency (FERA), York, UK e Department of Obstetrics and Gynaecology, Rotunda Hospital, Dublin 1, Ireland f Department of Obstetrics, National Maternity Hospital, Dublin, Ireland g State Institute for Chemical and Veterinary Analysis of Food, Bissierstrasse 5, Freiburg, Germany 1 h The State Laboratory, Backweston Campus, Co. Kildare, Ireland i Department of Obstetrics and Gynaecology, University College Hospital Galway, Galway, Ireland article info Article history: Received 11 July 2011 Received in revised form 6 March 2012 Accepted 31 March 2012 Available online 5 May 2012 Keywords: Human milk PCDD/Fs PCBs Irish dioxin incident abstract The 2008 dioxin incident in Ireland resulted in elevated concentrations of polychlorinated dibenzo-p- dioxins (PCDDs), dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in Irish pork and pork products, due to the consumption of contaminated animal feed by pigs. In order to investigate any result- ing impact on the Irish population, these contaminants were measured in pooled breast milk samples from 109 first-time mothers, collected in 2010. A comparison of the results with similar data from 2002 revealed generally lower concentrations of PCDD/Fs and dioxin-like PCBs in the 2010 samples, con- firming the declining trend reported by many authors. Contaminant concentration levels for both 2002 and 2010 were generally slightly lower than those reported internationally, with a mean combined PCDD/F and PCB WHO-TEQ of 9.66 pg g À1 fat, for an overall pooled sample of milk from 2010. An appar- ent slight increase in PCDFs was observed between 2002 and 2010 (from 2.73 pg WHO-TEQ g À1 fat to 3.21 pg WHO-TEQ g À1 fat), with the main contributory congener being 2,3,4,7,8-PentaCDF. While it can- not be totally discounted that the slight increase in 2,3,4,7,8-PentaCDF and in the overall PCDF WHO-TEQ in breast milk could be attributable to consumption of Irish pork during the 2008 incident, we consider that it is more likely that this was due to other factors, including the predominantly urban/industrial sampling locations for the 2010 samples, compared to 2002. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction The polychlorinated dibenzo-p-dioxins (PCDDs) and polychlori- nated dibenzofurans (PCDFs) are persistent organic pollutants (POPs) formed during combustion processes and as by-products of industrial processes (Cleverly et al., 2007; Fiedler, 2007). Poly- chlorinated biphenyls (PCBs) are industrial chemicals that have been used in, e.g. transformers, lubricants, plasticisers and inks, although their use has now largely been phased out (ASTDR, 2001). The PCDDs, PCDFs and PCBs are toxic chemicals that can cause serious health effects such as cancer, hormone disruption, impaired reproduction, skin toxicity and immune system disor- ders, when exposure continues over an extended period (IARC, 1997; Kogevinas, 2001; JECFA, 2002). Up to 90% of human exposure to dioxins results from the consumption of food containing dioxins, mainly foodstuffs of animal origin with a high fat content such as meat and fish, since these lipophilic contaminants accumulate in fatty tissues (Gilman et al., 1991; Fürst et al., 1992; Päpke, 1998; EFSA, 2010). Numerous studies have been carried out on concentrations of POPs in human breast milk as an indicator of body burden since the first reports of accumulation of these contaminants in exposed populations appeared in the scientific literature. Concentrations of lipophilic POPs in breast milk are influenced to a large extent by 0045-6535/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.chemosphere.2012.03.095 ⇑ Corresponding author. Tel.: +353 1 8171355. E-mail address: ipratt@fsai.ie (I.S. Pratt). 1 Reference laboratory of the 3rd round of the WHO study. Chemosphere 88 (2012) 865–872 Contents lists available at SciVerse ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere