Serum dioxin levels in Sydney Harbour commercial fishers and family members

Abstract

Background Commercial fishing in Sydney Harbour (SH) was banned in February 2006 as a result of high dioxin levels in some SH seafood. Because of concerns by some fishers about their own dioxin levels, testing of serum dioxin levels was offered to SH commercial fishers and their families. Objectives Aims of this study were to describe blood dioxin levels of SH fishers and family members; compare these levels to background Australian levels and international data; analyze association between intake of SH seafood and dioxin levels; and assess whether blood dioxin levels were useful to inform ongoing care of SH fishers. Methods NSW Department of Health conducted clinics at which 112 fishers and family members gave blood for analysis of dioxin levels. Dioxin exposure was assessed through a questionnaire. Seafood dioxin levels were provided by the NSW Department of Environment and Climate Change. Results For the fishers ( n = 26), median TCDD and total TEQ levels were 27.3 and 62.4 pg g −1 lipid, respectively. For the whole group ( n = 112), median TCDD and total TEQ levels were 9.3 and 26.1 pg g −1 lipid, respectively. Age was the strongest predictor of increased dioxin levels ( p < 0.01), and consumption of SH seafood was also strongly associated ( p = 0.01). Conclusions Serum dioxin levels in the SH fisher cohort were higher than Australian background levels, but comparable with other international high fish-eating communities, and lower than occupationally and accidentally exposed cohorts. High TCDD levels in commonly eaten seafood by the SH fishers confirms this as the likely exposure source.