Residue analyses and exposure assessment of the Irish population to nitrofuran metabolites from different food commodities in 2009–2010

Abstract

An exposure assessment to nitrofuran residues was performed for three human populations (adults, teenagers and children), based on residue analyses of foods of animal origin (liver, honey, eggs and aquaculture) covering the 2-year period 2009–2010. The occurrence of nitrofuran metabolites in food on the Irish market was determined for the selected period using the data from Ireland’s National Food Residue Database (NFRD) and from results obtained from the analysis of retail samples (aquaculture and honey). Laboratory analyses of residues were performed by methods validated in accordance with Commission Decision 2002/657/EC regarding performance of the analytical method and interpretation of results. Semicarbazide (SEM) was the contaminant most frequently identified and its content ranged from 0.09 to 1.27 μg kg⁻¹. SEM is currently used as a marker of nitrofuran abuse, but it may also occur from other sources. The presence of nitrofuran metabolite 3-amino-2-oxazolidinone (AOZ) was detected in two aquaculture samples (prawns) at 1.63 and 1.14 μg kg⁻¹, but such a low number of positive cases did not present sufficient data for a full AOZ exposure assessment. Therefore, the evaluation of exposure was focused on SEM-containing food groups only. Exposure assessments were completed using a probabilistic approach that generated 10 iterations. The results of both the upper- and lower-bound exposure assessments demonstrate that SEM exposure for Irish adults, teenagers and children from selected food commodities are well below EFSA-estimated safe levels.

Keywords:

• probabilistic exposure assessment
• nitrofuran metabolites
• residue determination
• UHPLC-MS/MS
• liver
• aquaculture
• honey
• food consumption database
• semicarbazide

Acknowledgements

The authors Anita Radovnikovic and Emma-Rose Conroy contributed equally to the work in this paper. Dr Rhodri Evans (Food Safety Authority of Ireland) and Dr. Michael O’Keeffe (formerly Teagasc) are acknowledged for technical input into this paper.

Funding

This research was funded by the Food for Health Research Initiative (FHRI) administered by the Irish Department of Agriculture, Food and the Marine and the Health Research Board (Contract 07FHRIAFRC5).