Preliminary monitoring of the presence of perfluoroalkyl substances in Italian eggs from different breeding systems

Perfluoroalkylated substances (PFASs) are a wide cluster of fluorinated molecules largely engaged industrially and commercially for many purposes. Because of the strength of the fluorine-carbon bond, PFASs show a firm tenacity against thermal degradation, hydrolysis, photolysis and biodegradation. On the other hand, such chemical stability gives them persistent environmental pollutant feature. In 2012, EFSA published a scientific report on PFASs in food, mentioning their adverse effects on health. Based on observational studies evidences, EFSA has recommended a tolerable daily intake (TDI) for the two most known PFASs, i.e. PFOS 150 ng/kg b.w./day and PFOA 1500 ng/kg b.w./day. The aim of this study was to monitor, for the first time, the level of contamination of PFASs in chicken eggs laid in Northern Italy. The eggs were collected from different rearing systems, in order to search a correlation between this variable and the contamination of PFASs. In this study four PFASs [perfluoro-nnonanoic acid (PFNA), perfluoro-noctanoic- acid (PFOA), sodium perfluoro-1- hexanesulfonate (PFHxS) and sodium perfluoro- 1-octanesulfonate (PFOS)] were analyzed by liquid chromatography-tandem mass spectrometer (LC-MS/MS). 132 eggs were analyzed, split up in 11 groups according to the geographical origin and rearing system. Results accord with literature data available for chicken eggs: almost all the samples show a PFASs contamination level under the limit of quantification (LOQ) of 0.25 ng/mL. No significant difference results from the rearing system, attesting an equal distribution and a concentration of PFASs detectable under the limit of quantification.