Per- and polyfluoroalkyl substance profiles revealed by targeted and non-targeted screening in European starling eggs from sites across Canada.

Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants including in wildlife but are a fraction of the growing 1000s of PFAS that are being produced. Our study objective was to determine and compare PFAS profiles using targeted analysis and non-targeted analysis (NTA) methods in European starling (Sturnus vulgaris) eggs collected in April/May of 2023 from 11 nesting box sites across Canada at locations described as landfills, near parks, forest, urban, near wastewater facilities, rural, waste management facilities and urban industrial. NTA revealed 41 PFAS at variable detection frequencies in eggs samples and up to 29 PFAS were quantifiable by targeted method analysis. The ΣPFAS mean concentration (range) (1048 (991-1078) ng/g ww) at the lone landfill site at Brantford were the highest whereas all other sites were <151 ng/g w.w. ΣPFAS concentrations were not significantly different (p < 0.05) among the 10 non-Brantford landfill sites including the Nova Scotia hospital site (range of 58.0-152 ng/g ww). Two side-chain fluorinated polymer surfactants for a sub-set of egg pools, and 4 emerging PFAS including GenX (or HFPO-DA), F-53B components and ADONA for all pools were not detectable. Confirmed against in-house synthesized standards, 8:2 FTOH sulfate, was detected in 93 % of all samples, and 6:2, 10:2, and 12:2 FTOH sulfates were also detected only in Brantford landfill site eggs. FTOHs, which are likely precursors of FTOH sulfate metabolites, were not detectable in any samples. This suggested that FTOH sulfate metabolites may be suitable biomarkers of exposure to FTOHs and perhaps other PFAS. Among all nest box locations, other additional NTA detected PFAS in eggs were e.g. branched isomers of PFOA, PFHpS, PFNS and PFDS and 6:2 diPAP. Overall, more targeted PFAS candidates should be monitored in starling eggs.