PROGRAMME

Per- and polyfluoroalkyl substances (PFAS) represent a group of man-made chemicals extensively utilized in various products for over five decades. These chemicals are renowned for their water- and stain-resistant properties, but their persistence in the environment raises concerns. PFAS can accumulate in the human body over time, even with minimal exposure. Pregnant women, in particular, face heightened vulnerability to PFAS exposure, as these compounds can traverse the placenta and impact the developing fetus. Such exposure during pregnancy has been associated with adverse health effects, including low birth weight, preterm birth, and developmental delays. The current analytical methods conventionally focus on a predetermined list of PFAS, potentially overlooking several compounds and leading to an underestimation of their hazards. Thus, there is an urgent demand for the development and application of wide-scope screening methodologies to detect and semi-quantify PFAS in human biomonitoring samples. In this study, 109 biological samples from pregnant women were collected in Spain, comprising placenta (n=23), serum (n=48), and urine (n=38). The samples were immediately subjected to generic sample preparation protocols upon arrival at the laboratory. Subsequently, liquid chromatography high-resolution mass spectrometry was employed for analysis. Quality assurance and control measures encompassed the use of 12 procedural blank samples (four for each matrix), analysis of pooled extracts during the chromatographic sequence, application of internal standards, and adherence to standard operating procedures to ensure instrumental mass accuracy, resolution, sensitivity, and chromatographic repeatability. The resulting data were converted to mzML format and uploaded to the NORMAN Digital Sample Freezing Platform (DSFP) for digital storage and retrospective suspect screening. To achieve a comprehensive PFAS characterization, the samples underwent retrospective suspect screening for 4,777 PFAS compounds, employing an approach initially developed for screening environmental samples. Remarkably, the application of cheminformatic tools and databases from environmental chemistry to exposome science proved highly successful, revealing a multitude of chemicals in the biomonitoring samples. Our findings strongly suggest that pregnant women are exposed to a variety of PFAS compounds, even at relatively low levels. Moreover, different PFAS were detected in the investigated matrices, highlighting the influence of their physicochemical properties on their fate. Further research is essential to develop a risk assessment prioritization scheme based on the risks of PFAS exposure to pregnant women.