RESUMEN
Per- and polyfluoroalkyl substances (PFAS) are widely used in industry, residential, and consumer products. Studies have shown associations between high PFAS exposure and adverse health effects. In 2022, the National Academies of Science, Engineering, and Medicine (NASEM) published Guidance on PFAS Exposure, Testing, and Clinical Follow-up providing laboratory and clinical direction. The Guidance suggests nine PFAS should be measured in serum or plasma specimens and summed to provide a total PFAS concentration using a NASEM-recommended method. Follow-up clinical recommendations are based on the calculated PFAS NASEM summation. We developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method in accordance with NASEM recommendations but distinguished by the ability to separate closely related structural isomers. As part of our validation, PFAS prevalence was evaluated in a population survey comprised of clinical donor and remnant specimens (n = 1023 in total). In this study, 82.2% of the specimens had PFAS NASEM summations of 2 to < 20 ng/mL and 2.5% had a summation ≥ 20 ng/mL. The median PFAS NASEM summation was 4.65 ng/mL in this study, lower than the 7.74 ng/mL median observed in the 2017-2020 Centers for Disease Control and Prevention, National Health and Nutrition Examination Survey (n = 3072). This lower median PFAS NASEM summation may reflect a decline in PFAS population levels over time or sample population exposure differences.
RESUMEN
Although kombucha is a popular fermented beverage, the presence of alcohol markers has not been well studied despite being potential indicators of unintentional impairment. Ethyl glucuronide (EtG) and ethyl sulfate (EtS) were measured in oral fluid and urine collected after consumption of regular or hard kombucha. Participants drank within 20 min and provided all urine voids for 12 h, the first urine voids on days 2 and 3 and oral fluid specimens at fixed time points for 48 h. Screening employed liquid chromatography-tandem mass spectrometry (LC-MS-MS; EtS, 25 ng/mL cutoff [oral]; 100 ng/mL cutoff [urine]; EtG, 500 ng/mL cutoff [urine] and immunoassay (IA; EtG, 500 ng/mL cutoff [urine]). After consuming regular kombucha (n = 12 participants), EtS was not detected in oral fluid but both markers were detected by LC-MS-MS in urine specimens within the first five voids from 83% of participants with median (range) concentrations of 240 (100-3,700) ng/mL for EtS and 830 (530-2,200) ng/mL for EtG. Neither marker was positive by IA nor LC-MS-MS after day 1. After consuming hard kombucha (n = 7 participants), 2 (2.8%) of the 70 collected oral fluid specimens tested positive for EtS 3 h after consumption; however, 21 (30%) had EtS levels above the limit of detection (LOD, 10 ng/mL) after 0.5-8 h. Both markers were detected in urine specimens from all participants with median (range) concentrations of 3,381 (559-70,250) ng/mL for EtS and 763 (104-12,864) ng/mL For EtG. Urine specimens were negative for EtG and EtS by the end of the 48-hour study.