Virginia Via Research Day Book 2026

Medical Student Research Biomedical

22 DIFFERENCES IN CRANIOFACIAL MEASUREMENTS OF MOUSE EMBRYOS THROUGHOUT GESTATION WITH QUATERNARY AMMONIUM COMPOUND EXPOSURE

Kayah Tucker 1 , OMS II; Ashley Jordan 1 , OMS III; Dylan Davis 1 , BS; Terry C. Hrubec 1,2 DVM PhD Corresponding author:ktucker@vcom.edu

1. VCOM-Virginia, Blacksburg, Virginia 2. Virginia-Maryland College of Veterinary Medicine, Virginia Tech Quaternary ammonium compounds (QACs), otherwise known as quats, are a large class of chemicals that serve as common ingredients in disinfectants, soaps, laundry detergents, and other personal care products. Widespread use of QACs has accelerated in the past decade, especially in response to the rise of COVID-19, as evidenced by its detection in household dust, wastewater, and even human tissue and breastmilk.1 Emerging evidence on the negative impacts to human health have warranted reassessment of the risks and benefits to the production, use, and disposal of QACs. Our team has recently shown that QACs are not only reproductive toxicants and developmental teratogens, but act as inhibitors of mitochondrial function and cholesterol synthesis. Embryonic exposure to QACs at the time of neural tube closure results in a neural tube defect (NTD). Additionally, embryos dosed with QACs reflect an abnormal phenotype, which

suggests malformation independent of NTD. To further characterize this malformation, we conducted two systematic evaluations of morphological differences in embryos and later gestational fetuses. The fetal data is presented here. CD-1 mice were dosed with 60 mg/kg/day Alkyldimethylbenzyl ammonium chloride + Didecyldimethyl ammonium chloride (ADBAC+DDAC) in the feed throughout breeding and gestation. Fetuses were evaluated for maxillary and mandibular lengths, palate widths, and crown to rump lengths on gestational day (GD) 12, GD14, and GD16. Statistical differences were determined by a two-sample T-test. Reduced maxillary and mandibular lengths were observed in exposed fetuses, and cleft palates were observed in GD16 fetuses. Previous analysis of the GD10 embryos identified a smaller pharyngeal arch area in exposed embryos. We believe that the reduced craniofacial measurements in the fetuses

occurred due to reduced neural crest migration into the developing maxillary and mandibular prominence's of pharyngeal arch I. It was expected that this would result in observable micrognathia and cleft palate. This study aims to illustrate that those phenotypic changes seen at GD10 persist through later gestational ages, independent of NTD formation. This research is important as studies have found that 100% of people evaluated after the COVID-19 pandemic had QAC residues in their blood. This indicates that we are repeatedly exposed most likely on a daily basis. Consequently, our findings aid in bridging the gap in our understanding of the teratogenic nature of QACs and the harmful impact that these chemicals have on our most vulnerable populations.

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