In the McDonough laboratory, we are investigating how organic contaminants impact aquatic ecosystems and human health by combining innovative environmental chemistry and bioanalytical techniques, state-of-the-art mass spectrometry, and field monitoring campaigns. Our work protects the public from exposure to harmful pollutants and draws attention to the global ubiquity of organic contaminants.
Current Research Projects
Bioaccumulation of Novel Per/Polyfluoroalkyl Substances (PFASs) from an Aqueous Firefighting Foam (AFFF) in a Mouse Model
Per- and polyfluoroalkyl substances (PFASs) are a global research priority because they have been found at levels exceeding various health advisory limits in the drinking water of millions of people. Aqueous firefighting foams (AFFFs) are a common source of complex mixtures containing hundreds of PFASs to drinking water. Understanding the full extent of human exposure to PFASs via these complex mixtures requires innovative analytical methodologies, including high-resolution mass spectrometry for suspect screening and nontarget analysis.
In this study, a mouse model was dosed with a commercial AFFF mixture. Serum and urine samples from dosed mice were analyzed by quadrupole time-of-flight mass spectrometry (QToF-MS). Suspect screening was conducted using an extensive in-house extracted ion chromatogram (XIC) list and fragmentation library for hundreds of AFFF-associated PFASs. Screening of serum revealed that several substituted perfluoroalkyl sulfonates, for which no toxicological data is available, were enriched in blood from AFFF-dosed mice.
Screening of urine revealed a mixture of PFASs distinct from those accumulating in the blood, with normalized peak areas increasing steadily over the exposure period. Additionally, non-target analysis of mouse serum revealed the presence of fluorinated compounds that were not included in the original suspect screening list and had not been detected previously in the AFFF product. This highlights the use of in vivo models as an effective tool for prioritizing novel bioaccumulative PFASs that may be overlooked because they are minor components in drinking water and AFFF products.
Related Publications
McDonough, C. A.; Guelfo, J. L.; Higgins, C. P. Measuring total PFASs in water: The tradeoff between selectivity and inclusivity. Current Opinion in Environmental Science & Health. 2018. 7, 13-18. DOI: 10.1016/j.coesh.2018.08.005.
McDonough, C. A., Choyke, S., Ferguson, P. L., DeWitt, J. C., Higgins, C. P. 2020. Bioaccumulation of novel per- and polyfluoroalkyl substances in mice dosed with an aqueous film-forming foam. Environ. Sci. Technol., 54, 5700-5709. DOI: 10.1021/acs.est.0c00234.
McDonough, C. A.; Ward, C.; Hu, Q.; Vance, S.; Higgins, C. P.; DeWitt, J. Immunotoxicity of an electrochemically fluorinated aqueous film-forming foam mixture. Tox. Sci. 2020. 178 (1) 104-114. DOI: 10.1093/toxsci/kfaa138
The PFAS-AWARE Study: PFASs in Drinking Water and Human Serum from an AFFF-Impacted Community in El Paso County, CO
PFASs have become ubiquitous water pollutants due to their remarkable persistence. More information is rapidly needed to understand health risks posed by widespread, long-term contamination of drinking water by PFAS-containing aqueous firefighting foams (AFFFs).
This study investigated PFAS contamination of public water systems in El Paso County, Colorado. Wells in this area were found to be contaminated with PFASs from AFFF above EPA health advisory levels between 2013 and 2016. Raw drinking water and human serum from throughout this region were collected from April to June, 2018. Serum samples were re-collected from a subset of the initial cohort one year later to track changes in PFAS levels after exposure ended. All samples were analyzed via quadrupole time-of-flight mass spectrometry (QToF-MS) suspect screening to understand the extent of PFAS contamination in human blood resulting from this exposure. Data were screened for >1000 previously characterized and theoretical AFFF-associated PFASs using a high-resolution mass spectral (HRMS) library and an extensive extracted ion chromatogram (XIC) list.
Suspect screening of drinking water samples using HRMS libraries tentatively revealed the presence of cyclic/unsaturated perfluoroalkyl sulfonates as well as sulfonamide precursors. Screening of human serum samples revealed that the average concentration of perfluorohexane sulfonate (PFHxS; 25 ng/mL) was elevated compared to the general population as well as most previous data from impacted communities, and showed that C5-C8 sulfonates were prominent and ubiquitous in blood from residents. Suspect screening suggests the presence of additional PFASs, such as chloro- and oxy-PFSAs that have previously been seen in blood from occupationally-exposed firefighters.
Related Publications
Barton, K.; Starling, A.; Higgins, C. P.; McDonough, C. A.; Calafat, A.; Adgate, J. Sociodemographic and behavioral determinants of serum concentrations of per- and polyfluoroalkyl substances in a community highly exposed to aqueous film-forming foam contaminants in drinking water. Int. J. Hyg. Environ. Health. 2019. In press. DOI: 10.1016/j.ijheh.2019.07.012
Past Projects
Depth profiles of Organophosphate Flame Retardants in the Remote Ocean
Dissolved organophosphate esters and polybrominated diphenyl ethers in remote marine environments: Arctic surface water distributions and net transport through Fram StraitPassive sampling to Understand Contaminant Dynamics in the Great Lakes
Spatial distribution and air–water exchange of organic flame retardants in the Lower Great Lakes
Significance of Population Centers As Sources of Gaseous and Dissolved PAHs in the Lower Great Lakes
I am a new Ph.D. student in the Department of Chemistry at Carnegie Mellon University. As an undergraduate, I studied both chemistry and chemical biology, and my research focused on the effects of the environment on archaeological samples. I’m looking forward to transferring those lab skills to studying the effects of per/polyfluoroalkyl substances (PFAS) on the environment and biological systems. When I’m not in the lab, I enjoy horseback riding, reading, and hiking!
I am currently a first year Ph.D. student in the Chemistry Department at Carnegie Mellon University. I have a background in Environmental Science (Siena College, B.S.) and am interested in the fate of organic contaminants in the environment. I am particularly interested in the bioaccumulation of per/polyfluoroalkyl substances (PFASs) throughout aquatic food webs and aquatic ecosystems. Outside of the lab, I enjoy reading, embroidery and spending time outside!
I am a rising second-year PhD student in the Department of Chemistry at Carnegie Mellon University. I earned my M. Phil degree from Hussain Ebrahim Jamal Research Institute of Chemistry at the University of Karachi, Pakistan. During my previous research, I focused on method development using HPLC-ELSD to rapidly screen secondary metabolites derived from plants.
I am an environmental chemist from India, currently in the second year of my Ph.D. at Carnegie Mellon University. I am interested in the fate of organic pollutants in the environment and my work focuses on understanding per- and polyfluoroalkyl substances (PFAS) contamination trends in aquatic animals and environments. I am working on evaluating passive sampling strategies to measure the bioavailable fraction of PFAS in marine sediments. Outside of working in the lab, I enjoy badminton, hiking, and hanging out with my dog, Rocket!
Morgan Van Der Linde
Yanan received her M.S. and Ph.D. degrees in Environmental Engineering from Fudan University, China. She also completed an 18-month joint-Ph.D. training program at Aalborg University, Denmark. Her research focuses on the environmental fate, risks, and degradation mechanisms of emerging environmental micropollutants, including DBPs, PPCPs, and microplastics.
Dilani received her B.S. degree (with honors) in Chemistry from the University of Colombo, Sri Lanka in 2016, and her M.S. and Ph.D. degrees in Chemistry from the Florida International University in 2021 and 2022, respectively. She joined the McDonough lab in 2023 as a postdoctoral scientist.
I am a Fulbright-Nehru Postdoctoral fellow working in the area of Environmental chemistry and engineering at the McDonough lab, Department of Chemistry, Carnegie Mellon University. I received PhD in Soil Science and Agricultural Chemistry from Indian Agricultural Research Institute, New Delhi, India (2018). Prior to joining McDonough lab, I was a Soil Scientist at Central Soil Salinity Research Institute, Karnal, India. Currently, my research works focus on development of engineered clay mineral adsorbents using naturally available clay minerals and biowastes to remove PFAS from contaminated water and reducing PFAS bioavailability in food crops, deciphering an inexpensive and green PFAS remediation method.
I am a chemical oceanographer and analytical chemist working at the intersection of environmental analytical chemistry, environmental health engineering, and toxicology. I received my B.Sc. in Chemistry from the Massachusetts Institute of Technology (MIT) in 2008, and my Ph.D. in Chemical Oceanography from the University of Rhode Island Graduate School of Oceanography (URI GSO) in 2017. I completed a postdoctoral fellowship at Colorado School of Mines developing methods for nontarget analysis of per/polyfluoroalkyl substances (PFASs) in biological samples. I use cutting-edge environmental monitoring and analytical chemistry techniques to study the fate, transport, and biological effects of anthropogenic organic contaminants in aquatic environments. Broadly, I am interested in how the molecular structure and chemical properties of pollutants influence their fate in the environment, as well as their biological effects in aquatic organisms and humans. My overarching objective is to understand human and ecosystem health risk associated with organic contaminants in water and to identify particular compounds of concern that should be prioritized for remediation and toxicological investigation. When I’m not working, I am usually brewing beer and hanging out with my dogs, Millie (pictured here) and Pickles.
