Carla Ng, PhD

Assistant Professor

Chemical & Petroleum Engineering (Secondary)

203 Benedum Hall | 3700 O’Hara Street | Pittsburgh, PA 15261 P: 412-383-4075

carlang@pitt.edu www.pitt.edu/~carlang

Chemical Fate in the Anthropocene

Human influence on the environment has reached geologic scales, prompting a call to label our current epoch the “Anthropocene.” Our group studies how human activity interacts with physiological and ecological systems to drive the movement of hazardous chemicals and thereby affect human and environmental health. We use a variety of complimentary approaches, including multimedia environmental fate models, physiologically based toxicokinetic (PBTK) models for organisms, and in vitro assays to understand and predict the distribution of legacy and emerging organic chemicals. Chemicals of particular interest include per- and polyfluorinated alkyl substances (PFAS), current-use pesticides, and chemicals like flame retardants that find their way into food by accumulation from the environment or via food production, processing or packaging. We also use and develop quantitative structure-activity relationships (QSARs) to predict environmental hazards of new chemicals and screen existing chemicals for substances of concern.

Global Food Trade as a Chemical Exposure Route

Food is a basic human need and also part of a complex system with social, environmental, and economic implications. One critical dimension of this system is chemical contamination. Food is a major pathway of human exposure to chemicals, and food production causes substantial contamination to surrounding environments. We use an integrated modeling strategy, combining substance flow analysis, regional bioaccumulation and global chemical fate models to investigate how site-specific emissions intersect with global trade patterns to influence human exposure to hazardous chemicals. Our group recently showed how globally traded fish feed plays an outsized role in determining flame retardant concentrations in farmed salmon (see cover article in the June 19 issue of Environmental Science & Technology). Ongoing work compares seafood origin to dietary exposure contributions for this key class of toxic chemicals.

What Makes a Chemical Bioaccumulative?

Per- and polyfluorinated alkyl substances (PFAS) are a class of extremely persistent contaminants increasingly found in the environment, humans, and wildlife on a global scale. PFAS redefined our understanding of bioaccumulation due to their unique toxicokinetics and tissue distributions. Students in my group are developing novel PBTK models that successfully describe PFAS behavior through their interactions with proteins and membrane transporters. We build predictive models for the many thousands of PFAS for which few data are available by combining molecular dynamics simulations with in vitro assays, providing guidance for ongoing policymaking and remediation efforts.