Chemistry, Fate, and Impact of Emerging Contaminants of Concern

Overview

We study how microplastics, tire wear, and brake wear particles interact with clouds and precipitation and how these interactions affect their atmospheric lifetime and long-range transport to regions such as the Arctic. In collaboration with Rachel Scholes in Environmental Engineering at UBC, we are investigating how tire-wear additives react with atmospheric oxidants (ozone, OH, NO3) and whether these reactions form more toxic products relevant to air quality and health. In collaboration with Nancy Ford in Oral, Biological, and Medical Sciences at UBC, we are characterizing the chemical composition of e-cigarette aerosols and their potential impacts on respiratory and oral health. 

Why It Matters

These emerging pollutants are ubiquitous in the atmosphere and may affect cloud formation, precipitation, transport to pristine environments, and health. Understanding their cloud formation potential, reactivity, and toxicity helps assess their influence on climate, deposition, and human health. 

Key Questions or Goals 

• When and under what conditions do microplastics, tire wear, and brake wear particles nucleate ice? 
• How does ice nucleation affect their transport and deposition, including to Arctic regions? 
• How do atmospheric oxidants modify their chemical and toxic properties? 
• What chemicals are present in e-cigarette aerosols, and how might they affect lung and oral health? 

Approach / Methods 

• Freezing assays to quantify ice-nucleating activity. 
• Oxidation and aging experiments using ozone, OH, and UV light. 
• Chemical identification with high-resolution mass spectrometry. 
• With collaborators, modeling to assess transport and deposition. 

Selected Publications 

• Seifried, T.M., S. Nikkho, A. Morales Murillo, L.J. Andrew, E.R. Grant, and *A.K. Bertram, Microplastic particles contain ice nucleation sites that can be inhibited by atmospheric aging. Environmental Science & Technology, 2024, 58(35): p. 15711-15721.
  
• Bieber, P., T. M. Seifried, W. Bae, A. K. Bertram, and N. Borduas-Dedekind. Contact line ice nucleation is the dominant freezing mechanism for water on macro- and microscopic polypropylene surfaces. Langmuir, 41(46), 31312–31323.

Collaborators / Partners 

• Andreas Stohl, University of Vienna
• Arthur Chan, University of Toronto
• Nadine Borduas-Dedekind, University of British Columbia
• Steve Rogak, University of British Columbia