Trainee Spotlight: Hélène Angot

By Bevin P. Engelward

MIT Superfund Program Director

Dr. Hélène Angot is a postdoctoral associate at MIT in Professor Noelle Selin’s group. She investigates the atmospheric sources and fate of toxic global pollutants through observational and modeling tools. Toxic pollutants are emitted into air worldwide by multiple natural and anthropogenic sources. The atmosphere provides both a route of exposure (via inhalation) and a means for the long-range transport and transformation (e.g., oxidation) of pollutants in the environment. Through a modeling approach, Dr. Angot aims to draw the link between global emissions and local impact on Maine tribal areas.

Currently, Dr. Angot contributes to Project 2 of the MIT Superfund Research Program, aimed at modeling the atmospheric transport and fate of carcinogenic polycyclic aromatic hydrocarbons (PAHs) and their degradation products (oxy- and nitro-PAHs). These compounds are present in Superfund and other contaminated sites, such as the Loring Air Force Base near Limestone, ME, making an understanding of their lifecycle especially relevant to the MIT SRP Center. While degradation products can be more toxic and harmful than their primary precursors, their atmospheric reactivity and fate is poorly understood. A fully coupled scheme is currently under development within the global chemical transport model GEOS-Chem. The ultimate outputs are model estimates of PAHs and degradation products’ atmospheric levels, which are crucial for improving estimates of potential exposures and public health impact. This work is done in close collaboration with Prof. Mathew Evans’ group at the University of York’s Chemistry Department (UK) and Prof. Jesse Kroll’s group at MIT.

In addition to PAHs, Dr. Angot also studies atmospheric mercury (Hg) transport and transformation. Upon deposition to ecosystems, Hg converts to highly toxic methylmercury (MeHg) and bioaccumulates in aquatic systems. Tribal communities are therefore particularly affected by Hg contamination due to their traditional dependence on subsistence fishing. The United Nations Minamata Convention on Hg entered into force last summer. Under this Convention and as a co-benefit on greenhouse gases mitigation policies, global Hg emissions are expected to decrease. Dr. Angot is investigating benefits attributable to this policy in terms of future local Hg deposition and fish contamination. In a scenario of delayed global action, benefits will decrease due to increasing legacy emissions (i.e., recycling of previously deposited Hg). These results underline the importance of near-term action for limiting the Hg burden of future generations.