Environmental contaminants: Sources and fate by innovative multi-proxy isotope approaches

点击翻译按钮获取中文摘要

Contaminants are today a major societal issue for most countries, their presence often exceeding national and international quality guidelines. As a result, interest in monitoring networks of environmental quality have grown substantially in the past several years. Still, there is a knowledge gap about the eventual transformation of these contaminants in the environment, arising the need to develop and implement innovative approaches to better constrain the sources and processes controlling their budgets, with the ultimate objective of designing specifically targeted management plans where needed. In this Discovery Grant research program, I am proposing to investigate the cycle of contaminants in the air/-soil/-water continuum through the lens of innovative multi-proxy multi-isotope approaches. I am capitalising on the unique analytical capacities acquired by my research group within the last few years as well as on a privileged access to the facilities of the Geotop research center (a geoscience interuniversity research center aiming at studying Earth dynamics) at UQAM. I will focus throughout the 5 years of this research program on exploring the fate of contaminants once released in the environment, focusing on 2 short-term objectives related to two distinct classes of carbon contaminants: 1) Are photooxidation and ozonation contributing to the presence of aminomethylphosphonic acid (AMPA) in the environment? AMPA, an agricultural and urban degradation byproduct, has been classified as persistent in soils and recent studies have demonstrated its adverse impact on environmental and health qualities. I will particularly focus on the mechanisms responsible for the formation of AMPA by the transformation of either glyphosate-based herbicides (GBH) or of phosphonates present in our sewage effluents. 2) Fingerprinting the contribution of atmospheric Dissolved Black Carbon (DBC), in search of the potential "missing link" in the global carbon budget. Although rivers have been thought to be the main sources of DBC in the oceans, a recent study contradicted this conclusion. Here I will explore the significance of atmospheric deposition as the missing source of DBC. The findings would postulate that direct deposition of DBC through this pathway is also plausible for the cryospheric regions where, so far, black carbon (BC) aerosols solubilized over time are believed to be the only source of DBC prevalent in the region. This research program is highly relevant in the current context of an increasing abundance of environmental contaminants worldwide and will advance our understanding of their sources and fates. Finally, it will offer a stimulating environment for the numerous gender-balanced highly qualified personnel (HQP) who will be involved in the program (4 BSc, 3 MSc and 2 PhD), combining training on state-of-the-art analytical instrumentations with the broad understanding of complex and strategic environmental issues.