Characterization of mineral dust in high latitudes during cryodesiccation phases and environmental impacts

The contaminants contained in atmospheric dust have the greatest potential in terms of rapid transport and long-distance travel. However, few studies to understand how dust emitted at high latitudes may have consequences on a global scale. Mining sites are one of the sources of atmospheric dust emissions. It has been shown that dust originating from mine tailings is rich in metals such as arsenic, lead, and cadmium. The concentrations of these metals are high enough to contribute to the contamination of surrounding environments, creating a real risk for wildlife, vegetation, and public health.

This project focuses on the characterization of dust originating from the tailings storage facility of the Éléonore gold mine located in the James Bay in Québec (Canada). Due to its high-latitude location, the site is subject to the phenomenon of cryodesiccation. The cryodesiccation period is identified as one of the most significant phases for dust emissions. It is during these periods that the physicochemical properties of emitted atmospheric dust are studied. We focus on particle size distribution through active measurements (e.g., optical particle counters, minivol samplers, PurpleAir) and passive measurements (e.g., dust jars, MWAC samplers). Particle size from mine tailings is an important characteristic because it affects atmospheric transport and because fine particles do not have the same public health impacts as coarser particles. The quantification of particle emissions (PM10, PM2.5) will be correlated with meteorological data in order to better understand the influence of meteorological conditions on emissions. Dust emission simulations were conducted using a portable in situ wind erosion laboratory (PI-SWERL). The aim is to estimate dust emissions generated during dust storms and to compare them with measurements obtained from our instruments. For the purpose of identifying the different metals contained within mineral dust, dust samples are collected on filters and analyzed by ICP-MS.