Understanding arsenic mobility and speciation in lake sediments impacted by ore roasting near Giant mine, NWT

The roasting of gold-bearing arsenopyrite at Giant mine (Northwest Territories) between 1949 and 1999 released approximately 20,000 tonnes of toxic arsenic-bearing aerosols in the local aerial environment. Detailed examination of lake sediments, sediment porewaters, surface waters and lake hydrology sampled from three lakes of differing limnological characteristics was conducted in summer and winter conditions. Samples were analyzed for solid and dissolved elemental concentrations, speciation and mineralogy. The three lakes are located less than 5km from the mine roaster, and downwind, based on predominant wind direction. The objective of the study was to assess the controls on the mobility and fate of arsenic in these roaster-impacted subarctic lacustrine environments. Results show that the occurrence of arsenic trioxide in lake sediments coincides with the regional onset of industrial activities. The bulk of arsenic in sediments is contained in the form of secondary sulphide precipitates, with iron oxides hosting a minimal amount of arsenic near the surface-water interface. The presence of geogenic arsenic is likely contained as dilute impurities in common rock-forming minerals, and is not believed to be a significant source of arsenic to sediments, porewaters or lake waters. Furthermore, the well correlated depth-profiles of arsenic, antimony and gold in sediments may help reveal roaster impact. The soluble arsenic trioxide particles contained in sediments act as the primary source of arsenic into porewaters. Dissolved arsenic in reducing porewaters both precipitate as secondary sulphides in situ, and diffuse upwards into the overlying lake waters. Arsenic diffusion out of porewaters, combined with watercourse-driven residence time, are estimated to be the predominant mechanisms controlling arsenic concentrations in overlying lake waters. The sequestration of arsenic from porewaters as sulphide precipitates, in the study lakes, is not an effective process in keeping lake-water arsenic concentrations below guidelines for the protection of the freshwater environment and drinking water. Seasonal impacts on lake geochemistry derive from ice covering lake waters, cutting them off from of atmospheric oxygen, along with the exclusion of solutes from the ice. Such effects are limited in deep lakes but are can be an important factor controlling arsenic precipitation and mobility in ponds.

Calling for resistance: The political economy of Indian and Canadian call centre industries

Call centres have in the last three decades come to define the interaction between corporations, governments, and other institutions and their respective customers, citizens, and members. From telemarketing to tele-health services, to credit card assistance, and even emergency response systems, call centres function as a nexus mediating technologically enabled labour practices with the commodification of services. Because of the ubiquitous nature of the call centre in post-industrial capitalism, the banality of these interactions often overshadows the nature of work and labour in this now-global sector. Advances in telecommunication technologies and the globalization of management practices designed to oversee and maintain standardized labour processes have made call centre work an international phenomenon. Simultaneously, these developments have dislocated assumptions about the geographic and spatial seat of work in what is defined here as the new international division of knowledge labour. The offshoring and outsourcing of call centre employment, part of the larger information technology and information technology enabled services sectors, has become a growing practice amongst governments and corporations in their attempts at controlling costs. Leading offshore destinations for call centre work, such as Canada and India, emerged as prominent locations for call centre work for these reasons. While incredible advances in technology have permitted the use of distant and “offshore” labour forces, the grander reshaping of an international political economy of communications has allowed for the acceleration of these processes. New and established labour unions have responded to these changes in the global regimes of work by seeking to organize call centre workers. These efforts have been assisted by a range of forces, not least of which is the condition of work itself, but also attempts by global union federations to build a bridge between international unionism and local organizing campaigns in the Global South and Global North. Through an examination of trade union interventions in the call centre industries located in Canada and India, this dissertation contributes to research on post-industrial employment by using political economy as a juncture between development studies, critical communications, and labour studies.