Thallium may also be used as a component in food packaging materials.
Additional uses of thallium in Canada are in products available to consumers: as a radiopharmaceutical in human drug products and as a medicinal ingredient in homeopathic licensed natural health products. Other uses include use in low temperature thermometers, mercury arc lamps, alloys with other metals, jewellery, fireworks, pigments and dyes, and for mineralogical separation. The main uses of thallium substances include use in semiconductors and the laser industry, fiber (optical) glasses, photoelectric cells, and high temperature superconductors, as activators in gamma radiation detection equipment (scintillometer), and as intermediates in chemical production. Less than 30 kg of thallium were imported into Canada in 2017. There were no other reports of manufacture or imports above the reporting threshold of 100 kg/yr. In 2011, 100 – 1000 kg/yr of thallium chloride (CAS RN ) was manufactured in Canada. Three thallium substances (CAS RN 563-68-8, -59-1) were included in a survey issued pursuant to a CEPA section 71 notice. Thallium production is low with less than 9 tonnes produced globally in 2017. Thallium is present in many natural minerals as well as in meteorites, volcanic rocks, plants, and trace amounts in most living organisms.Īnthropogenic sources of thallium are primarily associated with the incidental production and releases of residues/by-products from various industrial activities, such as smelting/refining processes, metal mining, and fly ashes of coal-fired electrical power plants. It is typically associated with sulfide ores of various metals including zinc, copper, iron, and lead, and is also present in coal. Thallium exists in the earth’s crust at an average concentration of 0.7 mg/kg. The Chemical Abstracts Service Registry Numbers (CAS RN Footnote 1 ), their DSL or R-ICL names and their common names are listed in the table below.Ī This substance was not identified under subsection 73(1) of CEPA but was included in this assessment as it is highly reactive when exposed to moisture in air and releases thallium ions under environmental conditions.ī This substance was not identified under subsection 73(1) of CEPA but was included in this assessment as it was identified for further consideration following prioritization of the Revised In Commerce List (R-ICL). This includes three thallium-containing substances on the Domestic Substances List (DSL) identified as priorities for assessment as they met categorization criteria under subsection 73(1) of CEPA or were considered a priority on the basis of other ecological concerns, and two thallium-containing substances that were identified for further consideration following prioritization of the Revised In Commerce List (R-ICL). This assessment considers all thallium-containing substances, that may release thallium as well as thallium in its elemental form, and thallium released in the environment in dissolved, solid or particulate forms. The scope of this assessment is on the thallium moiety. Pursuant to section 68 and 74 of the Canadian Environmental Protection Act, 1999 (CEPA), the Minister of the Environment and the Minister of Health have conducted a screening assessment of thallium and its compounds. Acute toxicity studies for thallium in freshwater 8.1 Uncertainties in evaluation of risk to human health.7.3.4 Sensitivity of conclusion to key uncertainties.7.3.3 Weight of evidence for determining potential to cause harm to the Canadian environment.7.3.2 Consideration of the lines of evidence.7.3 Characterization of ecological risk.7.2.5 Coal-fired electric power generation plants.7.2.4 Base metal smelting and refining (BMS).7.2.2 Approach for the exposure characterization.7.2.1 Natural background concentrations.7.1.5 Effects on soil-dwelling organisms.
6.3.4 Bioaccumulation in terrestrial animals.6.3.3 Bioaccumulation in terrestrial plants.6.3.2 Bioaccumulation in aquatic organisms.6.1.1 Potential for long-range transport.
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