Chemicals In Canada Research Articles

Towards better control of chemical risks associated with mining operations in Quebec (Canada) Part 1: Repertory of chemicals used in mining

Abstract As of 2020, the mining industry in the province of Quebec (Canada) has been providing 16,000 jobs, the majority of these in the north part of the province and in the Abitibi-Témiscamingue region. From the exploration phase to the mining site rehabilitation phase, numerous chemical processes are used, often involving some of the most dangerous substances used on industrial scales. The hazards associated with many of these substances are in some cases not obvious, and symptoms of exposure may take years to appear. The risks associated with the industrial use of chemicals in Canada and abroad has long preoccupied health authorities, given the severity of the diseases that can occur. In Quebec, occupational diseases associated with exposure to industrial chemicals are reaching 1,500 cases per year. The principal focus of this study, presented in two articles, is to set a preliminary theoretical framework for categorizing chemicals in terms of their effects on the health of workers throughout the various phases of mining projects. The objective is to decrease (over the long term) the number of occupational diseases due to the use of chemicals by raising awareness among employers and exposed workers in the mining sector. This research was conducted in four phases. The present article contains the results of the first two stages, that is, a review of the literature to catalog the industrial chemicals used in mines and to list the potential effects of exposure to them, based on Safety Data Sheets. Eighty-five (85) chemicals used in at least one mining project phase and dozens of potential effects on worker health were identified. The rest of the study is presented in a second article [1]

Agronomics of high density tobacco (Nicotiana tabacum) production for protein and chemicals in Canada

Twenty eight tobacco (Nicotiana tabacum) cultivars were grown under a high density, multi-cropped production system, to determine the impact of stand density and supplemental nitrogen on biomass yields and protein, lutein and solanesol concentrations. At 75,000 plants ha−1, total biomass yields ranged from 5.69 to 8.02 dry t ha−1. In the first growing season, yield was marginally influenced by supplemental nitrogen up to 160 kg ha−1, but increasing stand density from 40,000 to 125, 000 plants ha−1 increased yield significantly. Protein yields did not vary statistically between cultivars, but did respond positively to increasing nitrogen. Both lutein and solanesol levels varied between cultivars and increased as supplemental nitrogen increased. The results support the viability of using tobacco as a source of protein, small molecules and biomass. Additional research on large scale processing and extraction of valuable compounds from tobacco is required to further develop this production system.

Exposure to Endocrine Disrupting Chemicals in Canada: Population-Based Estimates of Disease Burden and Economic Costs

Exposure to endocrine-disrupting chemicals (EDCs) contributes to substantial disease burden worldwide. We aim to quantify the disease burden and costs of EDC exposure in Canada and to compare these results with previously published findings in the European Union (EU) and United States (US). EDC biomonitoring data from the Canadian Health Measures Survey (2007–2011) was applied to 15 exposure–response relationships, and population and cost estimates were based on the 2010 general Canadian population. EDC exposure in Canada (CAD 24.6 billion) resulted in substantially lower costs than the US (USD 340 billion) and EU (USD 217 billion). Nonetheless, our findings suggest that EDC exposure contributes to substantial and costly disease burden in Canada, amounting to 1.25% of the annual Canadian gross domestic product. As in the US, exposure to polybrominated diphenyl ethers was the greatest contributor of costs (8.8 billion for 374,395 lost IQ points and 2.6 billion for 1610 cases of intellectual disability). In the EU, organophosphate pesticides were the largest contributor to costs (USD 121 billion). While the burden of EDC exposure is greater in the US and EU, there remains a similar need for stronger EDC regulatory action in Canada beyond the current framework of the Canadian Environmental Protection Act of 1999.

Review of the state of the art of human biomonitoring for chemical substances and its application to human exposure assessment for food safety

Review of the state of the art of human biomonitoring for chemical substances and its application to human exposure assessment for food safety

Relationship between biodegradation and sorption of phthalate esters and their metabolites in natural sediments

Regulatory evaluations of commercial chemicals in Canada, the United States, the European Union, and other countries aim to identify biodegradation rates of chemicals in natural soils and sediments. However, commonly used biodegradation testing methods are limited in their capacity to determine biodegradation rates under natural environmental conditions. As a result, widely varying biodegradation rates have been reported for many very hydrophobic substances. This variability causes difficulties in regulatory evaluations, potentially leading to chemical misclassification. In the present study, the authors developed a model of the relationship between biodegradation, sorption, and hydrophobicity, and tested the model in experiments that measured the biodegradation rates of a range of di-phthalate esters (DPEs) and mono-phthalate esters (MPEs) in natural sediments. The results indicate that DPEs and MPEs have the inherent capacity to be quickly degraded by microbes in sediments at a common rate, but that DPE biodegradation rates in natural sediments decrease with increasing phthalate ester sorption to sediments. The results show that inherently biodegradable substances that are subject to a high degree of sorption can be expected to exhibit long half-lives in natural sediments. The model provides a potential methodology for assessing biodegradation rates in natural sediments from inherent biodegradation rates measured in screening tests by accounting for chemical sorption. The present study indicates that a reduced rate of biodegradation is due to a reduced fraction of freely dissolved chemical concentration in the interstitial water, and that the environmental significance of sorption-reduced biodegradation rates needs to be viewed in the context of risk in chemical evaluations.

Secrecy is Toxic—Building Community Right-to-Know in Canada's Largest Municipality

The regulation of toxic chemicals in Canada has undergone many twists and turns in the last 40 years. This paper describes the emergence of a new alliance, one which brought together people from a broad range of backgrounds to formulate common strategy to address the continuing use and dissemination of toxic chemicals, especially carcinogens. In just over a decade, Canada's largest municipality, Toronto, adopted a bylaw which introduced a comprehensive scheme for community right-to-know about toxic chemicals being used, released, and disposed-the first in the country. The bylaw represents the success of a network that integrated experience and expertise from community activism, environment, labour, public health, politics and cancer prevention.

Human biomonitoring of environmental chemicals in Canada—Overview of recent activities

Human biomonitoring of environmental chemicals in Canada—Overview of recent activities

Tools for the prioritization of substances on the Domestic Substances List in Canada on the basis of hazard

A precedent setting legislative mandate under the Canadian Environmental Protection Act 1999 to establish priorities for assessment based on systematic consideration of all of the approximately 23,000 Existing Chemicals in Canada required the development and refinement of methodology in a number of important areas. This included development of simple and complex exposure and hazard tools for priority setting which draw maximally and efficiently on available data to systematically identify substances that are highest priorities in relation to their potential to cause adverse effects on the general population. The hierarchical approach in the simple and complex hazard tools described here efficiently and effectively sets substances aside as non-priorities, or prioritizes them for consideration additionally in assessment. The hazard tools efficiently incorporate previous work, contributing to consistency internationally, and involve hierarchical consideration of sources of information based on their relative weighting. They are health protective, based on their incorporated degree of conservatism, and provide direction for additional assessment for substances deemed to be priorities. Although designed for prioritization of Existing Substances in Canada, these tools have potential for broader application in other national and international programs to provide focus and increase efficiency in human health risk assessment.

Testing Toxicity: Proof and Precaution in Canada's Chemicals Management Plan

This article explores questions of proof and precaution in the context of Canada's new Chemicals Management Plan. That plan includes a bold initiative known as the ‘Challenge’, under which the government has identified 200 high priority chemicals for which it is ‘predisposed’ to a finding of toxicity. The presumption will operate unless the challenged stakeholders submit ‘information’ sufficient to rebut it. Through comparison with the European REACH regulation, this article explores exactly what burdens have been shifted, to whom and why. It also evaluates the significance of this move for the governance of chemicals in Canada and for the health of Canadians. It looks specifically at the case of Bisphenol A, which was one of the 200 chemicals included in the Challenge, and was recently declared toxic under that process. The Challenge forces us to confront the ‘dilemma of industry data’, which complicates the debate over a shifted burden of proof in the context of chemicals management.

Quantitative Structure Activity Relationships for Predicting the Bioaccumulation of POPs in Terrestrial Food‐Webs

AbstractKOW based QSARs are used to assess the bioaccumulation potential of thousands of commercial chemicals in Canada and internationally. The QSARs, which are based on information from aquatic organisms, identify chemicals with a log KOW>5 to have a potential to biomagnify in food‐chains. This study investigates whether KOW based QSARs are also effective in identifying biomagnifying chemicals in terrestrial food‐chains. First, a terrestrial bioaccumulation model is developed and used to hypothesize the general relationship between the chemical's octanol‐air and octanol‐water partition and its biomagnification potential. Secondly, field observations of the bioaccumulation of persistent organic pollutants in wolves are used to test the hypothesis and explore the fundamental differences between QSARs for bioaccumulation in aquatic and terrestrial food‐chains. The results indicate that (i) QSARs for bioaccumulation in terrestrial food‐chains should include both octanol‐air (KOA) and octanol water partition coefficients (KOW); (ii) chemicals with a log KOA>approximately 5 can biomagnify in terrestrial food‐chains if log KOW>2 and the rate chemical transformation or metabolism is low; (iii) biomagnification factors in terrestrial food‐chains are much greater than those in aquatic food‐chains; (iv) biomagnification factors of very hydrophobic substances (log KOW>7) in terrestrial biota do not drop off with increasing KOW as has been observed in aquatic biota. The relevance of these findings is that current regulations and protocols may misidentify (i) low KOW but high KOA chemicals as having no bioaccumulation potential and (ii) very hydrophobic (log KOW>8.5) which appear not to biomagnify in aquatic organisms but have the potential to biomagnify in terrestrial food‐chains. Considering that 67.9% of the approximately 12 000 organic chemicals on Canada's Domestic Substances List exhibit high KOA but low KOW, this represents a major gap in our methods for screening bioaccumulative substances.

Renal cell carcinoma and occupational exposure to chemicals in Canada.

This study assesses the effect of occupational exposure to specific chemicals on the risk of renal cell carcinoma in Canada. Mailed questionnaires were used to obtain data on 1279 (691 male and 588 female) newly diagnosed, histologically confirmed renal cell carcinoma cases and 5370 population controls in eight Canadian provinces, between 1994 and 1997. Data were collected on socio-economic status, smoking habit, alcohol use, diet, residential and occupational histories, and years of exposure to any of 17 chemicals. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived using unconditional logistic regression. The study found an increased risk of renal cell carcinoma in males only, which was associated with occupational exposure to benzene; benzidine; coal tar, soot, pitch, creosote or asphalt; herbicides; mineral, cutting or lubricating oil; mustard gas; pesticides; and vinyl chloride. Compared with no exposure to the specific chemical, the adjusted ORs were 1.8 (95% CI = 1.2-2.6), 2.1 (1.3-3.6), 1.4 (1.1-1.8), 1.6 (1.3-2.0), 1.3 (1.1-1.7), 4.6 (1.7-12.5), 1.8 (1.4-2.3) and 2.0 (1.2-3.3), respectively; an elevated risk was also associated with exposure to cadmium salts and isopropyl oil. The risk of renal cell carcinoma increased with duration of exposure to benzene, benzidine, cadmium, herbicides and vinyl chloride. Very few females were exposed to specific chemicals in this study; further research is needed to clarify the association between occupational exposure to chemicals and renal cell carcinoma in females.

A regionally segmented national scale multimedia contaminant fate model for Canada with GIS data input and display

Regional scale mass balance models are valuable tools for describing the fate of chemicals in areas with defined and fairly homogeneous environmental characteristics and chemical use patterns. These models often show that contaminant inflows from outside the region of interest are significant compared with local emissions. This is most likely for persistent chemicals and those that are efficiently transported in air or water. As a result regional levels of environmental contamination are controlled by external factors and meaningful evaluation requires assessment of contaminant fate in neighboring regions. A linked set of regional models thus has the potential to describe quantitatively the impact of chemical emissions over a wider geographic scale with significant spatial differences in environmental characteristics and chemical use patterns. We describe here a national scale contaminant fate model for Canada based on the existing 24-region ChemCAN model. The ecological regions, which were previously treated individually, are linked with flows of air and water deduced from GIS analysis to provide a comprehensive description of contaminant fate over the entire country, including long-range transport between regions. The model is applied to describe the national-scale fate of three chemicals in Canada, benzene, trichloroethene, and diethylhexyl phthalate, exploiting GIS analysis for interpretation and presentation of model results. Agreement between predicted multimedia environmental concentrations and measured values is satisfactory for all three chemicals. In total this work represents an initial attempt to address the different processes of both linking a regional model and using GIS as a tool for data analysis and management.

Endocrine Disrupting Substances and Ecological Risk Assessment of Commercial Chemicals in Canada

Abstract The ecological risk assessment of commercial chemicals in Canada by the regulatory programs of the Commercial Chemicals Evaluation Branch, Environment Canada, are based on results from traditional toxicity data (e.g., lethality, effects to growth or reproduction). Some of the chemicals under consideration are known to alter endocrine systems in exposed organisms; however, effects to the endocrine system are used only as additional supporting information. Presently, there are no internationally accepted methodologies or tests for endocrine disrupting substances that can be used by these regulatory programs. The need for research with respect to hormone disrupting substances has been recognized in the revised Canadian Environmental Protection Act, 1999 (CEPA 1999). This paper describes the framework for the ecological risk assessment of new and existing substances and identifies issues and research needs in both screening level and in-depth ecological risk assessments with respect to the identification and assessment of potentially endocrine disrupting substances.

Non-Hodgkin's lymphoma and occupational exposure to chemicals in Canada

Summary Background: The incidence of non-Hodgkin's lymphoma (NHL) has been increasing in Canada. This study assessed the effect of occupational exposure to specific chemicals on the risk of NHL. Patients and methods: Mailed questionnaires were used to obtain data on 1469 newly diagnosed, histologically confirmed NHL cases and 5073 population controls between 1994 and 1997 in eight Canadian provinces. Data was collected on socioeconomic status, life-style, diet, occupation, and years of exposure to any of 17 chemicals. Odds ratios (OR) and 95% confidence intervals (95% CI) were derived by logistic regression. Results: The study found an increased risk of NHL among males exposed to benzidine, mineral, cutting, or lubricating oil, pesticides, and herbicides. Compared with non-exposure to each specific chemical, the adjusted ORs were 1.9 (95% CI: 1.1–3.4) for benzidine, 1.3 (95% CI: 1.0–1.5) for mineral, cutting, or lubricating oil, 1.3 (95% CI: 1.0–1.6) for herbicides, and 1.3 (95% CI: 1.0–1.6) for pesticides. Excess risk of NHL among females was associated with exposure to pesticides and wood dust. ORs increased with increasing exposure in years to benzidine and herbicides for males and with increasing exposure years to wood dust for females. These trends were statistically significant (P Conclusions: The findings in this study suggest that occupational exposure to specific chemicals plays an important role in the development of NHL in Canada.

Standard setting and protection of human health and safety.

Human health and safety are determined by the behavior and performance of the individual, or of a piece of equipment, under the prevailing conditions. Setting health or safety standards, which will define a set of conditions to provide protection, requires consideration of many factors, including the level of protection required and the collection and assessment of factual information. The purpose of the paper is to identify and discuss the elements of the standard-setting process and the major issues likely to be associated with it. Occupational exposure values and other initiatives to provide protection of human health from the potential effects of chemicals in Canada are reviewed in the context of recent initiatives and current pressures for change.

Control of Toxic Chemicals in Canada: An Analysis of Law and Policy

Control of Toxic Chemicals in Canada: An Analysis of Law and Policy

Fine chemicals in Canada

Journal of the Society of Chemical IndustryVolume 46, Issue 17 p. 382-383 Article Fine chemicals in Canada T. H. Wardleworth, T. H. WardleworthSearch for more papers by this author T. H. Wardleworth, T. H. WardleworthSearch for more papers by this author First published: 29 April 1927 https://doi.org/10.1002/jctb.5000461707AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume46, Issue1729 April 1927Pages 382-383 RelatedInformation