Base de données de recherche des TNO

Régions: North Slave Region

étiquettes: contaminants, mining, health, arsenic, public health

Objectif(s): To establish a baseline of contaminant exposure and possible health effects in Yellowknife, Ndilo and Dettah, to ensure the Giant Mine Remediation Project (GMRP) does not negatively impact the health of the communities during remediation activities at the mine site.

Description du projet: This licence has been issued for the scientific research application No.5380. The Health Effects Monitoring Program (YKHEMP) begun in 2017 with the main objective to establish a baseline of contaminant exposure and possible health effects in Yellowknife, Ndilo and Dettah, NWT, to ensure the Giant Mine Remediation Project (GMRP) does not negatively impact the health of the communities during remediation activities at the mine site. The study also aimed to answer the question of whether local residents were being exposed to higher levels of arsenic compared to other Canadians. YKHEMP is a long-term monitoring program and as such, will be repeated every five years to follow the trends and investigate the long-term relationships between arsenic in the urine and toenails, and health effects. Baseline levels, for arsenic and other contaminants of potential concern (COPCs) including antimony, cadmium, lead, manganese and vanadium were completed in 2018. Establishing this baseline was very important in making sure accurate monitoring of exposure to arsenic is done in the years to come. The program aims to assess the exposure and health impacts of arsenic and other COPCs on the local human populations as part of the GMRP. The next follow-up sampling period is scheduled to take place in 2023 with children and youth aged 3 to 19, and a follow-up study for all participants, including adults is planned for 2027-2028. Ongoing specific objectives of the program include: a) Continue to collect biological samples of toenail and urine from consenting participants from Yellowknife, Yellowknives Dene First Nation, and North Slave Métis populations to assess current levels of arsenic. b) Analyze collected samples to characterize COPC exposure, particularly arsenic, within the populations and draw comparisons with the 2017-18 baseline levels and other Canadians. c) Investigate any associations between COPC levels, particularly arsenic, within the population and observed or reported health outcomes. d) Explore results sharing with other related studies to understand sources of contaminant exposure and health interactions. e) Continue to archive collected urine and toenail samples for future reference, in a biobank. f) Continue to establish a detailed protocol including a set of benchmarks for the future of the on-going monitoring program. Guiding research questions: 1. Are the internal concentrations of arsenic and other COPCs in Yellowknife, Ndilo and Dettah residents the same or higher when compared to the 2017-18 baseline levels? 2. Is there a significant correlation between measured biomarkers of exposure and concentrations of environmental exposure sources? 3. What health outcomes are associated with the arsenic exposure in the population? The proposed study is of combined cohort and longitudinal design, which means this is a type of research program that follows large groups of people over a long time. Baseline sample collection took place over two years and was completed in 2018 with a total 2037 participants representing three main populations: Yellowknife (YK), Yellowknives Dene First Nation (YKDFN), and North Slave Métis Alliance (NSMA). Participation was both voluntary and through random selection. Participation through random selection was representative of the Yellowknife population and comparable to the rest of Canada. As part of YKHEMP on-going monitoring, the next round of resampling is scheduled to take place in 2023 with children and youth aged 3 to 19 years. CHILD/YOUTH FOLLOW-UP RESAMPLING COMPONENTS to include: (i) Participant sampling (ii) Interview (Includes lifestyle and food frequency questionnaire) (iii) Biological sample collection: urine and toenail clippings (iv) Biological sample collection: saliva (new participants only) (v) Review of medical records (for past 5 years) (i) PARTICIPANT SAMPLING: The sampling strategies used in 2017-18, will be followed as they were developed with extensive consultations with program stakeholders and communities at that time, and were deemed to be the most appropriate for their respective communities: 1) YK population: The initial sampling strategy was developed with the assistance from Statistics Canada to ensure a representative sample size. For the 2023 follow-up resampling, all child and youth participants (aged 3 to 19 at the time of 2017-18 testing), will be invited to participate, by post or an email, even if some of those youths are now adults. To make up for attrition of original participants (i.e. due to moving or other reasons), Statistics Canada will use the Yellowknife address list to select additional households, randomly and proportionally, across the 10 districts. A new child or youth participant will be further randomly selected within the household based on whose birth date is next. In addition to the new randomly selected individuals, the program will also accept volunteer participants, if they approach the study team asking to participate, as the program is inclusive and does not want to turn anyone away that is worried about their exposure. All participants, will receive their results in a personal letter, when ready. However, the results of the volunteer participants will not be included in the sample population of the Yellowknife residents to be representative of Yellowknife as they were not randomly sampled and could introduce sampling bias. 2) YKDFN population: All 2017-18 Yellowknives Dene children and youth participants will be contacted to participate in the follow-up program by a letter delivered in person in Ndilo and Dettah, and new participants will be welcome to participate. Using the same approach during baseline sample collection, new voluntary participants will be checked off from a list of households using maps of Ndilo and Dettah. If a certain demographic is lacking that demographic will be contacted and invited to participate in the study to ensure sufficient representation across both communities. 3) NSMA population: All 2017-18 North Slave Metis children and youth participants will be contacted to participate in the follow-up monitoring by a letter sent directly from NSMA leadership through their internal mail directory, and new participants welcome to participate. Summary Inclusion Criteria: - All child and youth participants aged 3 to 19 at time of testing in 2017-2018 - New participants 3 to 19 (to make up for attrition rate) - Able to provide written informed consent and/or assent - Lived in Yellowknife, Ndilo or Dettah in the previous 12 months (ii) INTERVIEW: Child and youth participants, who provide consent and assent (for those aged 3 to 12), will be asked to complete a Lifestyle and a Food Frequency Questionnaires. The lifestyle questionnaire will contain two components: general information and exposure history (e.g. lifestyle, diet, water, and recreation sources). The Food Frequency Questionnaire (FFQ) will contain questions about wild fish consumption (i.e. types and fishing locations). Information of serving sizes will be collected using food models. The Yellowknives Dene children and youth will also answer additional questions about consumption of other animals, plants, berries and mushrooms as decided by the Yellowknives Dene leadership back in 2017. The interview will conclude by recording the individual's height (using a measuring tape) and weight (using a scale). (iii) BIOLOGICAL SAMPLE COLLECTION: Urine and toenail clippings Research assistants will provide participants with a kit to collect toenail clippings and urine at their own convenience at home, along with instructions to arrange for sample pick up by staff or drop off at the local office. Samples will be kept in a refrigerator at the local office in Yellowknife under appropriate storage conditions until ready for shipping to uOttawa lab for analysis. Samples at uOttawa will be prepared accordingly then undergo speciation analysis via high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). HPLC-ICP-MS will analyze the samples for the different arsenic species in urine. Urine samples will also be analyzed for other COPCs (antimony, cadmium, lead, manganese and vanadium). A strict quality assurance/quality control program including the analysis of blank samples and standard reference materials will be followed. In order to ensure quality of analysis, about 5% of the samples will be measured by another independent laboratory, e.g. the Centre de Toxicologie - INSPQ in Quebec that performs analyses for the Canadian Health Measures Study. Biomarker analysis: A sub-sample of urine samples collected from children and youth will also be analyzed for CC16 and KIM-1 levels via ELISA (Enzyme-Linked Immunosorbent Assay) to assess for lung and kidney function, respectively. (iv) BIOLOGICAL SAMPLE COLLECTION: Saliva samples will be taken with a buccal swab inside a person’s cheek. Only new participants will be asked to provide a buccal swab, as this is something that only needs to be provided once in the study by an ongoing participant. Samples will be kept in a refrigerator at 4ºC at the local office in Yellowknife under appropriate storage conditions until ready for shipping to Génome Quebec lab in Montreal, for analysis. At the laboratory, the saliva sample will be sequenced only for selected polymorphisms and genes related to arsenic to see whether an individual has or does not have 20 specific genes that can help them to get rid of arsenic in their body more easily. (v) REVIEW OF MEDICAL RECORDS: A part-time Medical Researcher will access medical records for the past 5 years of those individuals who will provide consent. Medical record data will only be used to investigate possible associations between contaminant exposure and specific health outcomes at the population level. No medical files will be removed from the office. The researcher will go over the files and compile information into a password protected database. As part of YKHEMP’s ongoing communication, the team plans to organize Community Results Workshops in November 2022 with all three communities to share all results from the 2017-2018 baseline sample collection that are now available (i.e. results from genetics, toenail and medical files that took time to analyze and are only now available). Presentations and pamphlets of summary results will be developed for each population by October 2022 to share at the workshops. As the program approaches Spring 2023, the team will be gearing up for the 5-year follow-up of children and youth resampling in Yellowknife, Ndilo and Dettah. Letters of invitation will be sent out to all 2017-2018 participants who were 3 to 19 years of age at that time even if some of them are older now. Local research staff will be hired and trained, and there will be extensive communications via radio and social media to inform the public about the upcoming study. Community meetings will also be planned with the general Yellowknife population, the Yellowknives Dene First Nation and the North Slave Métis Alliance to present the follow-up results and provide opportunities for questions, approximately one year after resampling is complete. In addition, the overall results from all participants will be compared to the 2017-18 YKHEMP baseline sample results and to the data of the Canadian population from the Canadian Health Measures Survey, and final results presented in a report that will be shared publicly. Any public messages will be devised, with approval from the Government of Northwest Territories Health Authority and other stakeholders, to ensure the public is made aware of any pertinent findings. Various media outlets will be used including radio, newsletters, website, and social media to share overall findings with the affected communities. Academic papers will be written using results at the population level only, and feedback sought from all Health Effects Monitoring Program Advisory Committee stakeholders, before any papers are published and shared with the wider community. The fieldwork for this study will be conducted from January 1, 2023 to December 31, 2023.