Hudson Bay Mining and Smelting Co., Limited (HBMS) has operated a fully-functional mine and base metal smelting complex in Flin Flon, Manitoba, since the 1930’s. Mining and smelting activities have gradually led to a build-up of naturally occurring metals in the environment in the Flin Flon area • Historical releases related to wind blown materials (fugitive dusts from tailings; storage piles) into residential communities or ecological areas of interest; • Atmospheric emissions from historical and/or on-going stack emissions from smelting facilities; • Historical materials use off site (in community or residential areas)
The ‘Flin Flon area’ includes Flin Flon and Channing, Manitoba, and, Flin Flon and Creighton, Saskatchewan
• 2007 Manitoba Conservation report; “Concentrations of Metals and Other Elements in Surface Soils of Flin Flon, Manitoba and Creighton, Saskatchewan, 2006” • Levels of some metals were elevated in soil but there was no immediate risk to human health • The report recommended further study to better understand potential health risks for people living in the Flin Flon area related to the HBMS smelter emissions • The Flin Flon Soils Study was the result of this recommendation.
Community Community Advisory Committee Independent Expert Review Panel Technical Advisory Scientific Peer Committee Review HBMS Ethics Review Study Team Intrinsik Goss Gilroy Habitat
• Manitoba Conservation • Manitoba Health • Manitoba Innovation, Energy and Mines (IEM) • Saskatchewan Ministry of Environment • Saskatchewan Ministry of Health • Health Canada • Representatives from the Community Advisory Committee (consists interested members of the public, including representatives of local organizations)
Technical Oversight/Government Interaction Establishment of Process Development of TOR Community Interaction Collection and QAQC and Study Protocol Supplemental Data HHRA/ERA Weight of Evidence Evaluation DRAFT REPORT External Review FINAL REPORT
• RA is one of the tools in the “tool box” • RA will inform the need for other tools, and will provide direction • Weight of evidence tools: • Bioaccessibility • Evaluation of Exposure (biomonitoring) • Medical Surveillance (community health status)
• Human health risk assessment is a scientific process that is used to estimate the likelihood that a population may experience adverse health effects as a result from exposure to particular chemicals in the environment. • It considers the following factors: – How dangerous a chemical is known to be; – How sensitive people are to the chemical; – How a person might come into contact with the chemical such as swallowing, breathing, or skin contact as well how often and how long they are exposed; and, – How much of the chemical a person is exposed to.
Summary of HHRA Results for Non-Cancer Endpoints (Toddler) East Flin West Flin Typical Chemical Creighton Channing Flon Flon Background Arsenic Cadmium Copper Lead Inorganic mercury Methyl mercury Selenium Summary of HHRA Results for Carcinogenic Endpoints (Lifetime Receptor) Chemical East Flin Flon West Flin Flon Creighton Channing Arsenic Cadmium Negligible risk – no further investigation required Potential risk – risk management or further consideration such as an Exposure Study of residents may be required
• An HHRA may indicate that further information is required to understand exposure and potential human health risks • A direct way to obtain additional information on human health risks is to assess human exposure through biological samples ( e.g . blood, urine) • Biomonitoring or an evaluation of environmental contaminant exposure can be undertaken to assist in supplementing the information in the HHRA
• An evaluation of exposure examines the levels of internal exposure to selected chemicals that a person or group of people encounter • Sometimes referred to as biomonitoring, these studies focus on quantifying and determining exposures and effects in humans through the use of biomarkers – Biomarkers for measuring exposure are generally measurements of chemicals or chemical components that are found in people’s fluids or tissues ( e.g . lead in blood, arsenic in urine, etc.) • Evaluations of exposure provide information on actual exposures received by people and account for exposures from all potential sources, pathways and routes that a person encounters
• What is the current level of internal exposure to chemicals of concern in the population residing in the affected area? • Do residents have higher levels of exposure than residents living in areas without a point source of contamination? • Based upon the current scientific literature, what are the health risks from the levels of chemicals of concern in blood or urine found in people in the affected area? • What personal factors are associated with the level of measured internal exposure of people in the affected area (e.g., place of residence, place of work, level of chemicals in soil, age, gender, diet, personal habits, etc.)?
• Children, in general, are more sensitive to exposure to environmental contaminants than adults. • Children eat more food, drink more water, and breathe more air relative to their size than adults do. So they may be exposed to relatively higher amounts of contaminants in these media. • Behavior and habits are also a factor. Children’s normal activities, such as putting hands in their mouths or playing on the ground, create additional opportunities for exposures to environmental contaminants that adults do not face. • Environmental contaminants may affect children disproportionately because their immune defenses are not fully developed or their growing organs are more easily harmed. • In short, if the average exposure levels in children are not elevated, it would be unlikely for other age groups to have elevated levels from just living in an exposed community (and not through their occupation).
• Preliminary info from the HHRA for the Flin Flon area indicated that further information would assist to fully understand exposure to potential human health risks associated with some metals in the community • Through September and October 2009 the study team conducted interviews with 251 households • Data was collected from 447 individuals • 377 urine samples, 202 blood samples • Urine was analyzed for arsenic (inorganic, and total) and inorganic mercury • Blood was analyzed for lead
Arsenic –soil (ug/g) 100 90 80 70 60 50 Arsenic 40 30 20 10 0 East Flin Flon West Flin Flon Channing Creighton
Results of the Urinary Arsenic Evaluation • Urinary arsenic levels in Flin Flon are comparable to levels in other communities (smelter and control) • In general, total and inorganic urinary arsenic levels found in children in the Flin Flon area were not high enough to be associated with increased health risks; a few children were referred for individual follow-up • No real pattern relating elevated soil levels and elevated exposures
Mercury – soil (ug/g) 140 120 100 80 60 Mercury 40 20 0 East Flin Flon West Flin Flon Channing Creighton
Results of the Urinary Inorganic Mercury Evaluation • Urinary mercury (inorganic) levels in Flin Flon are less than in other communities • Majority of samples collected from Flin Flon had no detectable levels of inorganic mercury • Detectable levels were not high enough to be associated with health risks • No real geographic pattern of elevated exposure
Lead - soil (ug/g) 400 350 300 250 200 Lead 150 100 50 0 East Flin Flon West Flin Flon Channing Creighton
Results of the Blood Lead Evaluation • Exposure study suggest that lead levels are slightly higher than levels from national studies of similar age groups, and are similar to levels found in children in other atypically exposed Canadian communities • Community averages are less than the current benchmarks; however, benchmarks are trending lower and 13% exceed study benchmark (5 ug/dL) • Several factors were identified as being potentially associated to blood lead levels, including: – Child’s sex (males higher BLL than females) – Region of residence – Adult use of tobacco (number of current smokers in the house increases BLL) – Age of the house (potential indicator of lead paint) – Types of pipes
• Arsenic and Mercury – No indication of elevated exposures – No further action warranted • Lead – Slightly elevated lead exposures were noted in West Flin Flon; to a lesser extent in Creighton and East Flin Flon – Source of lead is unclear; potential sources include • Soil • Plumbing • Historic use of lead paint • Lead-contaminated toys and consumer products • Hobby items – Based on the outcome of the HHRA and exposure studies, recommendations have been made to address lead in the environment
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