What were the findings of the Flin Flon Soil Study?
Community Health Status Assessment
The Community Health Status Assessment was completed by public health officials from Saskatchewan and Manitoba. It indicated that the overall health status of the Flin Flon area population is as good as, if not better than, the provincial averages for most health outcomes studied. Cancer incidence rates for men and women were not significantly elevated in the Flin Flon area.
Human Health Risk Assessment & Evaluation of Exposure
Overall, the conclusion of the Human Health Risk Assessment and Exposure Level studies was that the likelihood of adverse health effects among Flin Flon area residents from exposure to the metals evaluated was negligible to low. These findings are reassuring but certain low level risks were identified from some metals, so reducing air emissions, continued monitoring and additional precautionary measures were recommended.
The Human Health Risk Assessment predicted people’s exposure to smelter-related chemicals in the communities of Flin Flon and Creighton area. Early results of the Human Health Risk Assessment indicated there is some potential for elevated exposure to lead, inorganic mercury and arsenic.
To provide a better understanding of people’s exposure levels, an Evaluation of Exposure was conducted in 2009 to measure the actual exposure of children to these three metals by collecting and analyzing blood and urine samples. This study focused on children because of their increased sensitivities to metals and their increased likelihood of exposure.
After evaluating 202 blood samples for lead and 379 urine samples for inorganic mercury and arsenic, researchers responsible for the 2009 Evaluation of Exposure study concluded that:
- Levels of inorganic mercury and arsenic were not elevated in the urine of children. The urinary arsenic levels found in Flin Flon area were very similar to those found in other Canadian communities.
- Measured blood lead levels in children from Flin Flon did not indicate immediate health concerns; the measured levels were comparable with or even slightly lower than other Canadian smelter communities, and were slightly higher than the average levels reported for a large US national study.
- Many factors were associated with the measured blood lead levels in children from the Flin Flon area including gender, area of residence and the year that the house was constructed; age of house may indicate other sources of exposure like lead paint or pipes.
A few children (2%) had measured blood lead levels which were above the Canadian Blood Lead Intervention Level; this is the level at which action is recommended to reduce exposure. As a precaution, for the Flin Flon Soil Study, a more sensitive reference point than the Canadian Blood Lead Intervention was used; as a result about 13% of the children tested were referred to a physician for follow-up.
What were the findings of the follow-up Exposure Evaluation conducted in 2012?
A follow-up Exposure Study was recommended to measure how the blood lead levels of children living in Flin Flon were affected by the exposure reduction strategies implemented and by the closure of the Hudbay smelter in June 2010.
The 2012 Exposure Evaluation study took an almost identical approach to the 2009 study. The one change was that environmental samples were also collected (e.g., household dust, yard soil, tap water and paint assessments) for the households where children who were providing blood samples lived. In total, blood samples were collected from 118 children under 7 years of age living the Flin Flon area.
Comparison of the results from the 2009 and 2012 studies indicated blood lead levels in children decreased significantly following the closure of the smelter in June 2010 and the implementation of various public education and awareness programs. Recent Canadian Health Survey data indicate that the blood lead levels of children in the Flin Flon area appear to be slightly above the levels found in other Canadian children, although levels in Flin Flon area children are similar to those in children across the United States.
Also, in keeping with recommendations from the 2009 Human Health Risk Assessment and Exposure Evaluation studies, the provincial and Hudbay air monitoring programs continued. Monitoring confirmed a sharp drop in lead levels measured in air since the smelter closed in June 2010, and with efforts to reduce the generation of dust.
For more detailed information about each of the studies, visit Learn More.