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  • You Asked

    What did the 2009 Human Health Risk Assessment and Exposure Evaluation find?

    Short-term risks associated with infrequent exposure scenarios were evaluated for air, soil and snow related exposures. The results of this evaluation indicated that on rare occasions some people may experience short-term and reversible minor health effects from exposure to metals in soil and air. These include irritation of the eyes, nose or throat; or aggravation of symptoms of those with asthma.

    Long-term risks are associated with regular and repeated exposure scenarios that may occur throughout a lifetime. Results are provided below:

    Copper

    • No elevated risks from exposure to copper were predicted.

    Selenium

    • No elevated risks from exposure to selenium were predicted.

    Cadmium

    • Air concentrations of cadmium could pose a low long-term health risk. However, increased cases of lung cancer in the Flin Flon area are not expected, given the small population size and estimated low risk level. The Hudbay smelter stopped operating in June 2010; this closure helped reduce the concentrations of metals in the air.

    • No significant increased rates of lung cancer were identified for the Flin Flon area within the Community Health Assessment.

    Methyl Mercury

    • Some fish in Flin Flon area lakes had elevated concentrations of mercury. Mercury is a naturally occurring element and most fish contain some, with older, larger fish accumulating the highest amounts. The mercury levels in fish generally appear to increase as you move further away from the Hudbay facility, which suggests that these concentrations are not related to Hudbay’s Flin Flon Metallurgical Complex.

    Inorganic Mercury

    • No elevated levels of inorganic mercury in the urine of children.

    Arsenic

    • Air concentrations of arsenic could pose a low long-term health risk. However, increased cases of lung cancer in the Flin Flon area are not expected, given the small population size and estimated low risk level. The Hudbay smelter stopped operating in June 2010; this closure helped reduce the concentrations of metals in the air.

    • No significant increased rates of lung cancer were identified for the Flin Flon area within the Community Health Assessment.

    • Levels of inorganic arsenic in the urine of children were not elevated. The community levels were very similar to the levels found in other Canadian communities where soil levels were not elevated.

    Lead

    • Measured blood lead levels in children from the Flin Flon area did not indicate immediate health concerns.

    • The blood lead results for Flin Flon area children 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 of the general population.

    • Blood lead levels in Canada have declined significantly over time. However, some of the latest studies on lead indicate that there may be slight developmental and cardiovascular effects even at low levels. The findings from the studies show lead exposure in Flin Flon is slightly higher than available population data but well below the current action levels for medical intervention.

    • Few children (about 2%) had measured blood lead levels above Health Canada’s current intervention level. As a precaution, a more sensitive reference point was used for the study; as a result, about 13% of the children tested were referred to a physician for follow-up.

    • Many factors were associated with the measured blood lead levels in Flin Flon area children including gender, area of residence, and the year that their house was constructed (age of house may indicate other exposures such as from lead in paint or pipes).

    How was exposure to metals evaluated in the Flin Flon Soil Study?

    This Soil Study measured metal concentrations in blood and urine samples from area children; the most direct way to evaluate human exposure is through biological samples.

    What did the study try to find out?

    The study investigated the following questions:

    • What is the current level of exposure in the bodies of children in the Flin Flon area?
    • Do Flin Flon area children have higher arsenic, lead, and/or inorganic mercury levels than residents living in other parts of Canada?
    • Are there any health risks from these levels of exposure?
    • What personal factors are associated with the levels of exposure, like place of residence, place of work, level of COC in soil, age, gender, diet, or personal habits?

    Why focus on children?

    If exposure is occurring among residents, it will be more apparent in children for the following reasons:

    • Children are usually more sensitive to environmental contaminants than adults,
    • Children are potentially exposed at higher levels – when you take their body size into account – because they eat, drink and breathe more than adults.
    • Behavior and habits are also important. Children’s normal activities, like putting hands in their mouths or playing on the ground, create additional opportunities for exposures.

    In short, if the average exposure levels in children are not elevated, it would be very unlikely for other age groups to have elevated levels.

    How did Flin Flon and Creighton residents participate?

    The study team contacted parents from a random sample and explained the study. Parents then voluntarily chose to participate or not. If they chose to participate:

    • Parents/guardians signed a consent form and participated in an interview in their own home,
    • A Collection Kit was left with them for urine samples; children provided small urine samples,
    • Samples were picked up the next morning by the study team, and
    • Children provided a small blood sample (finger prick); a time was arranged for parents to take their children to a specific clinic to provide the sample.

    What happened after residents participated?

    • The study team used interview answers and results from the urine and blood samples to answer the selected study questions,
    • Each child’s parents/guardians and their physician received the child’s results along with a description of results for the community overall; a local physician agreed to review the results of children who did not have a family doctor. The Principal Investigator, who is a physician, worked with the local physician to make sure that arrangements were made for a follow-up appointment for any child whose results were higher than a set limit.
    • All individual results remained confidential. No results were linked to specific individuals in any reports.

    Information was integrated into the overall Human Health Risk Assessment and reported back to the community.