What are the MOE soil quality criteria and what do they mean?
The Ontario Ministry of the Environment’sGuideline for Use at Contaminated Sites in Ontario revised 1997, includes soil and groundwater quality criteria to help assess contaminated sites and properties. These are not legislated “action levels” - properties with levels over the criteria do not necessarily require immediate clean up. The criteria act as “trigger levels” for further study, and soil levels over the criteria do not suggest there is an immediate health concern from short-term exposure.

includes soil and groundwater quality criteria to help assess contaminated sites and properties. These are not legislated “action levels” - properties with levels over the criteria do not necessarily require immediate clean up. The criteria act as “trigger levels” for further study, and soil levels over the criteria do not suggest there is an immediate health concern from short-term exposure.

Decisions on the need to undertake action when the criteria are exceeded require consideration of factors such as:

• ¨ WWhether there is or is likely to be an adverse effect to human health and/or the natural environment;
• ¨ LLocal environmental conditions that could modify the availability and toxicity of metal concentrations in soils;
• ¨ AAn understanding of the relationship between the dose and the health effect response from all of the ways exposure to metals could occur;
• ¨ CCurrent and intended or future land use; and,
• ¨ The need for protection of groundwater.

A decision to undertake action to remediate soils would follow from consideration of these factors, plus any additional factors specific to a particular community. Before a decision is made, human health and/or ecological risk assessment(s) are often carried out to assess the level of risk to that particular community, identify the major contributing factors to risk, develop intervention levels for remediation (if warranted), and identify appropriate risk management measures.

Note: The MOE soil quality guidelines were updated in 2004 after the Sudbury Soils Study began. Readers should refer to the latest Ministry guidance documents for updated definitions and soil quality values.

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How were the Ministry criteria determined?
The soil quality criteria for most of the chemicals of concern in the Sudbury Soils Study (such as copper, nickel, arsenic and cobalt) are based on the toxicity of these elements to plants - not humans - and are derived for soils with a pH of 5.0 to 9.0.

These guidelines are based on sensitive plant species on which laboratory experiments were conducted. In some cases the test species are plants such as oats or wheat. These species may or not be relevant for Sudbury, which is why a site-specific risk assessment is being undertaken.

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Historic sampling since 1970 has revealed elevated metal levels in the Sudbury area. Why didn’t the Ministry act on this information until now?
Although elevated metals and arsenic concentrations in soil were known in the Sudbury area in the late sixties, there is now a better scientific understanding of the relationship between metals and arsenic levels in soil and potential health risks related to exposure.

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Why has the soil in Sudbury been sampled?
The MOE and Laurentian University collected soil samples throughout the Sudbury area in 2001. This was part of the work to assess the environmental impact of mining and smelting operations in the area over the past 100 years. The soil sample results were used in the human health risk assessment and ecological risk assessment of the Sudbury Soils Study. The purpose of the study is to better understand the potential for health and environmental impacts from long-term exposure to metal and arsenic levels in soils.

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What areas have been sampled?
The Ministry’s 2001 survey focused on taking samples from areas commonly used by people - especially children - such as public parks and beaches, schools, day care centres and residential areas. Efforts were focused on the City of Greater Sudbury and in the three industrial centres of Copper Cliff, Coniston and Falconbridge. The 2001 survey resulted in over 8,000 soil samples taken from hundreds of locations.

In conjunction with the Ministry survey, Golder Associates collected soil samples in and around the Town of Falconbridge, and Laurentian University collected samples near the industrial lands of Inco Ltd. and Falconbridge Ltd., as well as in more remote areas around Sudbury, to help define the extent of elevated metals and arsenic in soil.

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What chemicals were analyzed in the 2001 soil survey?
Soil samples were analyzed for 20 parameters, including: aluminum, antimony, arsenic, barium, beryllium, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, strontium, vanadium, and zinc.

These parameters were also included in the analysis of any other samples (air, water, vegetables, etc.) taken as part of the Sudbury Soils Study.

This analysis also included the six chemicals of concern (CoCs) for the Sudbury Soils Study – arsenic, cobalt, copper, lead, nickel and selenium.

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What are the findings of the 2001 MOE soil survey?
The sampling results confirm that emissions from over 100 years of mining, smelting and refining have resulted in elevated levels of metals and arsenic in soil over a large area. Levels of arsenic, cobalt, copper, lead, nickel and selenium are higher in the areas closest to the three smelting centers of Copper Cliff, Coniston and Falconbridge. These current findings are consistent with historical Ministry results.

Based on current information, the Sudbury & District Medical Officer of Health and the Ministry agree that there are no expected immediate health concerns related to these findings. Studies done in other mining communities with similar or higher levels of metals and arsenic in the soil have not shown any associated measurable health effects.

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Why was the Sudbury Soils Study necessary?
In recent years, several studies have shown that there are some areas in Sudbury - generally close to the historic smelting sites of Coniston, Falconbridge and Copper Cliff - with elevated levels of arsenic, cobalt, copper, lead, nickel and selenium in the soil. Although these elements occur naturally in soils, higher amounts, generally found in the top 5 cm of soil, occur as a result of historical and current mining, smelting and refining activities.

Since no previous studies have addressed the potential long-term exposure implications of Sudbury's soil metal levels and the possible risk they may present to both human health and the environment, the MOE has asked Vale Inco Ltd. and Xstrata Nickel (formerly Falconbridge Ltd.) to undertake the Sudbury Soils Study. It is one of the most comprehensive soil analyses and risk assessments ever done in Canada.

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What are the Chemicals of Concern (CoCs) for the Sudbury Soils Study?
The 2001 soil sampling program analyzed for 20 parameters, including: aluminum, antimony, arsenic, barium, beryllium, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, strontium, vanadium, and zinc. The data from the soil survey were examined and evaluated relative to three criteria:

1. LLevels of the chemical in local soils exceeds Ministry of the Environment (MOE) trigger levels for further study;

2. TThe chemical is found throughout the study area, or throughout one of our communities of interest (Sudbury core, Copper Cliff, Coniston, Falconbridge, Whitefish Lake First Nation and Wahnapitae First Nation);

3. TThe chemical is related to smelting activities.

Based on this evaluation 6 chemicals – arsenic, cobalt, copper, lead, nickel and selenium, were considered in the risk assessments. Cadmium was also included as a COC for the ecological risk assessment.

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What are Human Health and Ecological Risk Assessments?
A risk assessment determines the potential for adverse health effects to occur from exposure to chemicals. Risk assessments are conducted for human health effects and ecological effects (e.g., effects on plants, fish and wildlife). These assessments are done to determine the potential, type and severity of risks, and if actions should be taken to reduce the potential for adverse effects.

Risk assessment methods typically use mathematical models to calculate the theoretical health risk to humans, plants, wildlife and the natural environment from exposure to a substance using an exposure pathways analysis. Actual (as opposed to theoretical) exposures can be measured for humans and some ecological species, such as plants and fish. Actual impacts to some ecological species, such as plants and fish, can also be measured.

For the Sudbury Soils Study, the Human Health Risk Assessment (HHRA) assessed potential human health risks related to exposure to arsenic and metals from soil, water, food and air. The Ecological Risk Assessment (ERA) examined the potential risks to terrestrial and aquatic wildlife of the Greater Sudbury Area from metals and arsenic in soils.

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What will be the end result of the Sudbury Soils Study?
The Sudbury Soils Study produced three (3) large final reports: • Volume 1: Study Background and Organization • Volume II: Human Health Risk Assessment • Volume III: Ecological Risk Assessmennt

All these reports and summary reports can be viewed on this website.

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Who are the partners in the study? Who will ensure it is done properly? Who is paying for all of the work?
Six organizations identified as major stakeholders in the maintenance of a healthy environment in Sudbury took the responsibility to oversee this extensive soil study. These groups, which comprise the Technical Committee for the Sudbury Soils Study, include the Ministry of the Environment (MOE), the Sudbury & District Health Unit (SDHU), the City of Greater Sudbury, Health Canada’s First Nations & Inuit Health Branch, Vale Inco and Xstrata Nickel.

The Technical Committee is responsible for overseeing this important work. Both Vale Inco and Xstrata Nickel paid for all costs associated with the risk assessments. On the recommendation of the Technical Committee, Vale Inco and Xstrata Nickel hired the SARA Group to undertake the actual studies.

To ensure that the process in completing these studies is transparent and fair, the Technical Committee has brought on an independent Process Observer to observe and report back to the community on the progress of the work and the process being used. All expenses related to the Independent Process Observer were shared equally by all six partners on the Technical Committee.

There was also a Public Advisory Committee (PAC) consisting of a Chair, residents of the City of Greater Sudbury, and Wahnapitae First Nation and Whitefish Lake First Nation. The role of the PAC was to provide public input to the Technical Committee on the study process, in addition to ongoing public consultation initiatives.

The Technical Committee also appointed two Scientific Reviewers to provide additional input and professional advice throughout the HHRA and ERA studies.

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Can any member of the Technical Committee unduly influence the results of this study?
The Sudbury Soils Study process includes several checks and balances so that no one member of the Technical Committee can unduly influence study design, data collection or other aspects of the study. All decisions of the Technical Committee are arrived at by consensus, and not a single vote was taken. More importantly, no member of the Technical Committee would ever want to unduly influence or control the study – it’s simply too important.

To ensure that the process in completing these studies is transparent and fair, the Technical Committee brought on an independent “Process Observer”, who attended all Technical Committee and Public Advisory Committee meetings to review and report back to the community on the progress of the work and the process being used.

Also, the Technical Committee was made up of environmental professionals and scientists who are recognized by their peers in their respective fields. Collectively, they have the expertise to oversee this important work. The members of the Technical Committee are not conducting the study; they hired the SARA Group, a group of expert consultants in human health and ecological risk assessments, to undertake the study.

The Sudbury Soils Study follows decades of land reclamation work in Sudbury that introduced grass cover to once-barren rock outcrops and saw millions of trees planted and nurtured to grace the Sudbury skyline. The success of that effort is owed to the cooperation and commitment of community partners working together for a common goal. The Sudbury Soils Study is an extension of that work, and extensive studies conducted by the Ministry of the Environment over the past 25 years. Members of the Technical Committee – most of whom work and live in Greater Sudbury and are raising their families here – were equally committed to the success of this study for the collective good of all Sudburians.

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How were Technical Committee members chosen?
The Sudbury Soils Study is an extension of the very successful and highly visible Land Reclamation Program initiated in 1978 by the City of Greater Sudbury and involving several partners, including the Ministry of the Environment, Vale Inco and Xstrata Nickel. The additional emphasis on human health aspects associated with the current soils study initiated participation by the Sudbury & District Health Unit and Health Canada’s First Nations and Inuit Health Branch. Collectively, members of the Technical Committee have the health and environmental expertise needed to oversee this study.

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What was the role of the Independent Process Observer?
The Independent Process Observer role was created to further ensure the public transparency and integrity of the entire Sudbury Soils Study process. The Independent Process Observer did just that – observed the study process and all decisions. Based on those observations he reported to the public - applauding the process where it’s working, challenging the process where it’s not and suggesting changes where appropriate. His quarterly reports to the public were distributed widely through the Sudbury community and are available at all public libraries and on-line at www.sudburysoilsstudy.com - the official website of the Study. The FINAL PO report is also available at this website. The Process Observer was Franco Mariotti, a prominent local scientist and a tireless advocate of environmental stewardship in Sudbury.

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What was the role of the Public Advisory Committee?
The Public Advisory Committee served as a public sounding board for Technical Committee decisions and communications efforts through the study. The volunteer members were selected as a representative sample of the Sudbury community, with no existing biases, affiliations or conflicts with any aspect of the study. Public Advisory Committee was committed to ensuring the soils study was conducted appropriately with proper public consultation and communication. The role of the committee was not to review the science of the study, but to comment on the process itself as seen by the average Sudburian.

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Did the study consider slag or tailings?
In addition to airborne releases from the smelter stacks, the Sudbury Soils Studyalso included evaluation of dust from slag and tailings as a source of metals and particulates into the environment. This was done through a year-long air monitoring program in and around the City of Greater Sudbury.

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Did this study look at fall- out of particles from air?
Yes. Airborne releases from the smelter stacks were evaluated in this study. A year-long air quality monitoring study was conducted as part of the human health risk assessment, with samplers in nine locations throughout the Greater Sudbury Area, and one background sampler located at Windy Lake Provincial Park. These units collected air samples over a 24-hour period every six days, following the protocol set by the National Air Pollution Surveillance Network (NAPS). Samples are then sent to the laboratory for analysis for a suite of metals. This information will be in addition to that already collected by the current air monitoring network run by Vale Inco Xstrata Nickel, and the Ministry of the Environment.

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AHow do the concentrations in soil here compare to other mining communities (e.g., Wawa, Port Colborne)?
The soil metal and arsenic levels currently known to exist in Sudbury are generally comparable to, and in some cases, lower than those found in other Ontario mining and smelting communities with elevated metals levels from historical mining activity.

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DAre soil metal levels getting better or worse?
There is no clear indication at this time that soil metal concentrations have changed within the past two or three decades. However, atmospheric emissions from Vale Inco and Xstrata Nickel have been reduced by over 95% in recent years so it is expected that soil metal levels will decline over time.

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Were soil samples collected from every home?
The MOE sampled about 440 homes in the City of Greater Sudbury during their 2001 soil sampling program. Samples were collected from most neighbourhoods in the city. As well, thousands of soil samples have been taken in recent years from the Sudbury area, which provide a good estimate of soil metal levels. All residential property owners who were involved in the survey were forwarded a letter with their individual sampling results on June 19, 2003.

A vegetable garden survey conducted by the SARA Group as part of the Sudbury Soils Study in the summer of 2003 allowed for the sampling of approximately 85 properties in the Sudbury area, collecting both vegetable and soil samples. There are no plans to collect and analyze more soil samples in the Sudbury area. The results of the 2001 MOE sampling program available on this website.

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The findings of the 2001 MOE soil survey confirm that metals and arsenic levels exceed the Ministry’s own contaminated sites criteria. Why is there no plan to remove the contaminated soil?
The results of the Human Health Risk Assessment did not identify the need to remove soil from any specific home in Sudbury. Residents concerned with soil quality at their home can contact the Ontario Ministry of the Environment for further information.

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If soil remediation is needed, will Inco and Falconbridge assume responsibility?
Yes, the companies are prepared to undertake remediation where unacceptable health and ecological risks associated with metals in the soil have been identified.

Both Vale Inco. and Xstrata Nickel have accepted and publicly declared that they will assume responsibility for required remediation, and they have the track record to back up that commitment. In the last 20 years, more than $1 billion has been spent on environmental initiatives in Sudbury.

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Do the metals and arsenic being studied accumulate in garden vegetables?
Many of the metals and arsenic being studied as part of the Sudbury Soils Study do not accumulate in garden produce in a significant way. For example, edible portions of plants seldom accumulate high levels of arsenic, because arsenic at high levels is more likely to kill the plant before concentrations reach levels of concern for human health. Cobalt, copper and nickel concentrations in garden produce are generally at much lower levels than those found in soils. A home garden study was conducted in the summer of 2003, which measured concentrations of metals and arsenic in gardens throughout the Sudbury area. Results of that study were included in the human health risk assessment which indicated that metal levels in home-grown vegetables in the Sudbury area did not pose unacceptable risk to people.

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What i was the purpose of the air sampling program?
The air sampling program was put in place to collect information and data on the concentrations of metals in the atmosphere in the Greater Sudbury Area, to allow us to estimate exposures to people, wildlife and vegetation.

We selected 10 locations, to sample for a one year period starting in October 2003. This data were used as part of the exposure assessment for the Human Health Risk Assessment (HHRA) of the Sudbury Soils Study.

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Why was particulate matter collected?
Particulate matter was sampled because it is toxicologically significant for people in the Sudbury area. Three different particulate sizes were collected - TSP (particulate matter less than 40 microns in diameter, retained in the human nose if present in the air), PM10 (particulate matter less than 10 microns in diameter, retained in the throat and upper lung if present in the air) and PM2.5 (particulate matter less than 2.5 microns in diameter, retained in the lower lung if present in the air).

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What methodology was used to collect air samples?
The methods used were developed in conjunction with the Ministry of the Environment, and are based on methodology used province-wide for air sampling. The US Environmental Protection Agency also has a standard methodology, which was consulted in preparing the SARA Group methods. The MOE samplers used by Vale Inco and Xstrata Nickel follow the same protocol, and the Soils Study was able to integrate these monitoring sites into the program for the Sudbury Soils Study.

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How were the air sampler sites chosen?
Sampling sites were selected in conjunction with the MOE that were representative of populated areas within the Greater Sudbury Area. One control site was also selected at Windy Lake Provincial Park, to be representative of air concentrations outside the influence of the smelters.

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What were gaseous substances not measured?
The soils study did not measureSO2 because there is an existing SO2 monitoring network in place, overseen by Vale Inco, Xstrata Nickel and the MOE. Also, SO2 is not considered a Chemical of Concern for the risk assessments.

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Isn’t any level of exposure to metals and arsenic too much?
People everywhere are exposed to chemicals, like metals and arsenic, as part of their daily lives. This exposure comes predominantly from food and drinking water. Soil is an additional exposure pathway. The effects of exposure to any substance depend on the type of exposure (oral, inhalation, or skin contact), the quantity of exposure, type of substance and its concentration, and the length of time of exposure. Additional factors that must be considered are a person’s age, gender, diet, family traits, lifestyle and health status.

Many metals are essential nutrients and arsenic is a naturally occurring substance in seafood. The body naturally regulates levels of metal and arsenic, which are readily excreted unless excess exposure occurs. Removal of exposure of a person to excess levels of many metals allows the body to eliminate these substances, and levels in the body will generally return to normal.

Based on the current understanding of soil metal and arsenic levels in Sudbury, and health risk assessments and health studies conducted in other Ontario communities, both the Ministry and the Sudbury & District Medical Officer of Health believe there is no expected health concern from exposure to metals in soils in the Sudbury are.

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Is it safe to garden? And to eat home-grown vegetables?
Yes. The results of the vegetable garden survey and human health risk assessment did not identify unacceptable risks from eating home grown produce in Sudbury. The concentration of certain metals were higher in some vegetables grown in soils with elevated metal levels in Sudbury compared to other Ontario locations but the concentration and frequency of consumption do not pose a risk to people eating these vegetables. It is recommended that all garden produce be washed thoroughly, and root vegetables peeled before eating in order to prevent any soil particles from being ingested. Other simple precautions, such as hand washing and wearing gloves while gardening, can be taken to reduce unnecessary exposure to any metals in garden soils.

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Is it safe to consume fish from Ramsey Lake and the Wahnapitae River?
There are no restrictions on eating sport fish specific to the Sudbury area due to any metals or arsenic. Throughout Ontario, there are various restrictions on eating sport fish due to mercury. The Guide to Eating Ontario Sport Fish gives consumption advice for sport fish from Ontario waters and is published every two years by the MOE in cooperation with the Ministry of Natural Resources. Check the guide for possible fish consumption warnings related to mercury for the waters you intend to fish in.

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Is occupational exposure being considered in the Sudbury Soils Study?
Occupational exposure is not being directly considered in the Sudbury Soils Study. Both Vale Inco and Xstrata Nickel have Occupational Health and Safety Committees that monitor and evaluate occupational exposures in conjunction with the Ontario Ministry of Labour. In contrast, the Sudbury Soils Study is the first time that exposure and risk to residents, including children, has been assessed. Therefore, only environmental exposures to residents will be evaluated in this study.

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Is there a concern about metal exposure due to dust in my home?
Indoor dust can contain metals from a variety of sources including outdoor soil, atmospheric emissions, flaking paint, pets and cooking just to name a few. Good housekeeping to reduce dust by cleaning, using mats, and regularly replacing furnace air filters is always advisable to maintain a healthy indoor environment.

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Do I need to buy bottled water?
Drinking water metal and arsenic levels are monitored regularly by both municipal and provincial regulatory authorities, and levels of these chemicals within your drinking water are low and are not believed to pose a potential health concern. The City of Greater Sudbury monitors different elements within its municipal water supplies on a quarterly basisAs part of the Sudbury Soils Study a survey of drinking water from private wells and surface sources was conducted. Metal levels are not elevated in potable water in Sudbury and is safe to consume. A summary of current water records for Sudbury’s public supplies is available here.

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Can my children play on the beach? Playgrounds? Backyard?
The Sudbury & District Health Unit has stated that no precautions are necessary when using Greater Sudbury Parks. The City of Greater Sudbury supports this statement. The concentrations of metals and arsenic measured in the Sudbury area are similar to those found at other mining and smelting sites around Ontario where previous risk assessments have found no adverse health risks Sand and soil from beaches and playgrounds and school yards were all sampled as part of the 2001 soil survey. There were no instances of elevated metal concentrations at these locations.

There are a number of simple common sense steps people can take to further reduce exposures, such as washing after playing outdoors, hand washing before eating, supervising children to discourage them from putting soil or sand in their mouths, and keeping toys and mouthable objects clean. More information can be found on the websites of the MOE (www.ene.gov.on.ca), SDHU (www.sdhu.com), and this website.

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How can I get more information on metals and arsenic, and decrease my risk?
The MOE has developed Fact Sheets for several metals, which are also available on this website Alternatively, the Centre for Disease Control in Atlanta, Georgia provides excellent information on metals and ways to decrease risk (www.atsdr.cdc.gov), and Health Canada has provided a fact sheet on arsenic in drinking water (www.hc-sc.gc.ca/english/iyh/environment/arsenic.html).

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How do metals and arsenic get into my body?
Chemicals can enter the body in many different ways, including ingestion of food from the store and from your garden, ingestion of drinking water, inhalation of particles in the air, and direct contact with soils. However, many of these exposures will be very small.

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How do health concerns and cancer rates in Sudbury compare to the rest of Ontario/Canada?
The Sudbury & District Health Unit has not identified a higher incidence of any diseases related to metal or arsenic exposure in soils in the Sudbury area relative to other regions of Northeastern Ontario.

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Why were samples of blood, hair or other human tissues not collected and analyzed for the risk assessment?
The human health risk assessment did not indicate the need for collection and analysis of metals in human tissue. In most cases it is difficult to interpret the results of these types of measurements in a meaningful way. Lead and arsenic are exceptions. IF anyone is concerned about exposure to lead, monitoring can be arranged by their general physician for blood analysis. In addition, an Arsenic exposure study was conducted in the Town of Falconbridge. Although soil arsenic levels were higher in this community than in a nearby reference community, no additional arsenic was present in people living in the Town of Falconbridge compared to the reference community. The results of that study can be found in Appendix N of Volume II of the Sudbury Soils Study (Human Health Risk Assessment).

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How can health be determined without taking human tissue samples?
Considerable effort was dedicated in the Sudbury soils study to measure the concentration of metals in the media to which people are exposed (ie. Drinking water, dust, air, food). Sophisticated mathematical models, which simulate the movement of chemicals through the environment and within the body, were used to estimate total exposures for the residents of Sudbury. These models are based on the most recent scientific and regulatory guidance, and have been used in many similar assessments throughout Canada. Results of these estimates are generally conservative and tend to over-estimate potential exposures and risks. This overestimation is designed to be extra protective of human health and the environment.

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Are children who play outdoors under any risk at all? If so, what actions can we take to prevent additional exposure?
Children, due to their active play combined with lower body weight, tend to have greater exposure to any element or substance than adults. Infants and young children also experience mouthing activity, which increases their exposure to substances in the soil and dust on their hands, surfaces and toys. Their size and play habits also contribute to air-borne exposures as they are closer to the ground and typically come in closer contact with soil and flooring through their play on the ground.

For these reasons, the study focused on metal exposure to toddlers (7 months to 4 years old). There were no unacceptable health risks predicted to arsenic, copper, cobalt, nickel or selenium in soil. Also, there was no increased risk associated with typical exposure to lead in the environment. However, levels of lead in some soil samples indicated the potential for risk of health effects for young children in the neighbourhoods of Copper Cliff, Coniston, Falconbridge and Sudbury Centre. Anyone concerned about exposure to lead should contact either the Ontario Ministry of the Environment or Sudbury and District Health Unit.

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Are some people at greater risk than others?
Some individuals will be at greater risk than others, for a variety of reasons. Some people will be more sensitive to exposures due to genetic factors, nutritional considerations, age and other lifestyle factors (such as smoking). Likewise, exposure will be higher in some individuals who engage in activities and behaviours (diet, occupation) that increase their exposure. From the outdoor environment, these would include all activities that increase time spent out of doors and interactions with the soil. However, increased exposure does not necessarily mean increased "disease" or health problems.

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What is arsenic?
Arsenic is a naturally occurring element widely distributed in the earth's crust. In the environment, arsenic is combined with oxygen, chlorine, and sulfur to form inorganic arsenic compounds. Arsenic in animals and plants combines with carbon and hydrogen to form organic arsenic compounds.

Arsenic in soil occurs naturally, and is higher in some places than others due to geological conditions. Arsenic is found in higher than background concentrations in mine tailings or where there are airborne emissions from mining activities that deposit on the ground.

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How can I reduce my exposure to metals such as nickel, lead and arsenic?
Although no special measures are needed to reduce exposure, the Sudbury & District Medical Officer of Health has recommended to residents of Falconbridge that the following steps be taken:

• Wash hands before eating;
• Wash children’s hands and faces before meals if they’ve been outside;
• Clean household dust regularly with a damp mop/cloth and clean heating ducts;
• Use removable rugs at doorways /entrances;
• Rinse garden vegetables outside and then wash them thoroughly (peel the outer skin of root vegetables);
• Brush pets outside and do it often to reduce dust inside;
• Avoid well water that shows excessive metal and arsenic levels;
• Keep children’s toys and play areas clean while discouraging mouthing activities such as eating dirt or sucking dirty objects;
• Wear gloves during excavations and digging in soil;
• Wear protective masks to avoid inhaling dust when working in dusty conditions;
• Cover soils where possible (e.g. with grass, paving stones, decking); and,
• Eliminate tobacco smoking as it contributes to arsenic exposure.

Information fact sheets on nickel, cobalt, lead, copper, and arsenic are available from the Ministry’s Sudbury District Office and can be found on the Ministry Web site at www.ene.gov.on.ca and this website. These fact sheets contain easy to follow common sense ways to reduce exposure to environmental contaminants.

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How might I be exposed to arsenic?
Exposure means coming in contact with something, followed by uptake into the body. You can be exposed to arsenic through:

• Food, drinking water, or breathing air containing arsenic;
• Arsenic in soil from human activities;
• Arsenic compounds dissolved in water;
• Eating fish and shellfish, but the form of arsenic in fish is generally not considered harmful compared to inorganic forms of arsenic in water;
• Cigarette and tobacco smoke;
• Pressure treated wood and arsenical pesticides; and,
• Soil and dust in areas with high natural levels of arsenic in rock.

Food and drinking water are the main sources of arsenic exposure in Canada. In general, arsenic from soil and air provide less than 0.01 and 0.2% of total exposure to arsenic in adults. Canadian data indicate that dust and soil provide about 0.4 to 3% of the total daily exposure to arsenic in all age groups, with children’s total daily exposure being about 4-9% from soil and dust. In the United States, about 92% of arsenic exposure is from food, and about 7% is from drinking water. Smoking also provides exposure to arsenic.

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How much arsenic is normally in drinking water?
The concentration of arsenic normally in drinking water is very low, around 5ppb (parts per billion) or less. The drinking water quality guideline in Canada for arsenic is 25ppb (0.025 milligrams per litre), and Health Canada has created a fact sheet on arsenic in drinking water (www.hc-sc.gc.ca/english/iyh/environment/arsenic.html).

Arsenic cannot be seen or tasted in drinking water. Special tests must be carried out to determine its presence.

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What are the possible economic effects on the city?
Economic concerns of soil contamination in Sudbury are no different that those in any industrial or major city in the rest of Canada. Examining the possible economic consequences of metals present in Sudbury soils is beyond the scope of the Sudbury Soils Study. However, it is important to remember that Sudbury was historically founded because of the high mineral levels in the soil and bedrock. Overall, the results of the Human Health risk assessment predicted little risk of health effects on Sudbury residents associated with metals in the environment.

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