| Frequently Asked Questions (FAQ) |
| Cobalt Soil Study |
Frequently Asked Questions (FAQ) |
Cobalt Soil Study
QUESTIONS & ANSWERSWhat is an MOE Screening Level Human Health Risk Assessment (SLHHRA) and why was it done in Cobalt? As part of their mandate to protect the environment, the Ontario Ministry of the Environment (MOE) is studying the environmental impact of current and historic mining operations in several regions of Ontario. The MOE conducted soil sampling programs in mining communities across the province to determine areas needing further investigation. Within Cobalt and Coleman, the MOE had identified the Heritage Silver Trail as an area of concern where further study was conducted to determine the potential risks to human health from exposure to soils with elevated levels of heavy metals and arsenic.. This risk determination process is called a SLHHRA. MOE soil samples taken in Cobalt and Coleman at 4 sites along the Heritage Silver Trail revealed elevated levels of arsenic and other metals along the trail. The MOE advised the health unit that exposure to these levels may represent a potential health risk to some trail visitors under certain conditions.
Why did the MOE take soil samples on the Heritage Silver Trail? Working from a list of communities with current or historic mining operations, the MOE conducted sampling programs in several Ontario communities including Port Colborne, Deloro, Wawa, and Sudbury. Included in the sampling program was the Cobalt and Coleman vicinity, because it was an area that once had 100 mines in operation, where focus was then drawn to the Heritage Silver Trail. For this reason, soil samples were taken at 4 sites along the Heritage Silver Trail due to knowledge of its historical use, and its present day use as a recreational area that is accessible to a large number of visitors and residents. Similar studies have been conducted in other Ontario mining communities, including Sudbury and Deloro, where metals including arsenic have been detected at elevated levels in the environment. In both cases, health officials and environmental risk assessments have concluded that there are no expected immediate risks to human health under normal exposure conditions. For more information on these studies, go to: Sudbury Soils Study: http://www.sudburysoilsstudy.com Deloro: http://www.ene.gov.on.ca/envision/techdocs/3794e.htm
Where can I get more information on health concerns related to heavy metals and arsenic? The Timiskaming Health Unit is committed to keeping the community fully informed of all public health issues relating to the Heritage Silver Trail area, and the environmental legacy of mining in our community. The Health Unit has developed Fact Sheets for reducing exposures to Heavy Metals and arsenic, which we have posted on our website (www.timiskaminghu.com). They are also available for pick-up at any of our local offices, the Cobalt Library, Town Hall, and Post Office. For more information call our information line at 647-4305 or 1-866-747-4305. Additional sources of information include:
Arsenic is a naturally occurring substance in the earth's crust. It occurs in several forms, often in compounds with other chemical elements. Arsenic and all of its compounds may present health risks at high doses, under certain exposure conditions. Inorganic arsenic - arsenic combined with oxygen, chlorine or sulfur - is thought to present the highest potential health risk, while most organic forms of arsenic are relatively less toxic. In its solid state arsenic appears as a silver-gray, brittle semi-metal that tarnishes in the air. It is about the 52nd most common chemical element on the earth. Arsenic has been used in numerous industrial applications over the years. It is used in combination with other materials in pigments and insecticides. Arsenic also has a long history of medical applications; before penicillin was developed, an arsenic compound was used as a treatment for some infectious diseases. Arsenic is often used in the manufacture of ammunition and semi-conductors, and may be contained in some preservatives for exterior wood structures, tanning and taxidermy. Arsenic may be present in mine tailings or where there are airborne emissions from mining activities. For more information on arsenic, its properties and health effects, visit Heath Canada's website at: http://www.hc-sc.gc.ca/english/iyh/environment/arsenic.html -- or check the ToxFaQs on Arsenic from the Agency for Toxic Substances and Disease Registry (ATSDR) at: http://www.atsdr.cdc.gov/tfacts2.html.
How might I be exposed to Arsenic? Potential health risks associated with exposure depend on a variety of factors such as the nature of the substance, amount of the substance present (the dose), the route of exposure (skin contact, ingestion, inhalation) and the length or duration of exposure. Exposure can result in the following ways: · Ingesting food or drinking water containing arsenic · Breathing in air containing traces of arsenic · Coming in direct contact with arsenic in soil or surface water on the skin · Living in areas with unusually high natural levels of arsenic in rock For more information on steps you can take to reduce exposures and protect your health, contact the Health Unit at 647-4305 or 1-866-747-4305 or visit our website at www.timiskaminghu.com.
How does arsenic react in the human body? The body naturally regulates levels of metals and arsenic, which are readily excreted unless excess exposure occurs. Minimizing our exposure to excess levels of metals allows the body to eliminate them naturally, which significantly reduces the risk of potential health effects. More information is needed to determine more conclusively the potential public health concerns associated with the legacy of mining in our community. The Health Unit is committed to encouraging the development of an open and transparent public process that will help this community determine the best course of action to take.
How can Arsenic affect my health? The effects of exposure to any substance depend on the route of exposure (ingestion, inhalation, or skin contact), the quantity of exposure, type of substance and its concentration, and the length or duration of exposure. Additional factors that must be considered are a person's age, gender, diet, family traits, lifestyle and health status. Arsenic is a naturally occurring substance in the earth's crust and presents no unacceptable health risk under normal conditions. Occasional, short-term contact with water or soil containing elevated levels of arsenic is unlikely to cause serious health effects; however, long-term exposure to high levels may lead to health concerns. Symptoms associated with ingesting elevated levels of arsenic may include nausea and vomiting, abnormal heart rhythm, and a sensation of pins and needles in hands and feet. Skin contact may cause redness and swelling. Ingesting or breathing low levels of arsenic over a long period of time may cause a darkening of the skin and the appearance of small corns or warts on the palms, soles, and torso. People experiencing any of these symptoms are advised to contact their physician. The body naturally regulates levels of metal and arsenic, which are readily excreted unless excess exposure occurs. Minimizing our exposure to metals allows the body to eliminate them naturally, which significantly reduces the risk of potential health effects.
How can I tell how much Arsenic I've been exposed to? Under normal conditions, low levels of arsenic are flushed by the body very soon after exposure, making it difficult to determine quantity. Long-term exposure may be measurable in urine, depending on the amount and length of exposure. If you are concerned that you may have been exposed to elevated levels of arsenic, or if you are experiencing any related symptoms, consult with your family doctor.
Are children at risk when playing in private playgrounds, sandboxes etc.? The current health advisory is based on the MOE report, which focuses only on environmental conditions along Heritage Silver Trail. Since no soil samples were analyzed from residential properties, no data is currently available. Due to their active play behaviours combined with lower body weight, children tend to have greater risks of exposure to environmental substances than adults. Infants and young children also experience mouthing activity, which increases their exposure to soil and dust on their hands, surfaces and toys. Their size and play habits also contribute to airborne exposure as they are closer to the ground and typically come in closer contact with soils. The SLHHRA study on the Heritage Silver Trail assessed exposures to toddlers (7 months to 4 years old). However, the exposures and risks for individual children will depend on a number of factors, including where and how long they play in the study areas, the types of activities they participate in, and the concentrations of arsenic and metals in the play locations. If you are concerned about soil conditions in your area, there are a number of steps you can take to reduce potential exposures of children:
Are some people at greater risks than others? Exposure to substances in the environment may affect people in different ways, and higher exposures do not necessarily mean increased health risks for everyone. Some individuals will be at greater risk than others, for a variety of reasons including occupation, genetic predisposition, diet, age and other lifestyle factors (such as smoking). Exposure to higher than average levels of arsenic occurs most commonly in some industrial workplaces, near hazardous waste sites, or in areas with high natural levels. The Timiskaming Health Unit is committed to working with our government and community partners to develop solutions to address potential public health issues associated with the legacy of mining in our community. What is the definition of chronic exposure? Long-term (chronic) exposure is defined as occurring over a number of years of a person's lifetime. The Agency for Toxic Substances and Disease Registry (ATSDR) defines chronic exposure as a duration of greater than or equal to one year. (ATSDR, USA, Toxicological Profile for Arsenic, 1993, pg. 7) Symptoms of chronic exposure to arsenic may include skin changes, usually on the hands and feet, gastrointestinal effects including nausea, diarrhea, and abdominal pain. For more information on arsenic and its health effects, go to the ATSDR website at: http://www.atsdr.cdc.gov/tfacts2.html
What is the definition of acute exposure? Short-term (acute) exposure is defined as occurring over hours or days. The Agency for Toxic Substances and Disease Registry (ATSDR) defines acute exposure as that of less than or equal to 14 days. (ATSDR, USA, Toxicological Profile for Arsenic, 1993, pg. 7) The exposure duration used in the MOE study was four to eight hours. Acute exposure to arsenic may result in a skin rash, a pins and needles sensation of the hands and feet, gastrointestinal effects including nausea, diarrhea, and abdominal pain, and respiratory symptoms including cough and irritation of the mucous membranes. The MOE report and our toxicologist determined that acute exposure to the levels of arsenic along the Heritage Silver Trail may represent a higher potential risk to children and expectant mothers. The body naturally regulates levels of metal and arsenic, which are readily excreted unless excess exposure occurs. Minimizing exposure to excess levels of metals allows the body to eliminate them naturally, which significantly reduces the risk of potential health effects.
What is the risk to my pets? Are they exposed? How can exposure affect them? Consult with your veterinarian if you are concerned about your pets' possible exposure to arsenic or other substances in the environment.
Does this affect our drinking water in the Cobalt area? The municipal drinking water source presents no unacceptable risks related to elevated arsenic and other heavy metals along the Heritage Silver Trail. Both municipal and provincial regulatory authorities monitor our drinking water throughout Timiskaming, to ensure that it meets all health-related Ontario Drinking Water Standards. Arsenic and other heavy metals in untreated water can come from several sources. You are advised not to consume water from uncontrolled sources such as lakes, rivers, springs and ground water. Homeowners on a private drinking water supply are encouraged to have their water quality tested annually for arsenic and other metals. If high levels of metals are detected, water treatment is strongly recommended.
Why are warning signs posted around Cobalt Lake now? Why weren't they posted sooner? The warning signs have been posted as a precaution to advise visitors to Cobalt Lake that exposure to the lake water could potentially lead to health effects under certain conditions. More information is needed to fully define the environmental conditions in the lake. Until then, minimizing exposure to excess levels of arsenic significantly reduces the risk of potential health effects. Where there is no exposure, there is no risk. As in many similar communities, historic mining activities in Cobalt disposed of mining waste rock, or tailings, directly into lakes. While we have long recognized that these tailings contain elevated levels of metals and arsenic, science now has a better understanding of the relationship between metals in water and soil, and the potential health risks related to exposure. Test results for water samples taken at Cobalt Lake indicate that arsenic levels do not meet provincial drinking water guidelines. While the lake is not a source of drinking water, the comparison to drinking water guidelines is made because there are no measurable limits established for recreational water. Our objective in posting the signs now is to ensure that residents and visitors are aware of this situation in advance of the summer season, when recreational use of the lake increases.
I swam in Cobalt Lake in previous years. Should I be concerned? At this time, the Health Unit has not identified any broad-based symptoms associated with metal exposures in the community. If you have individual health questions or are experiencing any symptoms that could be related to environmental exposures, you are advised to consult with your family physician. This is the best source of information regarding your personal health profile.
Why are beaches not routinely tested for chemicals? Currently, there are no enforceable water quality standards in Canada for recreational water, due to lack of conclusive scientific information on exposure risks. Water quality decisions are based on microbiological quality, aesthetic quality (e.g., presence of odour or visible oil and grease) and other factors considered in the environment health assessment of the beach, (e.g., proximity to industrial discharge). Even with no federal or provincial standards in place, the Medical Officer of Health has the authority to post health advisories on a beach if potential risks to human health exist. There is now a better scientific understanding of the relationship between metals and arsenic levels in water and soil, and the potential health risks related to exposure.
|
|
Last Modified: 9/23/2005 1:50:11 PM |
Printer Friendly Version |
back |  |
forward |  |
home |  |
search |  |
top |