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Follow-up petition on cleanup of the Sydney Tar Ponds and Coke Ovens

Petition: No. 140B

Issue(s): Air quality, environmental assessment, human health/environmental health, toxic substances, and waste management

Petitioner(s): Mary Ruth MacLellan and James Argo

Date Received: 22 March 2006

Status: Completed

Summary: This follow-up petition raises concerns about toxic substances released from the Sydney Tar Ponds and Coke Ovens site and seeks additional information on the joint review panel currently being carried out under the Canadian Environmental Assessment Act. In particular, the petitioners ask questions about the cleanup standards, the criteria to be applied during remediation, and the health effects of dioxin and furan released from the site.

Federal Departments Responsible for Reply: Environment Canada, Health Canada


22 March 2006

Sheila Fraser
The Auditor General of Canada
240 Sparks Street
Ottawa, Ontario
K1A 0G6


Petition #140: Releases of Dioxins during Remediation of Sydney Tar Ponds and Coke Ovens Lands

Dear Ms. Fraser:

The Cumulative Health Effects associated with residency in Cape Breton County, NS from about 1950 to 2006 have been documented in our report submitted to the Joint Review Panel. We refer to the re-exposure to dioxins of a population with a substantial pre-existing body burden from living at home as the "Sydney Scenario". This scenario unfortunately affects all persons resident in Cape Breton County. The issue of exposure and re-exposure to dioxin and dioxin-like chemicals is a cause of concern because of the potency of this class of chemicals to cause a wide variety of human morbidity at exceptionally low concentrations.

The Sydney Tar Ponds Agency (STPA) have answered our comments in part as follows (para. 2)

    "Any Dioxin and Furan releases will comply with applicable laws and regulations. The incinerator's permit will require that the dioxin and furan emissions be equal to or less than the Canada Wide Standard (CWS) for Dioxins and Furans, which is 0.08 ng/m3 in units of 2,3,7,8-TCDD Toxic Equivalents"

The Canada Wide Standard for dioxin release promulgated by the CCME is a guideline and as such, crafted to meet acceptance within all jurisdictions of Canada. Its sole concern is the release of Dioxins and Furans. There is no level of risk attached to the CWS of release, and, contrary to the ambiguous terminology it cannot compare to a standard or risk assessment. It is a guideline, an agreement, nothing more.

The CWS for dioxin release is a concentration at the stack gas exit. At no place in the document we reviewed is there any reference to the impact of this release on the surrounding community or environment. We have no confidence that the CWS is protective of the population receiving an additional dose of Dioxins and dioxin-like compounds from the proposed incinerator under the Sydney Scenario.

The WHO established a tolerable daily intake (TDI) for dioxin of 1 pg.1 TEQ/kg bw/d. This was prepared by reviewing the literature to determine a No Adverse Effects Level (NOAEL) or a reliable LOAEL for the most sensitive adverse effect. The LOAELS are observed in animals and were associated with body burdens from which a range of long-term human dally intakes of 14-37 pg/kg/d were calculated, in order to derive a TDI based on TEQ's the use of uncertainty factors (UF) had to be addressed. The potential differences in susceptibilities, and the differences in half-lives of elimination must be considered. A UF with a value of 10 is described a "reasonable" by the WHO.

Our concerns are based on several factors including; the choice of uncertainty factor; the age distribution of the population for whom the determination was made; the distribution of Body Mass Index (BMI) in the population; the distance of the population from the source or sources of dioxin; the magnitude of the pre-existing body-burden of dioxin; the duration of the pre-existing exposure, the gender distribution etc. All of these factors will affect the choice of uncertainty factor.

    We feel that the use of a "reasonable" value of an UF is not justified under exposure conditions such as the "Sydney Scenario". If the "reasonable" UF of 10 is acceptable for an unexposed person how can it be acceptable for persons who have been chronically exposed over many years in the Sydney Scenario. The pre-existing body-burden requires a conservative UF for example 50 to 100.

    Our preference would be 8 value derived as the 95th or 98"1 percentile from stochastic analysis.

Dioxins are known to induce adverse and biochemical effects at approximately the minimum risk level (MRL) dose. Recent work from Health Canada2 found that exposure of male rats to the (MRL) of 1 pg/kg/d of dioxins affected the Hypothalamic-Pituitary-Thyrold axis in the brain. They found that exposure at the MRL significantly increased thyroid stimulating hormone. The WHO notes that for some endpoints humans may be as sensitive as experimental animals to the adverse effects of dioxin and related compounds. Under many years of chronic exposure biochemical effects must be expected to show after a latency period. Dioxin exposure is associated with diabetes, heart disease and kidney disease. Cape Breton County has exceptional rates of diabetes and heart disease.

The biochemical effects observed in exposed humans at doses equal or close to the TDI may or may not develop into adverse effects. The WHO notes that certain subtle effects may be occurring in some sections of industrialized countries, at current intake levels of 2-6 TEQ pg/kg-bw/d and body-burdens of 4-12TEQ ng/kg bw.

    We feel that the pre-existing body-burden of dioxin or dioxin-like chemicals under the "Sydney Scenario" may have induced biochemical effects with adverse effects that have not yet appeared. The threshold dose has not been attained. Under the conditions of the Sydney Scenario a conservative UF is required.

The CCME have promulgated a Canada Wide Standard (CWS) for release of Dioxins and Furans that is 80 ng/m3. There is no obvious way to determine a relationship between the CWS and the risk based TDI from the WHO.

    We do not know if the CWS is protective of a re-exposed population with a pre-existing body-burden, (the Sydney Scenario) particularly in relation to recent work which has shown significant sub-chronic biochemical effects.

The CCME have released a CWS for mercury releases which the STPA will happily quote. The CWS for mercury is no different from the CWS for dioxin—a guideline crafted for acceptance within Canada. The potential locations of the proposed incinerator will ensure that under some conditions mercury releases covered by the guideline will be deposited in the wet-lands from which New Waterford draws its drinking water Wetlands and bogs are ideal conditions for the bio-transformation of mercury to methyl-mercury. Methyl-mercury is a potent neurotoxin that alters the development of the CNS in the developing fetus. What therefore is the relationship between the inorganic mercury in wetlands and methyl-mercury? How is the TDI for methyl mercury related to the CWS for mercury promulgated by the CCME? Given the target, fetuses and pregnant women, what is an acceptable risk-based release of mercury at the proposed incinerator that we are able to be certain is protective?

Therefore we petition you, the Auditor General, to ask from the Minister of Health and the Minister of Environment answers to these questions.

    In an exposure scenario as we have described with a population of men women and children born anytime after 1950 and having a pre-existing body-burden of dioxins and furans from the operation of the Coke Ovens over at least 50 years, a period of perhaps 10 years with minimal exposure to a medical waste incinerator; and now re-exposed to a stream of dioxins, furans, PCB's and dioxin-like organo-chlorines and metals such as mercury, nickel, chromium, lead and cadmium

  • Is the Canada Wide Standard of 80ng dioxin/m3 promulgated by the CCME protective for this population?
  • If the CWS for dioxin release is not protective what is the acceptable risk-based release in order that the population exposed under the Sydney Scenario have no further risk from adverse and biochemical effects?
  • What is an appropriate UF in order to establish an appropriate TDI for this population taking into account the distribution of age, gender, BMI in Cape Breton all compared to the population where the TDI was originally established?
  • What adverse affects can be expected from the additional exposure to dioxins apart from diabetes and heart disease?
  • The provisional Tolerable Weekly Intake (PTWI) of Methyl Mercury is 3.3 pg/kg-bw/wk. The PTWI of inorganic mercury 5pg/kg-bw/wk. is the CWS for mercury protective for the population from mercury and protective for the population from methyl mercury that will form in the waters from mercury?
  • Will the formation of methyl mercury appear within five years of commencement of operation of the proposed incinerator?
  • If the CWS for mercury is not protective what is an appropriate risk-based release for mercury from the proposed incinerator in oder that the population will have no further risk from mercury or methyl mercury?


[Original signed by James Argo]

James Argo Ph.D. (Cintab)
IntrAmericaS Centre for Environment and Health
P.O. Box 101
Wolfe Island, Ontario
613-385-1831 eve
813-385-1832 fax

[Original signed by Mary Ruth MacLellan]

Mary Ruth MacLellan, Chair
Save Our Health Care Committee
391 Phalen Road
Glace Bay, Nova Scotia
B1A 3B6

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Minister's Response: Environment Canada

August 3, 2006

Ms. Mary Ruth MacLellan
Cape Breton Save our Health Care Committee
391 Phalen Road
Glace Bay, Nova Scotia
B1A 3B6

Dear Ms. MacLellan:

I am writing to provide Environment Canada's and the Canadian Environmental Assessment Agency's (the Agency) response to petition 140B to the Commissioner of the Environment and Sustainable Development concerning the proposed Sydney Tar Ponds and Coke Ovens Sites remediation project. Your petition was received in the Department on April 4.

As you are aware, the former Minister of the Environment determined that a review panel was the most appropriate level of environmental assessment for the proposed remediation project. Subsequent to this decision, a joint federal-provincial review panel was established which provides for ample opportunities for public involvement. The Agency provides support to that panel. I am aware that the Cape Breton Save Our Health Care Committee was a full participant in the review panel process, including the public hearings which were completed on May 18.

As a responsible authority, Environment Canada identified issues, asked questions, and made recommendations to the review panel. As well, Environment Canada dedicated the necessary resources to thoroughly review the documentation that the proponent provided. Environment Canada's written submission, oral presentation, and various recommendations to the review panel were based on this review.

Environment Canada identified several issues that need to be addressed to the satisfaction of the appropriate government departments prior to the issuance of regulatory approvals and authorizations, and therefore prior to the construction of the project. The recommendations that Environment Canada put forward to the review panel were made to address the issues, and to ensure that the project will be capable of meeting regulatory requirements. All of the documents produced as part of the review process are available through the Canadian Environmental Assessment Registry at

Many of the issues raised by the Cape Breton Save Our Health Care Committee in petition 140B were brought forward during the review of the Environmental Impact Statement and during public hearings. I am presently reviewing the report.

Yours sincerely,

[Original signed by Rona Ambrose, Minister of the Environment]

Rona Ambrose


The Honourable Tony Clement, P.C., M.P.
Ms. Johanne Gelinas, Commissioner of the Environment and Sustainable Development of Canada

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Minister's Response: Health Canada

29 July 2006

Ms. Mary Ruth MacLellan
Save Our Health Care Committee
391 Phalen Road
Glace Bay, Nova Scotia
B1A 3B6

James Argo, Ph.D.
IntraAmericas Centre for Environment and Health
P.O. Box 101
Wolfe Island, Ontario
K0H 2Y0

Dear Ms. MacLellan and Dr. Argo:

I am writing in response to Environmental Petition 140B, which was submitted to the Auditor General of Canada in March of this year. The petition seeks a response from Health Canada relative to a number of issues concerning Sydney, Nova Scotia. Although many of these issues are multi-jurisdictional or do not fall solely within the mandate of Health Canada, I will respond from the federal health perspective.

Health Canada fully supports the efforts of the Canadian Council of Ministers of the Environment (CCME) and the standards developed through this cooperative process. As you may be aware, provinces, territories and the federal government have used the CCME forum to undertake joint initiatives to address major environmental issues in Canada for more than a dozen years. Over the last several years, the majority of CCME activity has focused on actions to deliver on the objectives of the Canada-wide Accord of Environmental Harmonization, signed in January 1998. Under this harmonization accord, governments are implementing sub-agreements on Canada-wide standards and environmental assessments by using their existing authorities in a coordinated manner to protect the health of Canadians.

A number of the specific concerns cited in Petition 140B are in reference to the Sydney Tar Ponds Remediation Project, which has recently undergone a full panel review. This transparent process allowed for the voicing of many opinions, including those of the Save Our Health Care Committee, on a wide variety of topics related to the project. Health Canada participated in this process as an expert department and expressed its opinions and concerns in accordance with panel procedures. As a report was released on July 13, 2006, governments are now conducting a thorough review and will provide an appropriate response through the formal Environmental Assessment process.

You may wish to contact the Cape Breton District Health Authority and the Nova Scotia Department of Health Promotions and Protection concerning the demographics and population health of this specific geographical area. These agencies would be better suited to provide you with the information you are seeking. You may write to the Cape Breton District Health Authority at 1482 George Street, Sydney, Nova Scotia B1P 1P3, or contact them through their website at The Department of Health Promotion and Protection can be reached at P.O. Box 487, 1800 Argyle Street, Halifax, Nova Scotia B3J 2R7, or at

Thank you for taking the time to raise these important issues and for expressing interest in environmental stewardship on behalf of your community organization.

Yours sincerely,

[Original signed by Tony Clement, Minister of Health and the Minister for the Federal Economic Development Initiative for Northern Ontario]

Tony Clement


Ms. Johanne Gélinas
The Honourable Rona Ambrose, P.C., M.P.