Rene (Ray) Matthey, 1923 - 2003
(This page is dedicated to the late Ray Matthey who passed away on November 27, 2003 in Ottawa. He was the founder of the Saunders-Matthey Foundation for cancer research. He wondered why hundreds of millions of dollars spent on cancer research has not produced a reduction in cancer incidence. Mr. Matthey felt that more research on environmental pollutants that cause cancer is needed.) from a Globe and Mail obituary, March 31, 2004
Pollution and Cancer: Stunning and Striking? December 1999
A. C. Goddard-Hill.
In the late sixties three Ontario biologists, Drs. Donald Chant, Bryce Kendrick and David Suzuki founded the environmental public interest group Pollution Probe. These men taught us to think about the effect of environmental factors on biological systems. Since then in the field of human biology cigarette smoking has been accepted as the cause of about one quarter of human cancers. This example of chemical carcinogenesis has led many to wonder what other human cancers are related to chemical exposures. In the last decade evidence around this question has been accumulating in the general and specialist medical literature. One review found almost five hundred articles relating environmental pollution to human health in the last seven years editions of five general medical journals.
Now, thirty years later, Pollution Probe is alive and well but public health officials have yet to board the environmental health train. For example environmental carcinogens have been absent from the mandate of the prevention unit of the provincial cancer control agency in Ontario.
Environmental and occupational carcinogens include industrial effluents, household chemical products, pesticides and radionuclides.
There are approximately 70,000 chemicals in use in modern industrialized countries, 3000 of these in high volume use as defined by the U.S. EPA. Some 667 of these compounds are known carcinogens and of those 84 are in high volume use. The release of these compounds into the environment raises questions about implications for human health. However such questions are difficult to answer as in the overwhelming majority of cases the chemicals of concern have never been adequately if at all tested for chronic toxic or carcinogenic effects. In Canada some 23,000 chemicals are approved for use and of these a meagre 31 have completed toxicity testing. There are currently about 200,000 tonnes of voluntarily reported releases of toxic chemicals into the Canadian environment annually and of these 13,000 tonnes are suspected or known carcinogens. 50,000 tonnes of pesticides are used each year in Canada. One pound of dioxins are released.
One consequence of this pollution is that breast milk in Canada contained 25 times the safe level of dioxin (compared to the WHO standard) when last assayed in 1992. Since then there has been no further Canadian data on this primal matter of mothers milk. However in the U.K. the World Wildlife Fund recently reported that British breast milk contains forty times the safe level of dioxin. This is uncertain nourishment for the next generation.
Another consequence of environmental pollution is that 200 synthetic chemicals are now measurable in the human body. The organic chemicals are of particular interest. These include the non chlorinated varieties such as benzene and benzo(a)pyrene, and the chlorinated organics which number some 11,000 and which include vinyl chloride, trichlorethylene, pcbs and dioxins. Chlorinated organic chemicals, the so-called persistent toxic substances, were first produced on an industrial scale in the forties. The bad news about them began arriving in the sixties when Rachel Carson collared the chlorinated pesticides. The following decades brought further revelatory waves of negative news about the pcbs and cfcs in the seventies, the dioxins and furans in the eighties and the APEs, bisphenols and pthalates in the nineties. Most of these compounds have their origins in the chlorine chemical industry. They include byproducts from the use of chlorine as a bleaching agent by the pulp and paper industry, PVC plastics production, pesticides, fugitive dichloromethane from the pharmaceutical industry, various intermediates, refrigerants, and solvents. They are also produced by the hundreds through the incineration of chlorinated (PVC) plastic waste.
Researchers and activists interested in chemicals have made much of their non-cancer health effects including perturbations of human sexuality, brain injury, and immune dysfunction. However lay epidemiologists, a.k.a. the general public, still regard these effects with a certain comedic skepticism. When we look down our collective pants or gaze at the video screen the sexual vigour of the human race is hardly in question. (Indeed the idea that environmental pollutants could reduce the fertility of our prolific species has a certain attraction.) When we observe the computer industrys ingenuity in propagating the global neural network the collective brain power of our race seems assured.
By contrast cancer remains a dread disease about which the public has a serious concern. Citizens increasingly link chemicals with cancer.
There is quite a spectrum of opinion with respect to the cause of cancer. At one end is for example the Canadian Cancer Society which concluded that the main culprit is the aging of the population and that toxics and bad habits are not the cause. By contrast in Ontario the provincial cancer agency is concerned about bad habits and lifestyles while across the street at the Ontario Ministry of Health their Statement of Environmental Values calls for the elimination of pollutants and carcinogens as causative agents of cancer. (An independent environmental commissioner found there has been little action predicated on these sentiments.) Similarly the federal environment department has called for a reduction in public exposure to toxics and carcinogens through decreased industrial discharges of compounds such as benzene, lead, mercury, dioxin and chromium. (The government plans to achieve that goal by voluntary limits on pollution which industry itself has said are unlikely to be effective.) At the other end of the spectrum Epstein speaks darkly of the cancer establishment and their propensity to ignore the effluvia of industry which he says accounts for the majority of human cancers.
The general medical literature has had much to say about toxics. The recurring theme is that carcinogens cause cancer. Dixon identified the disease as one in which genes are triggered into mischief by carcinogens. Miller recalled the long lag time between exposure in early life and the appearance of the disease decades later. Kessler focused on the overexposure of children to carcinogens and Davis expanded the envelope by noting critical periods of exposure during pregnancy and adolescence when timing can be more important than dose. Rassool returned to the interaction between carcinogens and genes and hinted at the gradient of differential susceptibility and resistance to carcinogens found in human populations as a function of complex genetic factors.
What has the literature said about common cancers and carcinogens? Tang identified the damage to tumour suppressor gene DNA from exposure to benzo(a)pyrene in cigarette smoke, suggesting one mechanism of carcinogenesis. The International Joint Commission of the Great Lakes revealed that this compound has sources other than cigarette smoke when it identified benzo(a)pyrene as one of eleven critical contaminants found throughout the Great Lakes basin. This polyaromatic hydrocarbon is a legacy of historical industrial activity in the area. A study of workers exposed occupationally to dioxins confirmed the carcinogenic nature of these compounds when higher rates of lung and other cancers were found in the workers. Canadian and U.S research found higher incidences of bowel cancers in populations drinking chlorinated water over decades attributable to trihalomethane content. Great interest in the relationship between organochloride exposures and the rising incidence of breast cancer was reported. One group found that women so exposed happened to achieve some degree of protection from that scourge by breast feeding their infants. Thus the fundamental human gesture of lactation apparently flushes toxics from the maternal breast. The recipient is the newborn breast feeding infant.
Next the uncommon and rare cancers. Some of these increased by stunning increments of 1 4% per year. Would these tumours be uncommon and rare today if they had sustained such increases over long intervals of time or is this only a recent phenomenon? Epidemiologic trends in non Hodgkins Lymphoma and testicular cancer may prove more instructive in teaching the lessons of environmental epidemiology than have the common cancers. In these uncommon tumours the effects of chemical exposures may be less confounded by other factors than are the common cancers. Non Hodgkins Lymphoma and testicular cancers rose at 2 4 % per year and pcbs and pesticides proved popular in the literature as putative causes. Melanomas doubled in the southern hemisphere due to chlorofluorocarbon destruction of protective ozone. Brain cancer in the elderly doubled due in part to occupational and nonoccupational chemical exposures.
The shifting epidemiology of the childhood cancers has been striking. Their overall incidence in Canada and the U.S. increased twenty per cent in twenty years as did the incidence of the leukemia subgroup. One researcher focused on leukemia and prenatal and infant exposures to EMF radiation, and the big increase in childhood brain tumors seen at an Ontario childrens hospital was attributed in part to industrial and other environmental exposures. A review paper listed 185 references variously making the connection between childhood cancer and environmental toxics. A British study related the occurrence of childhood cancer to proximity to hazardous industrial sites.
These findings suggest that Barkers hypotheses on programming of non-cancer diseases by environmental exposures during the prenatal and infant stages could also apply to cancers.
Environmental politics in the province of Ontario was heated throughout this decade. The International Joint Commission of the Great Lakes with the support of the American Public Health Association began the decades debate with their 1992 report based on human health considerations. The binational commission called for elimination of PVC plastic production, elimination of chlorine use by the pulp and paper industry, and elimination of waste incineration. However despite those recommendations PVC plastic production continued apace with a sixty percent increase recorded by the end of the decade. For their part and in response the pulp and paper industry invented creative solutions to the problem of disposal of dioxin-contaminated waste pulp liquor rather than eliminating chlorine use from the process. They cleverly marketed the waste material as a dust suppressant for use on country roads and persuaded local governments to spread this toxic stew around huge areas of provincial watersheds. The Times Beach disaster in rural Missouri of two decades earlier was apparently forgotten.
Incineration of municipal, medical and hazardous waste was identified by the Canadian and U.S. governments as a major source of dioxins and metals entering the environment. However after a brief respite hearings in Ontario are now under way again for the construction of new incinerators. Proposed sitings are usually in rural and economically depressed areas of the province, a social phenomenon portrayed by activists as environmental injustice. British and American studies have both found higher rates of cancer in the vicinity of such facilities.
What happened to environmental research during the decade? Paradoxically the number of articles appearing in the general medical literature went into steep decline starting in 1996 after increasing interest registered in the first half of the decade. This decline began after the collapse of government environmental program funding in various jurisdictions. For example the budget of the Ontario Ministry of Environment fell by half in the second half of the decade. Governments became more and more uninterested in environmental health. There was little data on toxics and health as the century closed because there was no money to analyse and research. Academic research agendas were determined to a large extent by generous funding for cancer drug treatment trials by the large pharmaceutical companies. Corporations showed little interest in funding environmental research.
The problems in toxics and cancer are these. First, there is a research bias away from prevention in general and away from environmental health research in particular. Secondly, in the presence of plenty of existing evidence there is a lack of leadership in cancer prevention by pollution prevention in the Province of Ontario and presumably in other jurisdictions around the globe.
However this has not occurred in the complete absence of good advice. For example in 1995 Griers Task Force for the Primary Prevention of Cancer recommended that "government should establish timetables to sunset the use of chlorine-containing compounds as industrial feedstocks and examine the means of reducing or eliminating other uses of chlorine, bearing in mind the priority to ban substances established as carcinogens. We urge action now." Occupational and environmental carcinogens are a significant public health issue. They need to be put on the public agenda.
Dr. Ken Shumak, President, Cancer Care Ontario,
620 University Avenue
Toronto, Ontario M5G 2L7.
Dear Dr. Shumak,
Thankyou very much for meeting with our citizens group in July. We made the case for the inclusion of Environmental and Occupational Carcinogens in the mandate of the Cancer Care Ontario Prevention program .
The CCO Strategic Plan has now been approved by the Board of Directors
(November 25 1999). I am pleased to note that you have acknowledged the issues which we raised. Excerpted here are some statements from your document.
"Occupational cancer is an important concern. CCO will become involved
in preventing occupational cancers, beginning with improved surveillance. CCO will create a collaborative group of stakeholders and experts to make recommendations regarding the most effective means of surveillance of occupational cancer. A variety of surveillance strategies have been proposed, including routine reporting of occupation with incident cancer cases. The utility of these strategies must be assessed and the effective approaches incorporated into our cancer surveillance. Environmental carcinogens are a source of concern and controversy. CCO will identify opportunities for evidence-based interventions in this field."
With respect to evidence about environmental carcinogens, our province
and country should prove to be a real mother lode of opportunity for your epidemiologists.
For example at one end of the province we have recently learned that the Sarnia hazardous waste landfill is leaking into local ground water, while at the other end approval for the operation of a hazardous waste incinerator of doubtful efficiency has just been granted in Cornwall. At the local level the Ontario Ministry Environment last week confirmed that medical waste incinerators currently operate in communities in Ontario with no pollution controls or requirements for monitoring of emissions whatsoever. At the federal level the National Pollutant Release Inventory has recently documented a large increase in chemical pollutants released in Canada for the last reporting year of l997 (Ontario now having attained the No. 2 polluter status on the continent) and facilities in Swan Hills, Alberta and Chalk River Ontario are now preparing to receive international sources of hazardous and nuclear waste.
Appended to this letter is a review entitled "Pollution and Cancer: Stunning and Striking?".
Can you speculate as to when CCO will start to "identify opportunities for evidence-based intervention in the field of environmental carcinogens?"
Best wishes for the new century.
A. C. Goddard-Hill
Sun, 12 Dec 1999 10:49:49 -0500
Dear Dr. Goddard-Hill,
Thank you for your email. Now that CCO's strategic plan has been approved by our Board, each of our divisions will be developing implementation plans. Once this important next step is taken, it will be possible to answer your question as to when CCO will begin to actively "identify opportunities for evidence-based intervention in the field of environmental carcinogens".
Thank you for your good wishes for the new century. My very best wishes to you as well.
December 8, 1999 (email)
Dear Dr. Goddard-Hill
Thankyou for you letter and copy of your presentation entitled "Chemical Pollution and Human Health in the Bay of Quinte Region". I am very appreciative of your continuing interest in cancer prevention.
I have asked Dr. Schabas for his appraisal of the Health Canada study to which you refer.
I am pleased that Dr. Noseworthy will be monitoring local cancer rates. Cancer surveillance is a critical component of cancer control. I am sure that the Surveillance Unit of CCO's Division of Preventive Oncology will be able to assist her.
Thankyou again for your interest.
Ken Shumak President and CEO, Cancer Care Ontario
cc. Helen Cooper
Dr. A. Lynne Noseworthy
Medical Officer of Health
Hastings Prince Edward Counties Health Unit
Belleville, Ontario K8P 4P1
March 24, 2000
Dear Dr. Goddard-Hill
Re: your letter of November 15, 1999
Thankyou for you letter of November 15, 1999, and its accompanying information.
I will respond to the two questions posed in your letter.
#1. Request for copies of reports on toxic sites in Hastings & Prince Edward Counties Health Unit.
Ontario boards of health are not mandated to produce reports on toxic sites within their jurisdictions; accordingly, we have not produced such reports for our area. You may wish to refer your question to Mr. Brian Ward, MoE, Kingston.
#2. Response of the Health Unit to the Health Canada Bay of Quinte Study.
The Health Unit received the document entitled Great Lakes Health Effects Program, Bay of Quinte Area of Concern: Health Data and Statistics for the Population of the Region (1986-1992), A technical Report for the RAP Community" on October 15, 1999. As you are probably
aware, the report, along with 16 others was prepared by Health Canada's Great Lakes Health Effects Program.
My staff and I have now had an opportunity to review the report. In addition, we have discussed the report with several of our colleagues.
We also arranged for Dr. Yang Mao and Mr. Douglas Haines, of Health Canada, who were involved in the production of the reports, to attend a recent meeting of the Eastern Ontario Medical Officers of Health, in
order to discuss the reports.
The Bay of Quinte Area of Concern Report analyzed data for: numerous health outcomes as causes of death and hospitalization; many selected cancers as causes of disease and death; and a number of selected congenital anomalies as birth outcomes and causes of death. These data
were analyzed by age and sex, for the populations of over 30 municipalities and 3 Indian Reserves within the geographic areas of 4 different Health Units. (named) The report was created by Health Canada with no input from any of the 4 health units involved.
Because of the breadth of the geographic area and the number of outcomes that were included in the report, the specific applicability of the findings to our Health Unit is difficult to determine. We will continue to review the findings and utilize the report as one of the many data sources at our disposal.
Some of the issues which we have identified from our own analysis of data available to the Health Unit, and which require ongoing review for Hastings and Prince Edwards Counties include the following:
*both males and females in Hastings and Prince Edward Counties have higher incidence and mortality ratios for lung cancer, and a higher risk of dying from ischemic heart disease, motor vehicle collisions and from all injuries combined, as compared with the province as a whole.
*at 29.8%, the percent of smokers in Hastings and Prince Edward Counties was 10.8% higher than the Ontario figure of 26.9% in 1996/97.
Under Section 7 of the Health Protection and Promotion Act, Ontario boards of health are mandated to provide programs and services as outlined in guidelines published by the Minister of Health. These programs and services include those which address major causes of
morbidity and mortality in our area, including lung disease, ischemic heart disease and injuries. As well, boards of health are required to assess the community health status in their health units.
You may wish to contact the authors of the report and ask them for their interpretation of the report. You can direct your queries to Mr. Douglas Haines, Health Canada. (address given)
A. Lynn Noseworthy, MD, MHSc, FRCPC,
Medical Officer of Health, Hastings Prince Edward County
cc. Brian Ward, Douglas Haines, Ying Mao
Subject: Letter from MoH, Hastings Prince Edward (email)
Date: Sun, 02 Apr 2000 19:40:10 -0400
Dr. Ken Shumak
CEO, Cancer Care Ontario
Dear Dr. Shumak,
Thankyou for your reply of December 8, 1999.
At that time you indicated that your Prevention unit would be responding to the Health Canada Studies. Can you give some indication of when that will occur?
Appended is Dr. Noseworthy's response. She seems to step around the question completely. (Indeed when her epidemiologist gave a presentation to Quinte Watershed Cleanup Inc recently on Cancer rates in Hastings Prince Edward it was apparent that he was completely unaware of the existence of local toxic sites.) Dr. Noseworthy's point about not being required by the HPP Act to report on local toxic sites is interesting.
When I was Acting MoH at the H PE Health Unit in 1991, monitoring of local toxic sites was clearly mandated by the province under the Environmental Health program of the HPP Act.
Also appended is correspondence with the Secretary of the Cabinet on a regional Environmental Health issue.
April 24, 2000
Dr. A. Lynne Noseworthy
Medical Officer of Health
Hastings Prince Edward Counties Health Unit
Belleville, Ontario K8P 4P1
Re: Toxic sites, Bay of Quinte
Dear Dr. Noseworthy,
Thank you very much for your letter of March 24, 2000.
I was little surprised by your assertion that "Ontario boards of health are not mandated to produce reports on toxic sites within their jurisdictions: accordingly, we have not produced such reports for our area."
While the previous version of the mandatory health program guidelines based on the Health Protection and Promotion Act were much more specific on this point, the current version is also quite clear. In the section entitled "Health Hazard Investigation", the prescribed goal is "to prevent or reduce adverse health outcomes resulting from exposure to health hazards..including biological, physical and chemical agents, natural or manmade."
As you know, the Bay of Quinte has been designated as an "Area of Concern" by the International Joint Commission due to a number of factors including chemical pollution. Quinte Watershed Cleanup Inc is a public advisory group of citizens trying to facilitate the Remedial Action Plan which would see the Bay returned to a less polluted state. Health Canada and your own Health Unit have now confirmed higher rates of certain diseases in the area. Although as you point out it is "difficult to determine" the relationship between chemical environmental pollution and human health I wonder to what extent the Medical Officer of Health is engaged in addressing this question.
Perhaps the answer was suggested by a recent presentation given by Brian Laundry, our epidemiologist. While he gave an excellent discussion on Moira River cancer epidemiology he seemed to be largely unaware of the dozen or so other sites of chemical pollution in the Bay of Quinte region identified by Quinte Watershed Cleanup.
As a practical matter perhaps you could address the Meyers Pier Park site as an example of what we are asking about. As you may be aware a Risk Assessment done in the last three years by one consultant and confirmed by another made the highly unusual finding of significant risk of certain cancer and non cancer diseases to the community from the site as it currently exists.
To my knowledge the only public comment on this finding made to date was that of a city official in November 1998. His analysis was that the risk assessment showed the area was "not unsafe" for use by the public. Did the Health Unit make an analysis of the significance of the Risk Assessment findings, and if so what was your analysis? Do you concur that the Risk Assessment shows that the site is "not unsafe"?
cc. Chairman, Hastings-Prince Edward Counties Board of Health
Dr. Ken Shumak, CEO, Cancer Care Ontario
Dr. Lynn Noseworthy
MoH, Hastings Prince Edward Health Unit
June 7, 2000
Dr. Ken Shumak
President and Chief Executive Officer
Cancer Care Ontario, Provincial Office
Toronto, Ontario M5G 2L7
Dear Dr. Shumak,
Thank you very much for your letter of April 28 in which you responded to my question about the Health Canada studies, and for your appearance at the Cancer Prevention in the 21st Century, and Environmental Pollution meeting held at the U of T on May 2.
Coincidentally I did speak to Dr. Holowaty about the Health Canada Areas of Concern studies at the meeting and he was very candid in expressing his opinion about their value.
I certainly appreciated your public acknowledgement at the U of T meeting of the issue of environmental and occupational carcinogens as a legitimate component of the mandate of the Prevention Unit of CCO and as well your continuing call for public participation in the formulation of prevention policy from that mandate. (Enclosed is an account of the May 2000 report of the North American Commission for Environmental Cooperation which indicates that for the last reporting year of 1997, carcinogen loading of the North American environment proceeded apace: "releases directly from industrial sites into air, land and water totaled about 850 million kilograms in 1997. Roughly 15 percent were carcinogens, most of which went into the air.")
The reason that I approached Dr. Holowaty was to express some disappointment with the program content of the U of T meeting. I reminded him that I had identified the issues of concern at the meeting which was held at your office last summer. His reply was that he had found my presentation "confused" and "completely unhelpful" to CCO in your policy formulation deliberations. That being the case I apologize. In an effort to be more clear I have appended here a list of subjects, some taken from my presentation last summer, which I believe might be worthy of consideration when next the CCO holds a public session on Environmental Pollution and Cancer Prevention.
As it was we did hear a very interesting presentation from Dr. Will King on potentially carcinogenic water chlorination by-products, followed by a debate in which two of the province's leading environmental activists found themselves in the unenviable position of defending a motion for the elimination of chlorination as a method of water purification in Ontario. I suspect that this is an argument that they would not normally have advanced as in my experience this is a non-issue amongst environmental activists.
Recent events in the province illustrate the reason. The audience, largely made up of people from the public health community, must have wondered from what planet these activists had travelled.
It was interesting to learn at the meeting that in the Ontario Blueprint for Cancer Prevention which you have recently released the figure quoted for the percentage of cancer which occurs in Ontario as a consequence of occupational exposure has been reduced from nine to five percent, the latter figure having been derived, as the moderator acknowledged, from a Harvard study. One of the meeting participants pointed out that the Harvard School of Public Health is heavily subsidized by major American industrial interests, a number of which she identified. (A copy of this list is enclosed.) I wonder whether it is appropriate to be using such research as a source of information for the Province of Ontario.
Dr. Holowaty did make one helpful suggestion in my conversation with him and I would like to ask you to implement that suggestion. In Belleville we have a hazardous waste site known as the Meyer's Pier Park Marina which is heavily contaminated with mono and polyaromatic Hydrocarbons and carcinogenic metals. A risk assessment has been completed in the last two years by GPEC International Consultants. It demonstrates a significant risk posed to the community of certain kinds as cancers as well as other diseases. The results of this risk assessment were, at the request of the City, independently reviewed and confirmed by another risk assessor, Dr. Sam Kacew of the University of Ottawa Medical School. The local public health unit has replied, in response to my request for interpretation, that they are not responsible for reporting on toxic waste sites. When I explained this to Dr. Holowaty he noted that he would be available to assist the Health Unit, or alternatively to make a direct analysis, of the implications of the Risk Assessment for our community. (A summary of the Meyer's Pier Park information is available on my website, )
I understand that the staff of the Preventive Oncology department have recently acquired some experience in the matter of cancer risks posed by PAH contaminated sites through their analysis of a (much larger) site in Nova Scotia. I would therefore be grateful if you would ask Dr. Holowaty to proceed. You will be receiving a letter of support for this request from Quinte Watershed Cleanup Inc, a local public interest group which represents various sectors of our community and of which I am a member.
Again, thank you for your continuing interest. I know that there are many demands on your time.
cc. Dr. John Garcia
Suggested Topics for Cancer Prevention in the 21st century and Environmental Pollution:
- diesel exhaust and other air toxics and their relationship to cancer
- pesticides and their relationship to cancer, especially childhood cancer (e.g consideration of the Pesticides control initiative of the Toronto Board of Health, March, 2000)
- possible relationships between environmental carcinogens and breast cancer
- ecotoxicity and the body burden of persistent organic pollutants-what are the implications for cancer?
- Health Canada 1999 reports on 19 Areas of Concern around the Great Lakes: industrial pollution and effects on human health
- Carcinogen loading in the North American environment: data provided annually by the US Toxics Release Inventory and Canadian National Pollution Release Inventory, through the Commission for Environmental Cooperation
- International Joint Commission (Science Advisory Board ) recommendations (from the last decade) for virtual elimination of Class I contaminants (chlorinated organic chemicals) from industrial discharges out of consideration for human health
- Canadian Breast Milk Contaminant Surveys (1982, 1986, 1992) in which dioxin levels in Canadian breast milk and infant formulas were tracked: implications for human health?
- Great Lakes Health Effects Program reports, Health Canada: carcinogenesis and chemical contaminants in the Great Lakes Basin
- Canadian Dioxin Inventory, 1999, implications for human health
- U S. EPA re-assessment of dioxin as a human carcinogen, formerly estimated to cause 1:1000 human cancers, now re-estimated to cause 1:100 human cancers ("Integrated Summary and Risk Characterization, US EPA, May 1, 2000)
- U S. National Toxicology Program 9th Report on Carcinogens, May 15, 2000: TCDD as a human carcinogen
- etc, etc
Cancer Care Ontario
620 University Avenue
Toronto, Ontario M5G 2L7
e mail: email@example.com
June 29, 2000
Dr. A. C. Goddard-Hill
General and Family Physician
450 Dundas Street East
Dear Dr. Goddard-Hill,
Thank you for you letter of June 7. I appreciate your continue interest in cancer prevention in Ontario.
I am glad you found the debate about the chlorination of drinking water at the recent Preventive Oncology Seminar so stimulating. The purpose of these debates is to tackle controversial issues in a collegial setting. Certainly, in light of the Walkerton tragedy, your view that no reasonable person could oppose chlorination of drinking water seems hard to argue with.
Dr. Holowaty and the Surveillance of the Division of Preventive Oncology are prepared to assist local medical officers of health in their investigation of local cancer risks, when this assistance is requested. In most cases, local medical officers of health are fully capable of conducting these analyses without our assistance. We would be willing to provide advice regarding the Meyer's Pier Park Marina if and when the local medical officer of health requests it.
Thankyou again for your interest in Cancer Care Ontario.
Ken Shumak, MD, FRCPC
President and CEO
Cancer Care Ontario