CHAPTER TWO Contents

2.1 INTRODUCTION

2.2 HEALTH

2.2.1 Methodologies for Community Health Assessment: Measuring Injury to Health

Scientific, Diplomatic and Political Responses to Great Lakes Pollution

Community Health and Areas of Concern

Health Effects in Canadian Areas of Concern: 17 Health Canada Reports

Mapping

Extended Narrative: Focus on Windsor

Further Statistical Analysis

Responses from the Medical Officers of Health

Availability of Health Data in the United States

Biochemical Epidemiology

Issues of Economic Costs of Disease and of Equity

Contrasting the Scientific Approach and the Public Health Approach

Conclusions

Research Needs

2.2.2 Protecting Human Health from Exposure to Contaminants in Great Lakes Fish

Introduction

Risk Assessment and Limitations

Risk Management

Risk Communication

2.3 WATER QUALITY ASSESSMENT AND REPORTING

2.3.1 Review of Annex 1 of the Great Lakes Water Quality Agreement

Introduction

A Proposal to the Commission

Background Report

Workshop

Findings and Recommendations

2.3.2 Review of Agreement

2.3.3 Nonpoint Sources of Pollution from Land-use Activities

Introduction

Insufficient Persuasive Evidence of the Effectiveness of Best Management Practices

Lack of Performance Standards

Economic Considerations

Inadequate Institutional Arrangements

2.3.4 Evaluation of SOLEC Indicators Relative to the GLWQA

Criteria

Review of SOLEC Indicators

Results

Discussion

2.3.5 Remedial Action Plan Assessment: Site Visits to the Niagara River
and St. Lawrence Areas of Concern

2.3.6 The Use of Atmospheric Modeling in Policy Development
and Using Models to Develop Air Toxics Reduction Strategies

Conclusions and Recommendations

Core Findings

Sources and Loadings

Modeling

Ambient Sampling

Source Control Initiatives

2.4 EMERGING ISSUES IN GREAT LAKES SCIENCE, RESEARCH AND POLICY

2.4.1 Application of a Methodological Framework and a Proposed Process
for Agreement Institutions in Addressing Emerging Issues in Great Lakes

Science, Research and Policy

2.4.2 Green Chemistry

2.4.3 Integrated Observation and Monitoring Network

2.5 ACTIVITIES AND MEETINGS OF THE SCIENCE ADVISORY BOARD
FOR THE 1999-2001 BIENNIAL CYCLE

2.6 BOARD AND WORK GROUP MEMBERSHIP FOR 1999-2001

2.7 REFERENCES

Appendices

I. List of Health Outcomes Selected by Health Canada on the Basis that They Might Be Linked to Pollution

II Mortality, Morbidity and Congenital Anomalies Rates (1986-1992) in the Windsor Area of Concern

Tables

1. SOLEC Evaluative Framework Developed by Clemson University Researchers

2. Ranking of Indicators Deemed as Excellent, Good and Moderate in Fulfilling Reporting Requirements
under the Agreement

3. 12 Principles of Green Chemistry

DISCLAIMER

Every attempt has been made to attribute the expert opinions and comments in this report and to clearly distinguish them from the advice of the Science Advisory Board to the International Joint Commission. While these views are important and relevant for the report, they do not necessarily represent the views of the board or the International Joint Commission.

2.1 INTRODUCTION

_U nder the Great Lakes Water Quality Agreement, the
Science Advisory Board (SAB) was established to
provide scientific advice to the International Joint Commission (IJC) and the Great Lakes Water Quality Board (WQB) and is responsible for developing recommendations on all matters related to research and the development of scientific knowledge pertinent to Great Lakes water quality. Such a broad mandate requires a multi-disciplinary approach and accordingly, members are appointed from each country by the IJC with expertise in the natural, physical and social sciences. Within the broad mandate of the board, there are several processes that determine what is to be done and which of the myriad problems or scientific issues are most salient in terms of water quality, and for consensus building to support SAB recommendations.

Major activities of the SAB are largely tied to the IJC's biennial cycle. Development of board priorities by the IJC is based on consultation with its boards at the beginning of each biennial cycle and with the public during the biennial Public Forum. The Commission assigns a lead role to each of the advisory groups, according to whether the question is one of policy, science or research. A sole priority topic was initially assigned to the SAB for the 1999-2001 biennial cycle titled Methodology for Assessing Community Health in Areas of Concern , building on the previous work of the board in human and community health (1992 workshop in Ann Arbor, Michigan titled Our Community, Our Health , IJC 1994) . Throughout the past decade, as a result of

significant investments by the United States and Canadian governments in Great Lakes environmental health research, there has been a new appreciation of the injury to human health from exposures to persistent toxic substances, particularly from the consumption of Great Lakes fish. Of particular concern are the irreversible changes in fetal developmental processes as a result of maternal consumption of Great Lakes fish prior to and during pregnancy. The challenge for researchers, managers and policy makers is to determine the relevance of the effects identified by the scientific studies and the extent of injury occurring in critical subpopulations in communities, particularly in Areas of Concern (AOCs).

During the preparation of its Tenth Biennial Report on Great Lakes Water Quality, and in assessing the threat to human health from persistent toxic substances during its review of Annex 12, the IJC noted its serious concerns about this injury to human health from exposures to contaminants in Great Lakes fish. Generally, the policy response of governments is to issue fish consumption advisories. As stated in the report, this can only be considered an interim solution pending restoration of the chemical integrity of the ecosystem. Further, Commissioners requested additional advice on the adequacy of the advisories during the 1999-2001 biennial cycle and thus an additional human health related assignment was referred to the board.

A third major activity of the SAB, the review of Annex 1 of the Great Lakes Water Quality Agreement, evolved from the preliminary assessment of Lake Michigan Mass Balance data, by the SAB's Work Group on Parties Implementation. The original intent of this activity, to compare Lake Michigan Mass Balance data with Annex 1 Specific Objectives, led the work group to address broader issues related to the current relevance of Annex 1 to the Agreement, and its usefulness as a framework for reporting the status of Great Lakes water quality. The Commission accepted the advice of the board to fund further study, and in September 2000, this initiative began.

Several other important scientific issues were identified by the board and addressed with the assistance of student teams from Clemson University on the review of the State of the Lakes Ecosystem Conference ( SOLEC ), and from the University of Guelph of the review of Nonpoint Sources of Pollution from Land-use Activities .

The SAB also collaborated with the International Air Quality Advisory Board (IAQAB) on Atmospheric Deposition Modeling to Develop Control Strategies ; with the Water Quality Board on the Review of the Great Lakes Binational Toxics Strategy; and with the Council of Great Lakes Research Managers on the Application of a Methodological Framework and a Proposed Process for Agreement Institutions in Addressing Emerging Issues in Great Lakes.

The board completed a thorough review of its own internal processes for fulfilling its role under the Agreement, and developed Procedural Guidelines encompassing its administrative processes and work planning, the conduct of board workshops and the preparation of the Biennial Report on the Priorities and Progress under the Great Lakes Water Quality Agreement.

During this biennial reporting cycle, the SAB held two public meetings: at the IJC Biennial Meeting in Milwaukee, Wisconsin, held September 1999 (#115) and during the IJC status assessment of the Niagara River AOC, held in Niagara Falls in November 2000 (#120). Both meetings reflect the ongoing practice of the board to encourage public involvement and interaction with the board.

Given the ease of electronic communication with the Internet, there are greater opportunities than ever for interested citizens to be aware of their Great Lakes science heritage and to benefit from its discoveries in terms of societal change. Scientific knowledge, however exciting, is necessary but not sufficient as a sole basis for actions, as it must be applied wisely by decision makers, and their actions must receive public support, in order for progress under the Agreement to be sustained. Great Lakes citizens are encouraged to follow the board activities and advice by visiting their web site at the IJC home page at http://www.ijc.org/rel/boards/sab/index.html or to contact the board secretary Mr. Peter Boyer at boyerp@ijc.windsor.org for further information.

Finally, the board would like to acknowledge the efforts of all of the non-board contributors to the report, many of whom participated as invited experts at board meetings, industry tours, workshops and work group meetings. They include: Annette Ashizawa, Seth Ausubel, Thomas Baldini, Thomas Barnard, Michael Basile, Judy Beck, Mary Lynn Becker, Matthew Becker, Ryan Bodanyi, Ken Bondy, Barry Boyer, Jim Brophy, Jean Burton, Tanya Cabala, Michael Campana, Richard Carrier, Alice Chamberlin, Mathew Child, Theo Colborn, George Costaris, James Cowden, Joseph DePinto, Krista Devine, Jim Drummond, Abdel El-Shaarawi, Rose Ellison, Thomas Emery, Rick Esterline, John Eyles, Sharon Fedman, Ralph Ferguson, Joel Fisher, Irene Gauthier, Matt Hare, Lucy Harrison, Jim Hartnett, Maureen Healey, John Heatley, Allen Heimann, Henry Henderson, Adam Hess, Paul Horvatin, Robert Huggett, Irene Ilia, John Jackson, Lin Kaatz Chary, Neil Kagan, Rimas Kalinauskas, Wilfried

Karmaus, Margaret Keith, Elaine Kennedy, Daniel King, David Kohoko, Horace Krever, George Kuper, Wendy Larson, Kathleen Law, Mike Lawson, Michael Leffler, Matthew Longnecker, Kim Lund, Kevin Lynch, Yang Mao, John Marsden, Barbara McElgunn, Errol Meddinger, Russell Moll, Penelope Moskus, Tom Muir, Michael Murray, William Muszynski, Susan Nameth, Melanie Neilson, Scott Painter, Dale Phenicie, Christian Pupp, Lisa Richman, Kristina Riggle, Amy Roe, Rick Sherrard, Ted Schettler, Gary Silverman, Saulius Simoliunas, George Spira, Doug Spry, Helen Tryphonas, Michael Twiss, Raymond Vaughan, Marcia Valiante, John Vena, Anita Walker, Reuben Warren, Bernard Weiss, Brenda Wheat, Jim Whitaker, Marj Williams, Don Williams, Autumn Workman, Michael Zegarec and Donald Zelazny.

2.2 HEALTH

2.2.1 Methodologies for
Community Health Assessment: Measuring Injury to Health

Scientific, Diplomatic and Political Responses to Great Lakes Pollution

For more than 90 years, the International Joint Commission has been assisting the United States and Canadian governments in preventing and resolving potential disputes concerning the use of the boundary waters between the two countries, from coast to coast, under the Boundary Waters Treaty of 1909. Because the International Joint Commission is a diplomatic organization that undertakes its work by examining issues that are under dispute, it is not only a political, but also a scientific organization. Many of its responsibilities concern water use, diversions, allocations and other aspects of water quantity. But in the past 40 years, there has been a growing emphasis on water quality, particularly through the studies leading up to and subsequent to the signing of the 1972 Great Lakes Water Quality Agreement by the United States and Canada. The Agreement itself was both a political and scientific response to the widespread reports of deteriorating water quality in the Great Lakes basin.

At the core of the water quality aspects of the Boundary Waters Treaty is an agreement that the two governments would not pollute the boundary waters to the injury of health or property on the other side. However, in the preamble to the Great Lakes Water Quality Agreement there is an acknowledgment by the governments that this has happened and that the boundary waters in the Great Lakes basin have been polluted to the injury of health and property on the other side.

Initial priorities and programs were oriented to documenting and controlling eutrophication and developing and implementing common water quality objectives. But in the 1960s and through the 1970s, Great Lakes scientists began reporting observations of gross effects of persistent toxic substances on the reproduction and development of avian wildlife and ranch mink. These observations influenced the renegotiation of the 1978 Agreement. In the 29 years since the signing of the original Agreement, there have been enormous advances in documenting this injury to many species and taxa of wildlife and in formally demonstrating the causal links to specific pollutants. It has, however, proven more elusive to document the injury to human health from exposures to pollutants. Initial cohorts were established in the 1970s to investigate exposures from consumption of Great Lakes fish and the first cohort to examine possible effects on infant development from maternal consumption of Great Lakes fish contaminated with persistent toxic substances (Fein et al. 1983) was established in 1980. By the end of the 1980s, there was such a remarkable concordance between the developmental effects that had been observed in wildlife and those seen in studies of infants that it lead to the successful formulation of the unifying hypothesis of endocrine disruptors as a mechanistic explanatory principle linking effects on reproductive, developmental, neurological, endocrine and immune processes (Colborn and Clement, 1992).

These scientific findings were politically influential in both countries. In the late 1980s, Health Canada instituted its Great Lakes Health Effects Program, and in the early 1990s, the United States, through the amendments to the Clean Water Act, mandated the Agency for Toxic Substances and Disease Registry (ATSDR) to fund epidemiological research through the Critical Programs Act. The ATSDR studies confirmed that fish consumption is the major pathway of exposure to persistent toxic substances, such as dioxin, polychlorinated biphenyls and mercury, and identified at-risk populations, including Native Americans and other minorities, sport anglers, the elderly, males and females of reproductive age, and fetuses and infants of mothers consuming contaminated Great Lakes fish (Johnson et al. 1999). In human studies, increasing levels of sport fish consumption have been associated with difficulties in conception for Michigan sport fish anglers (Courval 1999). ATSDR has funded research and other community-based studies have the ability to influence policy and public health practice, thereby

directly enhancing the health status of vulnerable communities through identifying at risk groups consuming Great Lakes sport fish and by disseminating outreach materials alerting the public about safe fish consumption.

Community Health and Areas of Concern

In the mid-1980s, the IJC expressed concern about the recurrent reports from the governments of locations around the Great Lakes where water quality was out of compliance with water quality objectives, and particularly in relation to pollution by persistent toxic substances. These locations became known as Areas of Concern (AOC) and were intended for special programs to restore water quality through the development and implementation of Remedial Action Plans.

Health Canada, through its Great Lakes Health Effects Program, undertook a research project to investigate whether the incidence rates of diseases were different in the 17 Canadian AOCs compared with the rest of Ontario and to generate hypotheses about whether these differences might be related to exposures from local sources of pollutants. The data and statistics in the reports were compiled from a national databases kept by Statistics Canada for selected health endpoints that might be related to pollution and included mortality, morbidity as hospitalization, congenital anomalies and birth weights. There was considerable nervousness within Health Canada about releasing the 17 reports after comments were received from the local medical officers of health and from officials in Environment Canada and in the Ontario Ministry of Environment. But in November 1999, the reports were released to the public, just before the Great Lakes Health Effects Program was terminated on March 31, 2000.

Partly as a result of the availability of the Health Canada reports, the International Joint Commission directed the SAB to examine methodologies for assessing whether human health effects of pollution are occurring in communities in the Great Lakes basin. The SAB's Work Group on Ecosystem Health developed a workplan for a Workshop on Methodologies for Community Health Assessment for Areas of Concern , which was held on October 4 and 5, 2000 in Windsor, Ontario. The primary concerns to the members of the work group were reliable interpretations of the health data and statistics for the Health Canada reports, and the apparent absence of any comparable data for the AOCs in the United States.

The Workplan

• Review the 17 Great Lakes Health Effects reports to prepare a synthesis of the health status within the communities in the Canadian AOCs, with particular regard to the health status in Windsor.

• Examine the processes being employed in these communities to respond to this new information, with a focus on the response in Windsor.

• Inquire whether comparable U.S. data can be obtained.

• Examine how to obtain data on more subtle quality-of-life indicators within the AOC communities, including such health endpoints as thyroid dysfunction, diabetes and immune dysfunction.

• Obtain indirect evidence from monitoring the incidence of endocrine effects on wildlife populations that are geographically distributed close to AOCs.

• Investigate the possible links between the incidence of disease and exposures to pollutants.

• Investigate the associated societal costs.

Several past activities had been undertaken by the IJC and the governments to gain understanding of the Great Lakes health issues at the community level. In 1992, the Work Group on Ecosystem Health held a workshop titled Our Community, Our Health: Dialogue Between Science and Community . In 1995, Health Canada published two documents titled Investigating Human Community Exposure to Contaminants in the Environment and A Community Handbook. In 1999, the Great Lakes Science Advisory Board held a Meeting to Assess Scientific Issues in Relation to the Effects of Persistent Toxic Substances in Relation to Lakewide Management Plans , and identified the need to assemble epidemiological evidence related to the effects on human communities. Much of the work undertaken has traditionally related to the incidence of cancer. With the recent publication of several papers documenting the experimental induction of a variety of effects from prenatal exposures to low doses of endocrine disruptors, there is now a priority need for communities to investigate whether these subtle effects are occurring among individuals within their communities.

Community health and injury to health from exposures to pollutants connote environmental epidemiology. Epidemiology has been undergoing a period of intellectual crisis and reassessment (Susser and Susser, 1996a, b; Pearce 1996). The crisis has been precipitated by the limits of the methodology for detecting significant relationships between the incidences of disease and exposures to putative risk factors. The reassessment has been prompted by a recognition of the need to reconnect the science of

epidemiology with the practice of public health in its ongoing attempts to intervene effectively with large scale increases in the incidences of certain diseases of uncertain etiology. In the quest for making definitive causal statements relating disease incidences to specific factors, to determine whether preventive interventions are feasible, there has been a recognition of the need to develop an eco-epidemiological approach by integrating molecular epidemiology, with its orientation toward mechanistic hypotheses, with individual and population epidemiology, and to cast these in a social, economic and political context (Susser and Susser, 1996b). There are particular challenges of applying this new approach to environmental epidemiology, with all the attendant difficulties of measuring, estimating or inferring exposures (Pekkanen and Pearce, 2001). The International Joint Commission, comprised of the dual attributes of politics and science, first applied an eco-epidemiological methodology to several Great Lakes case histories in 1989, at its first Cause-Effect Linkages Workshop (Fox 1991).

Within the Great Lakes basin, the political context of the implementation of the Great Lakes Water Quality Agreement has not changed significantly since the early 1980s when the shift to the political right resulted in a general withdrawal of environmental issues from the political agenda of both countries. The consilience of results of so many epidemiological studies, together with the extensive surveys of the concentrations of persistent toxic substances in the Great Lakes environment, and the research on the mechanistic processes, has created a strong dynamic tension with the maintenance of these existing policies formulated more than 20 years ago. The workshop was structured to explore this consilience and lay out the diversity of evidence and implications of not implementing the restoration provisions of the Agreement. The papers from the Workshop on Methodologies for Community Health Assessment for Areas of Concern are being prepared for publication in the journal of the National Institute of Environmental Health Sciences, Environmental Health Perspectives.

One of the critical health endpoints from exposures of communities to toxic substances concerns the effects on neurological development. In his keynote address at the Workshop on Methodologies for Community Health Assessment for Areas of Concern , Ted Schettler, (Schettler et al. 1999) of the Greater Boston Physicians for Social Responsibility, elaborated the evidence of the unique vulnerability of the developing brain to environmental agents, such as organochlorine compounds and metals, at exposure levels that have no lasting effect in the adult. This has been known for a long time, since there are even biblical prohibitions against drinking alcohol because of the long-lasting damage to brain development and function caused by prenatal alcohol exposure. Where registries have been established, the collection of health information on behavioural, learning and developmental effects has been significantly enhanced.

Recommendation

The SAB recommends the following to the IJC.

• Recommend that the Parties establish prospective and retrospective registries of neurological deficits to identify subpopulations at risk from exposures to developmental toxicants.

Health Effects in Canadian Areas of Concern:
17 Health Canada Reports

The 17 Health Canada reports on health data and statistics for diseases and conditions that might be related to pollution in the communities in the Canadian AOCs, represent an enormous database that potentially could contribute to the formulation of statements that could provide a rational basis for remedial action plans to restore environmental quality under the Great Lakes Water Quality Agreement and under the Canada - United States Air Quality Agreement. The reports with the data and statistics can be found at http://www.hc-sc.gc.ca/ehp/ehd/bch/bioregional/healthdata.htm. Before the reports can be utilized for this or any other purpose, such as selecting community health indicators, they needed to be interpreted. The objective of the IJC Workshop on Methodologies for Community Health Assessment for Areas of Concern was to focus on methodologies. The secondary objective was to provide detailed descriptions of the community health status within AOCs. The following is a brief review of the methodology that Health Canada used to compile the reports and of the methodologies used to interpret the database. Health Canada detailed the methods used in the study under the following headings: Assigning Standard Geographic Codes; Selecting Health Outcomes; and Gathering and Analyzing the Data.

Assigning Standard Geographic Codes

Each of the 17 AOCs was described using Standard Geographic Codes that contain provincial, Census Division and Census Sub-Division information, and that coincide with the Canadian process for collection of human health data. Each of the 17 reports contained detailed background information on: the study area and its population; methods used in the study for assigning Standard Geographic Codes; and gathering associated health data. The population within each area in 1991 was determined and compared, as a percentage, with the Ontario provincial population, which was 10,104,317. Data for the incidence rates for diseases and disorders for the populations in all the AOCs were age standardized by gender and comparisons made with the incidence rates for the rest of Ontario.

Selecting Health Outcomes

Health Canada selected approximately 70 categories of health endpoints, using the International Classification of Diseases (ICD 1992). Because this project was undertaken by the former Great Lakes Health Effects Program under the mandate of the Great Lakes Water Quality Agreement, there was an orientation toward selecting diseases and disorders on the basis that they might plausibly be linked to exposures to contaminants in the Great Lakes environment based on references in the published literature. Appendix I. contains the selected health outcomes based on the Ninth Edition of the International Classification of Disease (1992).

Gathering and Analyzing the Data

Population census data for the years 1986 and 1991 were accessed from the Demography Division of Statistics Canada to calculate mortality and morbidity rates on an age-specific and gender-specific basis. Mortality data were provided to Health Canada's Center for Disease Control by Statistics Canada and included information on the cause of death, reported by ICD code, the last location of residence based on the Census Sub-Division, and the sex and age of the deceased. Hospital separations data were supplied by the Canadian Institutes for Health Information, and included data on sex, age and residence, and the ICD code for the diagnosis for the main cause of hospitalization. Health Canada warned about some of the pitfalls of using hospital separations data and these concerns included multiple visits or transfers between or within hospitals. They also exclude visits to clinics, doctor's offices and outpatient departments. Similarly, there may have been difficulties in transforming residence information, based on a postal code or an Ontario Residence Code, into a Census Sub-Division. Further, these data for Ontario do not include Ontario residents who were hospitalized in another province.

These pitfalls were addressed in the Health Canada reports in analyzing the data and statistics. For example, in using the hospital separations data, Health Canada referred to morbidity rates rather than incidence rates. The data were initially analyzed using 19 age groups, but for simplification of reporting were combined into five age categories: all ages; 0-24 years; 25-44 years; 45-74 years; and more than 75 years. The age adjusted mortality and morbidity rates were compared with the rates for the rest of Ontario and ratios calculated comparing the local rates with the provincial rates. In the 17 reports, Health Canada included numerous references to aid in the interpretation of the data and statistics. In addition, several of the reports of the former Great Lakes Health Effects Program of Health Canada (1995, 1997, 1998) proved invaluable in the interpretation of the 17 reports on the health data and statistics particularly in relation to possible causal factors, including occupational exposures to chemicals and lifestyle factors such as alcohol and smoking.

The interpretation of the reports has proved to be a challenge, even for those with advanced degrees in public health. The challenges can be divided into: those associated with the diversity of health outcomes selected; useful ways of aggregating the endpoints into categories; and interpretation of the tables into comprehensible displays and narratives. In the interpretation of the reports, the following three approaches have been taken by the Work Group on Ecosystem Health and its contractors:

a. mapping of the distribution of the statistical significance of the ratio of the incidence rate for a particular health endpoint compared with the rate in the rest of Ontario;

b. extended narrative of the elevated incidences of diseases or conditions within a population in a specific Area of Concern and comparisons with other locations with similar population size and racial profile; and

c. statistical analyses to rank Areas of Concern on the basis of the aggregated severity of incidences of diseases and conditions and to select indices of environmental health.

Mapping

Based on the Health Canada data and statistics, Dr. John Eyles of McMaster University prepared maps of the distribution of incidence rates for some of the diseases and conditions compared with the rest of the Ontario. He concluded that the Health Canada findings present a complex picture of health outcomes in the Canadian AOCs. In some respects, he felt, such a complex picture presents a scientific maze for policy makers in the IJC and in the federal and provincial bodies. There is so much that is potentially significant that it may be difficult to know where to concentrate finite and limited resources. While mapping the Health Canada statistical data provides a useful and user-friendly lens on the issues, there do remain methodological issues connected with the critical data and well documented as a series of caveats in the Health Canada reports themselves. Further, while the rates are usually standardized to the provincial population, this may not be the best comparator for a binational body like the IJC. It is of central importance to Ontario-based policy makers in public health and environmental regulation. And while the identification of statistical significance is important, such an approach may indicate issues of low incidence or even low public health relevance, given current knowledge and priorities.

Dr. Eyles compared the standardized rates, for the selected health outcomes for the various AOCs, with the rates for the rest of the Ontario. Those outcomes in which the ratios of the standardized rates were statistically significantly above one, were identified, based on the argument that any above average deviation from the province is worthy of note. This technique identified, for example, the Detroit River Area of Concern for both men and women, and the Niagara River (women only) as worthy of further investigation, even at the ecological level. Thus, it may be worth doing some analysis of census data to see the associations between some health determinants and the identified health outcomes. In this way, it will be possible to account for, at the ecological level, some of the non-environmental determinants of health. Further work will enable a discussion of potential explanations of the associations between different health outcomes and environmental factors operating in the Canadian AOCs.

Extended Narrative: Focus on Windsor, Ontario

Marcia Valiante of the University of Windsor set the historic context of the bilateral concerns about transboundary air pollution at the Detroit River. Windsor and the outlying areas have had poor air quality as a palpable fact of life for the last 100 years. This region is also subject to greater incidences of certain health problems than other areas in Ontario. Investigating the link between these two facts is like assembling a jigsaw puzzle with many pieces missing and no picture to guide the task of assembling the available information about the state of the air in this region and comment on the relationship between local and transboundary sources.

Marcia Valiante noted that Windsor is uniquely located. It is a city of 200,000 residents (with another 100,000 in neighboring communities in Essex County), yet it has air quality that is generally worse than that of the largest cities in Canada. This is in large part because Windsor's air quality is closely linked to emissions from industry and transportation sources in Detroit and the rest of southeast Michigan, in the larger upwind context of the Great Lakes basin. But Windsor is not simply a faultless victim of another jurisdiction's neglect; local industry and transportation sources also contribute harmful emissions to the atmosphere.

She pointed out that air pollution is usually regulated on the basis of its health impacts due to direct inhalation. Standards in both the U.S. and Canada reflect this traditional concern with air emissions. More recently, other concerns have emerged. Studies have shown that there is a proportionately significant contribution from atmospheric deposition to the Great Lakes for certain persistent substances, such as PCBs and mercury, which may then build up in the environment to harmful levels. As well, many substances no longer emitted locally are still detected in the air and water due to atmospheric transport from distant sources. Finally, the atmosphere allows for the transformation of some substances into other compounds that can then have effects far downwind. This is the case with acid rain and smog. While understanding all of these interrelationships is important to a complete picture of air pollution's impacts, it is difficult to get that complete picture due to major information gaps.

Of the 17 Canadian AOCs, Windsor, Ontario seems to be the municipality ranked among the highest for incidences of diseases that might be related to pollution. Jim Brophy of the Occupational Health Clinics for Ontario Workers and Michael Gilbertson of the International Joint Commission used the Health Canada health data and statistics for the Detroit River Area of Concern to provide an extended narrative of the incidence rates of mortality and of cancer, of morbidity as hospitalizations, and of congenital anomalies. Mortality and morbidity rates from all causes were higher than in the rest of the province. Anomalously high rates of diseases included: various cancers; endocrine, nutritional, metabolic and immunity disorders; and

diseases of the blood and blood-forming organs; nervous system and sense organs; circulatory and respiratory systems; digestive system; genitourinary system; skin and subcutaneous tissue; musculoskeletal system and connective tissues; congenital anomalies and infant mortality. These incidence rates for most diseases were