Chapter 3 Persistent Toxic Substances

The problems of persistent toxic substances (PTS) dominate three annexes of the Agreement: Annex 12 (Persistent Toxic Substances), Annex 14 (Contaminated Sediment), and Annex 15 ( Airborne Toxic Substances). The primary response of the Parties to persistent toxic substances is the Great Lakes Binational Toxics Strategy, which is discussed in Section 3.4.

3.1 Annex 12 - Persistent Toxic Substances

Annex 12 addresses definitions, general principles, programs, monitoring, early warning system, human health, research, and reporting. This annex embraces the philosophy of zero discharge and the goal of virtual elimination, and the Parties have achieved considerable success in controlling direct, point source discharges of toxic chemicals to the lakes. The Commission finds, however, that there are two remaining significant challenges to the virtual elimination of persistent toxic substances. The first is the historic burden of toxic chemicals in contaminated sediment; the second is the ongoing problem of airborne pollutants. The Parties' Great Lakes Binational Toxics Strategy does not adequately address either of these two remaining challenges.

The Commission's assessment of progress under Annex 12 examines the threat to human health, the early warning system, new and previously unidentified chemicals, chemical mixtures, and the general principles of the annex.

Threat to Human Health

The Parties have made progress in identifying the problems related to persistent toxic substances, most of which have human health implications. This work includes an increased understanding of the neurological, developmental, and trans-generational effects of some persistent toxic substances.

One of the main ways humans are exposed to persistent toxic substances in the Great Lakes basin is through consuming Great Lakes fish. Existing evidence demonstrates that the consumption of contaminated Great Lakes fish prior to and during pregnancy is associated with decreased birth weight and deficits in cognitive function in infants and children. Great Lakes fish contain many neurotoxins, including PCBs and methyl mercury, which can also produce interactive effects. These substances accumulate in the tissues of women and are transferred to the fetus during pregnancy and to infants during breast-feeding. Developing fetuses and nursing infants receive higher doses of toxic substances than at any other time in their lives. The subpopulations at greatest risk include First Nation and tribe members, sport fish anglers, and certain population groups who eat large quantities of Great Lakes fish. These facts raise the policy question of how best to protect human health, particularly for the more vulnerable sectors of the Great Lakes community.

A widely used governmental mechanism for addressing this policy question is the issuance of fish consumption advisories based on the current state of knowledge. The Great Lakes states have made significant advances in harmonizing their fish consumption advisories, taking into account the variation in concentrations of substances in different-sized fish of various species caught at different locations. Ontario advisories are based upon different sampling protocols from those used by the states and therefore sometimes provide different advice to consumers. The states of Ohio and Indiana both advise expectant and nursing mothers and children that "it is best to prevent exposure to fish contaminants in the first place" (Indiana State Department of Health and; Ohio Department of Health 2000). Fish consumption advisories assess risk and are not a guarantee of safety; and, there is always a danger that the advisory does not reflect the latest research. Over the past thirty years, fish advisories have generally become more restrictive as knowledge increased and more sensitive endpoints were reported from human health research.

The Commission has some very serious concerns about the injury to human health from exposures to contaminants in Great Lakes fish. The Commission is most interested in how the Parties can reduce exposures of susceptible subpopulations until ongoing programs achieve acceptable concentrations of persistent toxic substances in fish tissue. The Commission commends the states of Ohio and Indiana for adopting a precautionary approach in recognizing the particular dangers of these chemicals to the development of embryos, fetuses, infants, and children. The Commission sees the need for a straightforward statement consistent with the recommendations of Ohio and Indiana that, for women of child-bearing age and for children, it is best to prevent exposure to fish contaminants in the first place. The Commission is also concerned that advisories are not effectively distributed to women.

In the Commission's view, fish consumption advisories can only be an interim solution. They have been shown to have limited effectiveness among anglers, and, for First Nations and tribes, fishing is an integral component of culture and treaty rights. The long-term solution is clearly the restoration of the chemical integrity of the Great Lakes ecosystem to minimize exposure and subsequent bioaccumulation of persistent toxic substances in the tissue of fish. The Commission is asking its advisors to give further consideration to this matter over the next two years.

Figure 1 shows the dioxin-like activity of fish from Saginaw Bay compared to other foods. Appendix B illustrates the body of scientific knowledge to support a policy initiative in this area. The studies encompass the extent of human exposure to persistent toxic substances through consumption of fish and the subsequent effects of the substances.

THE COMMISSION RECOMMENDS THAT:

Governments should require that:

(i) sport fish consumption advisories state plainly that eating Great Lakes sport fish may lead to birth anomalies and other serious health problems for children and women of child-bearing age. These advisories should be addressed and distributed directly to women, in addition to their general distribution,

(ii) consumption advisories clearly identify fish to be totally avoided in light of the precautionary approach, and preparation methods for any that may be consumed, and

(iii) consumption advisories are supported by culturally appropriate community education programs directed to those who are likely to consume these fish.

Early Warning System

Another concern about Annex 12 relates to the reliability of models used to predict the ecosystem consequences of various loading rates of different persistent toxic substances. Computer simulations to identify the sources of these substances and their dispersal, fate, and distribution have advanced in the last few years.

In addition to simply estimating concentrations of chemical residues, the newer models incorporate monitoring data and consider indicators such as those based on fish, plants and nutrients. The modeling has been based on the physical and chemical properties of the molecules but requires monitoring data to confirm the predictions regarding the environmental fate and distribution of these substances. Furthermore, data deficiencies in discharge and emissions inventories, and inadequate information on chemical processes, increase the predictive uncertainty of the models. Models have proved adequate for planning research and monitoring, and have helped to elucidate source-receptor relationships to estimate the loading rates. Perhaps most important, the models point to the origin of loadings and indicate what actions need to be taken.

There is also very limited information indicating how much of a pollutant comes from a particular pathway and the relative importance of different sources to the loading contributions from a specific pathway. For example, there are limited measurements of dioxin in the Great Lakes atmosphere, and the air emissions inventories in both the United States and Canada are imperfect. As a result, scientists are unable to model atmospheric deposition of dioxin accurately. Dioxin is a sentinel toxic chemical for monitoring because it is detectable in trace quantities. Furthermore, an understanding of the relative importance of local, regional, national, continental, and global sources of certain persistent toxic substances is needed to make scientifically supportable policy decisions, particularly in planning and implementing remedial measures. There is a clear need for the Governments to increase their efforts to obtain this information. Without this information, it is unlikely that Agreement goals to reduce the loadings of persistent toxic substances can be effectively achieved by the Parties.

New Chemicals and Previously Unidentified Chemicals

Another aspect of an early warning system is the ability to identify chemicals new to commerce and previously unidentified chemicals that may cause future environmental problems. For example, although scientists can chemically extract chlorinated hydrocarbon residue from the tissue of Great Lakes fish and birds, they can only identify about 30 percent of the material they find. Several halogenated compounds as well as antibiotic and other pharmaceutical residues in Great Lakes samples remain unidentified. The presence of brominated diphenyl ethers, chlorinated paraffins and naphthalenes, and PCB metabolites in the tissue of a variety of species, ranging from snapping turtles and herring gulls to polar bears and humans, remains a mystery. Retrospective analysis of tissue samples from Great Lakes species deposited in specimen banks since the early 1970s may help to ascertain the source of these chemicals.

Chemical Mixtures

The question of chemical mixtures is also important. Human and other biotic communities are most often exposed to a "chemical soup" or mixture; only very rarely are they exposed to a single chemical. Many of these chemicals interact with each other externally in the environment or internally once inside the organism. How mixtures of chemicals affect exposed biota remains relatively unknown. Some chemicals behave either synergistically or antagonistically. In the absence of information on a specific mixture or combination, many regulatory agencies use a procedure first suggested by the U.S. National Academy of Sciences (1974) in which effects are assumed to be additive. This "default position" has withstood the test of time (over 25 years) and existing evidence often supports this position. However, this observation offers little comfort because of the multiplicity of combinations and permutations among chemicals in the environment.

The Parties should undertake research on the theoretical aspects of the chemical and physical properties of known substances that could produce synergistic or antagonistic effects when in mixtures. The Parties have used dioxin "equivalents" to evaluate mixtures of PCB isomers, dioxin, and furans, and the technique offers possibilities for evaluating the risk and effects of other chemical mixtures. The effects of mixtures is an area of research that the Commission believes will offer considerable help to the Parties as they work on identifying persistent toxic substances and their effects.

General Principles

Annex 12 refers to "General Principles." The first encompasses the well-known Agreement concepts of virtual elimination and zero discharge. The second principle, rehabilitation, acknowledges that virtual elimination and zero discharge are necessary, but not sufficient, to achieve Agreement goals. Rehabilitation recognizes the importance of addressing persistent toxic substances that are already present in the ecosystem and are causing adverse effects. Rehabilitation is generally achieved through remediation under the RAPs and LaMPs and cannot be addressed by the Parties' emphasis on pollution prevention policies and programs.

In its Seventh Biennial Report (1994), the Commission endorsed the work of its Virtual Elimination Task Force in the consideration of persistent toxic substances under Annex 12. At that time, the Commission noted that zero discharge means absolutely no release of chemicals, not merely "below the level of detection" of available analytical instrumentation. The Task Force also recognized the need to apply certain concepts, notably reverse onus, and a precautionary approach. These two ideas mean respectively that "a chemical is presumed harmful unless proven otherwise" and that "when there is a serious risk of environmental damage, even though scientific certainty has not been established, it is prudent to take (cost-effective) measures to reduce or eliminate the risk" (IJC 1993).

The Commission welcomes the addition of the concept of virtual elimination to the Canadian legislative framework. Canada has led in this regard by being one of the first countries in the world to incorporate the concept into federal policy and now into the revised Canadian Environmental Protection Act (CEPA). CEPA's effectiveness will depend, however, on how it is implemented and on the accompanying regulations which, for example, will need to define "persistence." The Commission prefers adoption of a definition consistent with the Agreement. Given the Commission's interpretation of the term "zero discharge" as literally zero discharge, the Commission will take a special interest in how Environment Canada sets the Levels of Quantification in the CEPA regulations, in conjunction with provisions in other sections of CEPA that can be used to ban the manufacture, import, export, and use of designated persistent toxic substances.

3.2 Annex 14 - Contaminated Sediment

The persistent toxic substances found in contaminated sediment are the dominant issue in the Areas of Concern. Annex 14 requires that the information obtained through research and studies under this annex guide the development of RAPs and LaMPs.

Sediment remediation is a large-scale, high-cost problem throughout the Great Lakes basin. Beginning with the 1975 final report of the IJC International Working Group on the Abatement and Control of Pollution from Dredging Activities, the Commission has sponsored numerous technical workshops and received extensive advice from expert committees. In 1999, the Great Lakes Water Quality Board's Sediment Priority Action Committee (SedPAC) identified obstacles to sediment remediation and developed data interpretation tools to support sediment management decisions. In addition, SedPAC offered several recommendations to improve ecological assessment and monitoring programs to enhance recovery forecasting and benefit measurement.

The policy and program requirements needed to support a binational program for the management of contaminated sediment are clearly articulated under Annex 14. They include comprehensive problem definition, development of common assessment methodologies, review of contaminated sediment classification practices, establishment of compatible criteria for sediment quality classification, development of biological indicators, development of a standard approach and management procedures, cooperative technology assessment, design and implementation of demonstration projects at selected Areas of Concern, and establishment of measures for long-term disposal and beneficial reuse of contaminated sediment.

The Commission notes that the Parties have accomplished some of the elements required in Annex 14. For example, the U.S. and Canada adopted similar classification practices and compatible criteria for remediating contaminated sediment. However, the emphasis on site-specific characteristics in each AOC has resulted in wide variations in remediation practices. This was evident when the Commission compared remediation projects in the Black River in the United States and Hamilton Harbour in Canada. There were significant differences in the final levels of polycyclic aromatic hydrocarbons (PAHs) in these two AOCs. In the Black River, sediment removal resulted in final PAH concentrations in the remaining sediment ranging between 6 and 37 mg/kg. As a result, Black River fish show significantly fewer tumors than previously noted. (Ohio Environmental Protection Agency 1999) In contrast, the Randle Reef Project in Hamilton Harbour proposes a final PAH concentration of 700 mg/kg. This level is well above the objectives achieved for the Black River and the lowest effect levels based on Canadian guidelines.

That the PAH level allowed for the Randle Reef project is considerably higher than the upper limit of the range for the Black River is inconsistent from both a scientific and policy perspective. PAHs are established carcinogens and, as demonstrated by remediation efforts in the Black River, minimizing their allowable residue in biota and environmental media advances the goal of restoration.

The situation of the Hamilton Harbour AOC is more complex than that of the Black River because, in addition to PAHs, fish consumption advisories are in place in Hamilton Harbour for PCBs, mercury, and mirex. There also are documented sources of dioxin in air emissions from the Stelco sintering plant. The Commission is concerned that the proposal to incinerate pretreated contaminated sediments in the same sintering plant could lead to the production and release of more dioxins. These conditions provide a good example of the problem of chemical mixtures. A more holistic analysis, utilizing the precautionary approach applied to human health concerns for multiple bioaccumulative chemicals, would assist in this case. As recommended by the Great Lakes Water Quality Board, this situation would also benefit from close post-project monitoring.

Natural Recovery

Although SedPAC noted the need to consider natural recovery as a viable cleanup option, the issue is potentially contentious. Natural recovery can take as few as five years, for example, to eliminate kepone in the James River, Virginia, or well over 10,000 years to eliminate substances such as radioactive waste. This range of recovery time warns of the need for a careful analysis of the approaches being considered. It would also be important for an effective public outreach effort to determine that a cleanup that could take several generations would be acceptable to a well-informed public.

Current Status

The Commission has summarized progress related to sediment remediation in Areas of Concern. Clearly, the problem remains significant. Less than 2.4 percent of known contaminated sediment by volume in U.S. AOCs is remediated while, in Canada, the amount is only 0.2 percent (See Figures 2 and 3). The Parties have adopted some elements of Annex 14 (Contaminated Sediment) and are cooperating with respect to technology programs. However, they have not developed standard approaches, agreed management procedures, and long-term measures related to disposal and sediment reuse as required by the Agreement. The Commission concludes that the initiatives related to both RAPs (Annex 2) and contaminated sediment (Annex 14) require a long-term, binational effort and program that reflects the magnitude of the contaminated sediment challenge.

THE COMMISSION RECOMMENDS THAT:

Governments should immediately develop a comprehensive, binational program to address the full scope of the contaminated sediment problem over the long term, setting appropriate priorities and defining the resources required for completion. As part of this comprehensive program, governments should ensure that:

(i) programs and cost estimates are in place and made public for fully addressing contaminated sediments in Areas of Concern,

(ii) timetables for fully implementing those programs are established and made public,

(iii) resources are provided to fully implement the programs in accordance with the established timetables, and

(iv) progress reports are issued at least biennially.

Figure 2

Contaminated Sediment in the Great Lakes Areas of Concern

Figure 3

Management Status of Contaminated Sediment in Areas of Concern

All quantities are in million cubic metres

Source: Compiled by Commission staff, based on the best available estimates.

3.3 Annex 15 - Airborne Toxic Substances

Annex 15 recognizes that the atmosphere is a major pathway by which persistent toxic substances reach the Great Lakes. This annex includes provisions for research, monitoring, and modeling and establishes the components of the Integrated Atmospheric Deposition Network (IADN).

It is essential to place the atmospheric contribution to the pollution of the Great Lakes in the context of the total pollutant sources and the pathways that bring such pollutants to the lakes. Such determinations are needed to partially fulfill commitments by the Governments under Annex 15 of the Agreement. In addition, the Great Lakes Binational Toxics Strategy makes commitments to determine and manage the numerous sources of these contaminants. These determinations would support the further analysis of exposure and risk of pollutants, the development of regulatory controls, and the ultimate redesign of industrial processes to reduce and prevent discharges and emissions.

Airborne pollutants deposited in the lakes originate from both local and distant sources. The pollutants enter the atmosphere from direct emissions (smokestacks, combustion, automobiles) or through volatilization and evaporation from terrestrial or aquatic surfaces. The atmosphere transports the pollutants as particles, aerosols, or gases and the pollutants can be deposited directly onto solid or aquatic surfaces (dry deposition), or washed out of the atmosphere by rain and snowfall (wet deposition). A few pollutants remain suspended in the atmosphere for such a long period of time that they become part of a "regional or global background" level of pollution.

The relative importance of air as a pathway depends on the nature and number of the other pollutant sources in a given location. Lake Superior has relatively few point sources and the largest surface area. Because the deposition of material from the atmosphere is directly proportional to the surface area, Lake Superior receives a large percentage of selected persistent toxic substances via air deposition.

Integrated Atmospheric Deposition Network

To determine the significance of the atmosphere in the distribution and behavior of toxic contaminants in the Great Lakes, the Parties, principally the U.S. Environmental Protection Agency and the Atmospheric Environment Service (Canada), created the Integrated Atmospheric Deposition Network (IADN). This network combined "master" and "satellite" stations, as recommended in the Commission's 1988 Plan for Assessing Atmospheric Deposition to the Great Lakes.

The operation of IADN is an excellent example of a binational program that generates both comparable and compatible monitoring data on both sides of the international boundary. Locations were chosen for the master and satellite stations to allow quantification of the level of regional background for selected persistent toxic substances. One of those pollutants, mercury, in its elemental form volatilizes easily. Many of the organic compounds of mercury share this volatility characteristic. Thus, mercury and its compounds are contaminants requiring a "regional background" assessment as a vital piece of information for setting control strategies and regulatory approaches. However, IADN does not currently include mercury among the measured pollutants. This situation reflects the historical limitation on resources because, until recently, mercury analysis of air samples was very expensive.

Similar cost considerations were also cited in the exclusion of dioxin from the IADN roster. More recent analytical methods for mercury and dioxin appear less costly and, given the ongoing efforts to model the transport of these two contaminants to the lakes, enhancement of the network by inclusion of mercury and dioxin in the program should again be considered.

Although IADN is a significant achievement, success in the surveillance and research aspects of Annex 15 has been limited over the last decade because important components, such as emissions inventories and research, have not been pursued to the extent that they would enable the Parties to meet their obligations under this annex.

Linking Distant Sources to the Lakes

To assist the Parties in the development of source-receptor and air trajectory modeling, the International Air Quality Advisory Board (IAQAB) of the Commission supported application of the NOAA HYSPLIT (Hybrid Single Particle LaGrangian Integrated Trajectory) model to quantify dioxin contamination from sources internal and external to the Great Lakes basin.

HYSPLIT is capable of viewing atmospheric deposition from two perspectives. Starting with a source of emissions, such as a coal-fired plant in the U.S. midwest, the model estimates what fraction of those emissions will arrive (be deposited) at a specific site, such as Lake Michigan. Alternatively, starting with a site such as Lake Michigan, the model could determine likely airborne sources of a given pollutant and the relative significance of each source.

HYSPLIT depends upon the availability of several supporting elements, including a good-quality emissions inventory, adequate simulation of the behavior of the pollutant in the atmosphere, and the availability of ambient measurements for calibration and verification. Despite the limited data on emission inventories and ambient measurements, as described in the 1997-99 Priorities and Progress under the Great Lakes Water Quality Agreement Report (IJC 1999d; Cohen, M. and Commoner, B. 1995), the model outputs have been found to be reasonable and realistic for dioxin. If the supporting elements are improved, HYSPLIT or similar models could be a useful mechanism to establish the amount and relative significance of long-range atmospheric transport to the total burden of airborne persistent toxic pollutants in the Great Lakes.

The Commission is confident that the tools exist or can be further developed to determine the contribution of local, regional, continental, and global sources to the atmospheric deposition of persistent toxic substances into the Great Lakes basin. Some of these tools include those identified earlier -- HYSPLIT and IADN and their supporting elements, including emissions inventories, physical and chemical determinations, and other ambient measurements.

THE COMMISSION RECOMMENDS THAT

The Parties should take the following measures to deal with airborne pollutants:

(i) identify both in-basin and out-of-basin sources of atmospheric deposition of persistent toxic substances to the Great Lakes, quantify their contribution to the total burden of these substances to the lakes, and use this information to formulate and implement appropriate prevention and control measures; and

(ii) adopt a source-receptor computer model, improve emissions inventory information, and add dioxin and mercury to the Integrated Atmospheric Deposition Network to improve the data bases for these two substances.

3.4 The Great Lakes Binational Toxics Strategy

The Great Lakes Binational Toxics Strategy ("the Strategy"), signed on April 7, 1997, established a collaborative process between the Parties and stakeholders to address the goal of virtual elimination of targeted persistent toxic substances in the Great Lakes basin. The strategy uses three processes to facilitate consultation: substance-specific workgroups, stakeholder forums, and an integration workgroup. An underlying tenet of the Strategy is that the Governments cannot achieve the goal of virtual elimination by their actions alone. Thus, it "challenges all sectors of society to participate and cooperate to ensure success" (U.S. Environmental Protection Agency and Environment Canada 1997).

The work of the substance-specific workgroups comprises the core activity under the Strategy. Meetings with stakeholders are held twice a year to encourage an open participatory process of consultation on Strategy implementation. The Integration Workgroup functions to provide oversight and coordination and to discuss other issues that may fall outside the scope of the substance-specific workgroups.

The Mercury Workgroup

The Mercury Workgroup, one of the seven substance-specific workgroups, has effectively mobilized the activities of a broad spectrum of stakeholders. The group aims to reduce and eliminate mercury use and disposal in the environment. This includes eliminating mercury from such diverse sources and sectors as sewage treatment plants, electric utilities, schools, the metals industry, health care, mining, and industrial production processes. It also involves removal of mercury from a variety of commercial products and household uses, such as medical thermometers, thermostats, lamps, appliances, automobiles, and switches. The group accomplishes this work through initiatives involving joint activities with, for example, the Commission for Environmental Cooperation, the Chlorine Institute, and the steel industry. Community outreach and education activities are also undertaken by promoting better disposal methods that emphasize life-cycle analysis of mercury-containing products.

The control of mercury, one of the persistent toxic pollutants, represents one of the success stories of the Strategy. Significant reductions have been reported. The workgroup has established a mercury Internet web site, which provides information on sources and regulations by topic and sector. In addition to the impact of its direct initiatives, the workgroup has helped in expanding knowledge about the chemical, environmental, and human health effects of this material, and about its sources and environmental behavior. The workgroup has also benefitted from the work of a well-networked group of researchers from Labrador to Florida on the Atlantic coast and from Alaska to southern California on the Pacific coast. In addition, the electric power industry has an established network of researchers; fossil fuel, mainly in coal-fired power plants, is one of the major sources of mercury emissions to the environment.

Progress in environmental control of mercury has occurred despite the fact that IADN does not include mercury in its program. If IADN included mercury, the workgroup could estimate loadings of mercury to the Great Lakes, thereby assessing the ecosystem effects of its reduction efforts.

Other Workgroup Progress

Workgroups created by the Strategy are also addressing the other eleven designated persistent toxic substances. After three years, however, no workgroup has entirely completed the four-step process. For example, the PCB Workgroup is currently focusing on steps 3 and 4, but has only documented actions for the reduction of PCB inventories currently in use or in storage. This initiative does not address PCBs in sediments or the deposition of PCBs from long-range sources via the atmosphere. Although PCBs in use and in storage may constitute a potential long-term threat, PCBs circulating in biota cause the greatest immediate harm to Great Lakes fish, wildlife and humans.

Similarly, the Dioxin/Furan Workgroup has been unable to quantify sources of these substances to the Great Lakes as a basis to determine priorities for action. Major source reductions of dioxin are estimated based on new national standards in the United States and Canada primarily related to incineration. Another major source reduction in Canada was recently achieved by process changes in the pulp and paper industry that avoid the use of elemental chlorine in bleaching. Without quantified estimates of the contributions of all sources to the Great Lakes, however, strategic and cost-effective reduction opportunities cannot be identified with certainty. As an illustration, pollution prevention initiatives to restrict open burning and replace older technology woodstoves may represent greater or fewer opportunities for reductions than programs targeting other sources. Given that the state of knowledge and available data for PCBs and dioxins are somewhat advanced, the Commission encourages the Governments to adopt a more strategic approach with these substances to ensure that adequate data, information, and research are made available to the workgroups to support them in moving forward decisively to steps 3 and 4 in the process.

Deficiencies of the Strategy

The Commission recognizes the significant yet disparate effort being sustained in the Strategy, and it is concerned that the effectiveness of the Parties' efforts are being compromised by inadequate data and information on sources. The Strategy places emphasis on the substance-specific workgroups to address reduction opportunities separately for each substance, which can limit the ability of the Integration Workgroup to adopt an overall strategic approach. The Commission is sensitive to the fact that any and all reductions of persistent toxic substances are worth pursuing. However, setting priorities for the virtual elimination of the targeted substances may be the most effective manner to reduce significant or important sources of the pollutant. This issue can be addressed with improved data, information, and reporting with respect to steps 1 and 2 of the Strategy's four-step analytical process. Greater emphasis on sources and emissions could lead to a more strategic approach and would make major inroads into producing effective overall emission inventories. The effectiveness of steps 3 and 4 of the process for all the substances would also be improved with greater oversight of the Integration Workgroup, using the stakeholder forums to assist with policy implementation.

In an attempt to advance the state of knowledge with respect to the sources and transport of persistent toxic substances to the Great Lakes, the Commission's IAQAB undertook an analysis of dioxin deposition in the Great Lakes. The Board recognized the need for a comprehensive, binational emissions inventory of in-basin and out-of-basin point sources and source regions of this contaminant. By bringing together experts from federal, provincial, and state governments, this inventory and associated binational digital maps were produced, which then allowed the modeling of dioxin deposition to the lakes, and the accompanying identification of significant sources and source regions.

The IAQAB also assembled a U.S. county emissions data base for several of the persistent toxic substances of concern as well as a preliminary compilation of related control programs and outcomes for both the United States and Canada. The IAQAB has demonstrated the feasibility of this type of analysis and the Commission recommends that the Governments utilize a similar technique to advance further their knowledge and understanding of the air pathway as it applies to the Strategy.

This work of the IAQAB has demonstrated that the resources and technology exist within the Governments to rigorously pursue the goal of virtual elimination under the Strategy in a truly binational manner. The Commission believes that a reliance on actions to reduce persistent toxic substances discharges through pollution prevention, while necessary, is not sufficient to enable the Parties to fulfill their obligations under the Agreement.

THE COMMISSION RECOMMENDS THAT:

The Parties should strengthen the Great Lakes Binational Toxics Strategy by fully addressing all sources of persistent toxic substances, such as atmospheric transport and deposition and in situ contaminants in sediments. In order to include the air pathway the Parties should:

i) establish an inventory of baseline air emissions for toxics for all of the United States and Canada.

ii) undertake a complete analysis of emission reduction scenarios for key source regions and determine their effectiveness in reducing contamination of the Great Lakes from the air.

The Parties should ensure that the Strategy is truly both strategic and binational by strengthening the integration and priority setting component and establishing a full-time binational secretariat.